load control

Load Control RAN12.0

Feature Parameter Description

Issue 02

Date 2010-12-20

HUAWEI TECHNOLOGIES CO., LTD.

Copyright © Huawei Technologies Co., Ltd. 2011. All rights reserved.

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WCDMA RAN

Load Control Contents

Issue 02 (2010-12-20) Huawei Proprietary and Confidential

Copyright © Huawei Technologies Co., Ltd

iii

Contents

1 Introduction ................................................................................................................................ 1-1

1.1 Scope ............................................................................................................................................ 1-1

1.2 Intended Audience ........................................................................................................................ 1-1

1.3 Change History .............................................................................................................................. 1-1

2 Overview of Load Control ....................................................................................................... 2-0

2.1 Overview ....................................................................................................................................... 2-0

2.2 Load Control in Different Scenarios .............................................................................................. 2-0

2.3 Function Introduction ..................................................................................................................... 2-0

2.4 Priorities Involved in Load Control ................................................................................................ 2-2

2.4.1 User Priority .......................................................................................................................... 2-2

2.4.2 RAB Integrated Priority ......................................................................................................... 2-3

2.4.3 User Integrated Priority ......................................................................................................... 2-3

3 Load Measurement ................................................................................................................... 3-1

3.1 Load-Related Measurement Quantities ........................................................................................ 3-1

3.2 Reporting Period ........................................................................................................................... 3-2

3.3 Load Measurement Filtering ......................................................................................................... 3-2

3.3.1 Layer 3 Filtering on the NodeB Side .................................................................................... 3-2

3.3.2 Smooth Filtering on the RNC Side ....................................................................................... 3-3

3.4 Auto-Adaptive Background Noise Update Algorithm..................................................................... 3-4

4 Potential User Control ............................................................................................................. 4-1

5 Intelligent Access Control ...................................................................................................... 5-1

5.1 Overview of Intelligent Access Control .......................................................................................... 5-1

5.2 IAC During RRC Connection Setup .............................................................................................. 5-3

5.2.1 Procedure of IAC During RRC Connection Setup ................................................................ 5-3

5.2.2 RRC Redirection based on Distance .................................................................................... 5-5

5.2.3 RRC Redirection for Service Steering .................................................................................. 5-6

5.2.4 RRC DRD ............................................................................................................................. 5-7

5.2.5 RRC Redirection After DRD Failure ..................................................................................... 5-8

5.3 Directed Retry Decision ................................................................................................................ 5-9

5.4 Rate Negotiation at Admission Control ......................................................................................... 5-9

5.4.1 PS MBR Negotiation ............................................................................................................. 5-9

5.4.2 PS GBR Negotiation ............................................................................................................. 5-9

5.4.3 Initial Rate Negotiation ....................................................................................................... 5-10

5.4.4 Target Rate Negotiation ...................................................................................................... 5-12

5.5 Admission Decision ..................................................................................................................... 5-12

5.6 Preemption .................................................................................................................................. 5-12

5.6.1 Common Preemption .......................................................................................................... 5-12

5.6.2 Forced Preemption ............................................................................................................. 5-13

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5.7 Queuing ....................................................................................................................................... 5-14

5.8 Low-Rate Access of the PS BE Service ...................................................................................... 5-15

5.9 IAC for Emergency Calls ............................................................................................................. 5-17

5.9.1 RRC Connection Setup Process of Emergency Calls ........................................................ 5-17

5.9.2 RAB Process of Emergency Calls ...................................................................................... 5-17

6 Intra-Frequency Load Balancing .......................................................................................... 6-1

7 Load Reshuffling ....................................................................................................................... 7-1

7.1 Basic Congestion Triggering ......................................................................................................... 7-1

7.1.1 Power Resource ................................................................................................................... 7-1

7.1.2 Code Resource ..................................................................................................................... 7-2

7.1.3 Iub Resource ........................................................................................................................ 7-2

7.1.4 NodeB Credit Resource ....................................................................................................... 7-2

7.2 LDR Procedure .............................................................................................................................. 7-3

7.3 LDR Actions ................................................................................................................................... 7-6

7.3.1 Inter-Frequency Load Handover .......................................................................................... 7-6

7.3.2 BE Rate Reduction ............................................................................................................... 7-9

7.3.3 QoS Renegotiation for Uncontrollable Real-Time Services ................................................. 7-9

7.3.4 Inter-RAT Handover in the CS Domain .............................................................................. 7-10

7.3.5 Inter-RAT Handover in the PS Domain .............................................................................. 7-10

7.3.6 AMR Rate Reduction ...........................................................................................................7-11

7.3.7 Code Reshuffling .................................................................................................................7-11

7.3.8 MBMS Power Reduction .................................................................................................... 7-13

7.3.9 UL and DL LDR Action Combination of a UE ..................................................................... 7-13

8 Overload Control ....................................................................................................................... 8-1

8.1 Overload Triggering ....................................................................................................................... 8-1

8.2 General OLC Procedure ............................................................................................................... 8-2

8.3 OLC Actions .................................................................................................................................. 8-3

8.3.1 Performing TF Control of BE Services ................................................................................. 8-3

8.3.2 Switching BE Services to Common Channels ..................................................................... 8-4

8.3.3 Adjusting the Maximum FACH TX Power ............................................................................. 8-5

8.3.4 Releasing Some RABs ......................................................................................................... 8-5

9 Parameters ................................................................................................................................. 9-1

10 Counters ................................................................................................................................. 10-1

11 Glossary .................................................................................................................................. 11-1

12 Reference Documents ......................................................................................................... 12-1

WCDMA RAN

Load Control 1 Introduction



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1 Introduction

1.1 Scope

This document describes the features related to the load control. It also describes the related parameters.

1.2 Intended Audience

This document is intended for:

Personnel who are familiar with WCDMA basics

Personnel who need to understand load control

Personnel who work with Huawei products

1.3 Change History

This section provides information on the changes in different document versions.

There are two types of changes, which are defined as follows:

Feature change: refers to the change in the load control feature.

Editorial change: refers to the change in wording or the addition of the information that was not described in the earlier version.

Document Issues

The document issues are as follows:

02 (2010-12-20)

01 (2010-03-30)

Draft (2009-12-05)

02 (2010-12-20)

This is the document for the second commercial release of RAN12.0.

Compared with issue 01 (2010-03-30) of RAN12.0, this issue incorporates the changes described in the following table.

Change Type Change Description Parameter Change

Feature change The description about RRC redirection for service steering is optimized. For details, see 5.2.3 "RRC Redirection for Service Steering."

None.

The information about forced preemption is added. For details, see 5.6 “Preemption.”

None.

Editorial change The description of this document is optimized. None.

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01 (2010-03-30)

This is the document for the first commercial release of RAN12.0.

Compared with issue Draft (2009-12-05) of RAN12.0, this issue incorporates the changes described in the following table.


Feature change The description about RRC redirection based on distance is added. For details, see 5.2.2 "RRC Redirection based on Distance."

The added parameters are listed as follows:

RedirSwitch

DelayThs

RedirFactorOfNorm

RedirFactorOfLDR

The description about PS GBR negotiation is optimized. For details, see 5.4.2 "PS GBR Negotiation."

None.

Editorial change None. None.

Draft (2009-12-05)

This is the draft of the document for RAN12.0.

Compared with issue 02 (2009-06-30) of RAN11.0, this issue incorporates the changes described in the following table.


Feature change The information about the algorithms in load control describing how to deal with DC-HSDPA users, is added.

None.

The criterion of selecting UEs for inter-frequency load handover is changed in section 7.3.1 "Inter-Frequency Load Handover."


InterFreqLdHoForbidenTC

The inter-frequency load handover based on measurement is added. For details, see section 7.3.1 "Inter-Frequency Load Handover."


InterFreqLDHOMethodSelection

DrdOrLdrFlag

PrdReportInterval

TargetFreqThdRscp

TargetFreqThdEcN0

InterFreqMeasTime

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Editorial change The information about Directed Retry Decision (DRD) is transferred to the Directed Retry Decision Feature Parameter Description.

The information about the related parameters are also transferred to the Directed Retry Decision Feature Parameter Description.

The information about Call Admission Control (CAC) is transferred to the Call Admission Control Feature Parameter Description.

The information about the related parameters are also transferred to the Call Admission Control Feature Parameter Description.

The information about dynamic power sharing among carriers is transferred to the Dynamic Power Sharing Among Carriers Feature Parameter Description.

The information about the related parameters are also transferred to the Dynamic Power Sharing Among Carriers Feature Parameter Description.

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Call%20Admission%20Control.htm




Dynamic%20Power%20Sharing%20Among%20Carriers.htm





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Load Control 2 Overview of Load Control



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2 Overview of Load Control

2.1 Overview

The WCDMA system is a self-interfering system. As the load of the system increases, the interference rises. A relatively high interference can affect the coverage of cells and QoS of established services. Therefore, the capacity, coverage, and QoS of the WCDMA system are mutually affected.

By controlling the key resources, such as power, downlink channelization codes, channel elements (CEs), Iub transmission resources, which directly affect user experience, load control aims to maximize the system capacity while ensuring coverage and QoS.

Load control function controls the load in a cell. Each cell has its own set of load control functions that are responsible for monitoring and controlling the resources of the cell. The load control functions monitor the load condition of the cell through load measurement, make the admission decision for services through intelligent access control and call admission control, and thus relieve congestion in a cell.

2.2 Load Control in Different Scenarios

Depending on the actual phase of UE access, different load control functions are used, as shown in the following figure.

Figure 2-1 Load Control functions in different UE access phases

The load control functions are applied to different UE access phases as follows:

Before UE access: Potential User Control (PUC)

During UE access: Intelligent Access Control (IAC) and Call Admission Control (CAC)

After UE access: intra-frequency Load Balancing (LDB), Load Reshuffling (LDR), and Overload Control (OLC)

The following sections will provide detailed information about the load control functions performed in the different UE access phases.

2.3 Function Introduction

„Load control is implemented in the RNC after obtaining measurement reports from the NodeBs.

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Figure 2-2 Load control function in the WCDMA system

The load control functions are described as follows:

Potential User Control (PUC)

The function of PUC is to balance traffic load between cells on different frequencies. The RNC uses PUC to modify cell selection and reselection parameters, and broadcasts them through system information. In this way, UEs are led to cells with light load. The UEs can be in idle mode, CELL_FACH state, CELL_PCH state, or URA_PCH state.

Intelligent Access Control (IAC)

The function of IAC is to increase the access success rate with the current QoS guaranteed through rate negotiation, queuing, preemption, and Directed Retry Decision (DRD). For details about DRD, see the Directed Retry Decision Feature Parameter Description.

Call Admission Control (CAC)

The function of CAC is to decide whether to accept resource requests from UEs, such as access, reconfiguration, and handover requests, depending on the resource status of the cell.

For details about CAC, see the Call Admission Control Feature Parameter Description.

Intra-frequency Load Balancing (LDB)

The function of intra-frequency LDB is to balance the cell load between neighboring intra-frequency cells to provide better resource usage. When the load of a cell increases, the cell reduces its coverage to lighten its load. When the load of a cell decreases, the cell extends its coverage so that some traffic is off-loaded from its neighboring cells to it.

Load Reshuffling (LDR)

The function of LDR is to reduce the cell load when the cell enters the basic congestion state. The purpose of LDR is to increase the access success rate by taking the following actions:

− Inter-frequency load handover

− Code reshuffling

− BE service rate reduction

− AMR voice service rate reduction

− QoS renegotiation for uncontrollable real-time services

− CS inter-RAT load handover

− PS inter-RAT load handover

− MBMS power reduction

Overload Control (OLC)

The function of OLC is to reduce the cell load rapidly when the cell is overloaded. The purpose of OLC is to ensure the system stability and the QoS of most UEs in the following ways:



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− Restricting the Transport Format (TF) of the BE service

− Switching BE services to common channels

− Adjusting the maximum transmit power of FACHs

− Releasing some RABs

Table 2-1 lists the resources that are considered by different load control functions.

Table 2-1 Resources considered by different load control functions

Load Control Function Resources

Power Code NodeB Credits Iub Bandwidth

CAC √ √ √ √

IAC √ √ √ √

PUC √ - - -

LDB √ - - -

LDR √ √ √ √

OLC √ - - √

NOTE

- : not considered

√: considered

2.4 Priorities Involved in Load Control

Different types of priorities are used in load control to preferentially ensure the QoS of the services or users with high priorities.

The priorities involved in load control are user priority, Radio Access Bearer (RAB) integrated priority, and user integrated priority.

2.4.1 User Priority

User priorities are adopted to provide differentiated services for users. For ease of application, the RNC maps the 15 levels of Allocation/Retention Priority (ARP) that is carried in the RAB ASSIGNMENT REQUEST message from the core network (CN) onto three user priorities, that is, gold (high priority), silver (medium priority), and copper (low priority). The relation between user priority and ARP can be set by running SET UUSERPRIORITY command; the typical relation is shown in Table 2-2.

Table 2-2 Typical relation between user priority and ARP

ARP 1 2 3 4 5 6 7 8

User Priority Gold Gold Gold Gold Gold Silver Silver Silver

ARP 9 10 11 12 13 14 15

User Priority Silver Silver Copper Copper Copper Copper Copper

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If ARP is not received in messages from the Iu interface, the user priority is regarded as copper.

2.4.2 RAB Integrated Priority

The priority of a RAB is determined by its traffic class, ARP, and carrier type. Such a priority is called RAB integrated priority. When resources are insufficient, services with the highest integrated priority are preferentially processed.

The values of RAB integrated priority are set according to the integrated priority configuration reference parameter (PriorityReference):

If PriorityReference is set to Traffic Class, the integrated priority abides by the following rules:

− Traffic classes: conversational > streaming > interactive > background

− Services of the same traffic class: priority based on ARP, that is, ARP1 > ARP2 > ARP3 > ... > ARP14 > ARP15

− Service of the same traffic class and ARP (only for interactive services): priority based on Traffic Handling Priority (THP) that is carried in the RAB ASSIGNMENT REQUEST message, that is, THP1 > THP2 > THP3 > ... > THP14 > THP15

− Services of the same traffic class, ARP and THP (only for interactive services): High Speed Packet Access (HSPA) or Dedicated Channel (DCH) service preferred depending on CarrierTypePriorInd.

If PriorityReference is set to ARP, the integrated priority abides by the following rules:

− ARP: ARP1 > ARP2 > ARP3 > ... > ARP14 >ARP15

− Services of the same ARP: priority based on traffic classes, that is, conversational > streaming > interactive > background

− Only for the interactive service of the same ARP value: priority based on Traffic Handling Priority (THP), that is, THP1 > THP2 > THP3 > ... > THP14 > THP15

− Services of the same ARP, traffic class and THP (only for interactive services): HSPA or DCH service preferred depending on CarrierTypePriorInd.

2.4.3 User Integrated Priority

A user may have multiple RABs, and the RABs may have different priorities. In this case, the highest priority is considered as the priority of this user. Such a priority is called user integrated priority. User integrated priority is used in user-specific load control. For example, the selection of R99 users during preemption, the selection of users during inter-frequency load handover for LDR, and the selection of users during switching of BE services to common channels are performed according to the user integrated priority.

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Load Control 3 Load Measurement



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3 Load Measurement

This chapter describes the WRFD-020102 Load Measurement Feature.

The load control functions, such as OLC and CAC, use load measurement values in the uplink and the downlink. A common Load Measurement (LDM) function is used to control load measurement in the uplink and the downlink separately.

Load measurement is implemented by the NodeB. The filtering of measurement quantities is implemented by the NodeB and the RNC.

3.1 Load-Related Measurement Quantities

The major load-related measurement quantities are as follows:

Uplink Received Total Wideband Power (RTWP)

Downlink Transmitted Carrier Power (TCP)

Non-HSPA power: TCP excluding the power used for transmission on HSPA channels. For the detailed information about HSPA channels, see the HSDPA Feature Parameter Description and the HSUPA Feature Parameter Description

Provided Bit Rate (PBR) on HS-DSCH. For details about PBR, see the 3GPP 25.321.

Power Requirement for GBR (GBP) on HS-DSCH: minimum power required to ensure the GBR on HS-DSCH

PBR on E-DCH

Received Scheduled E-DCH Power Share (RSEPS): power of the E-DCH scheduling service in the serving cell

The NodeB measures the major quantities related to load control. After layer 1 and layer 3 filtering, the measurement values are reported to the RNC through the COMMON MEASUREMENT REPORT message.

The RNC performs smooth filtering of the measurement values reported from the NodeB and then obtains the measurement values, which further serve as data input for the load control algorithms.

The measurement procedure is shown in Figure 3-1.

Figure 3-1 LDM procedure

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HSUPA.htm

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3.2 Reporting Period

The NodeB periodically reports each measurement quantity to the RNC. The following table lists the reporting period parameters for setting different measurement quantities.

Measurement Quantity Reporting Period Parameter

RTWP ChoiceRprtUnitForUlBasicMeas

TenMsecForUlBasicMeas

MinForUlBasicMeas

ChoiceRprtUnitForDlBasicMeas

TenMsecForDlBasicMeas

MinForDlBasicMeas

RSEPS

TCP

Non-HSDPA power

GBP ChoiceRprtUnitForHsdpaPwrMeas

TenMsecForHsdpaPwrMeas

MinForHsdpaPwrMeas

HS-DSCH PBR ChoiceRprtUnitForHsdpaRateMeas

TenMsecForHsdpaPrvidRateMeas

MinForHsdpaPrvidRateMeas

E-DCH PBR ChoiceRprtUnitForHsupaRateMeas

TenMsecForHsupaPrvidRateMeas

MinForHsupaPrvidRateMeas

3.3 Load Measurement Filtering

3.3.1 Layer 3 Filtering on the NodeB Side

The following figure shows the measurement model at the physical layer that is compliant with 3GPP 25.302.

Figure 3-2 Measurement model at the physical layer

In Figure 3-2:

A is the sampling value of the measurement.

B is the measurement value after layer 1 filtering.

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C is the measurement value after layer 3 filtering.

C' is another measurement value (if any) for measurement evaluation.

D is the reported measurement value.

Layer 1 filtering is not standardized by protocols and it depends on vendor equipment. Layer 3 filtering is standardized. The filtering effect is controlled by a higher layer. The alpha filtering that applies to layer 3 filtering is calculated according to the following formula:

Here:

Fn is the new post-filtering measurement value.

Fn-1 is the last post-filtering measurement value.

Mn is the new measurement value from the physical layer.

α = (1/2)k/2

, k is the measure filter coefficient which is specified by the following parameters.

− For load control algorithms (excluding OLC), k is specified by the UlBasicCommMeasFilterCoeff or DlBasicCommMeasFilterCoeff parameter.

− For OLC algorithm, k is specified by the UlOlcMeasFilterCoeff or DlOlcMeasFilterCoeff parameter.

3.3.2 Smooth Filtering on the RNC Side

After the RNC receives the measurement report, it filters the measurement value through the smooth window method.

Assuming that the reported measurement value is Qn and that the length of the smooth window is N, the filtered measurement value is

LDM must apply different smooth window length and measurement periods to PUC, CAC, LDR, and OLC to obtain appropriate filtered values.

The following table lists the smooth window length parameters for setting different functions.

Function Smooth Window Length Parameter

PUC PucAvgFilterLen

CAC UlCacAvgFilterLen

DlCacAvgFilterLen

LDB LdbAvgFilterLen

LDR UlLdrAvgFilterLen

DlLdrAvgFilterLen

OLC UlOlcAvgFilterLen

DlOlcAvgFilterLen

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GBP measurements have the same smooth window length in all related functions. The filter length for GBP measurement is specified by the HsdpaNeedPwrFilterLen parameter.

The length of the PBR smooth filter window is specified by the HsdpaPrvidBitRateFilterLen / HsupaPrvidBitRateFilterLen parameter.

3.4 Auto-Adaptive Background Noise Update Algorithm

Uplink (UL) background noises are sensitive to environmental conditions, and the fluctuation of the background noises has a negative impact on the RTWP measurement value. Therefore, the LDM function incorporates an auto-adaptive update algorithm to restrict the background noise within a specified range, as described here:

If the temperature in the equipment room is constant, the background noise changes slightly. In this case, the background noise requires no adjustment after initial correction.

If the temperature in the equipment room varies with the ambient temperature, the background noise changes greatly. In this case, the background noise requires auto-adaptive upgrade.

The following figure shows the procedure of auto-adaptive background noise update, which is enabled by the BGNSwitch parameter.

BGNSwitch is set to ON by default.

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Figure 3-3 Procedure of auto-adaptive background noise update

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The Alpha filter formula is: Fn = (1 - α) x Fn-1 + α x Mn (n≥1). For details about this formula, see section 3.3.1 "Layer 3

Filtering on the NodeB Side."

Counting threshold = (Duration of background noise)/(RTWP reporting period). The duration of background noise is used in auto-adaptive upgrade decision and is set by the BGNAdjustTimeLen parameter. For the setting of RTWP reporting period, see section 3.2 "Reporting Period."

The procedure of auto-adaptive background noise update is as follows:

1. The RNC initializes the counter and filter that are used for auto-adaptive upgrade and sets the initial value (F0) of the filter to BackgroundNoise.

2. The RNC receives the latest RTWP measurement value (Mn) from the physical layer.

3. The RNC checks whether the current time is within the effective period of the algorithm, that is, whether the current time is later than BgnStartTime and earlier than BgnEndTime. If the current time is within the effective period, the RNC performs the next step. Otherwise, the RNC waits for the next RTWP measurement value.

4. The RNC determines whether the current Equivalent Number of Users (ENU) in the cell is greater than the value of BGNEqUserNumThd:

− If the current ENU is greater than this threshold value, the RNC infers that Mn includes other noises in addition to the background noise, and therefore it does not feed Mn to the filter. In addition, the RNC sets the counter to zero, retains the current background noise, sets the initial value of the filter to the current background noise, and waits for the next RTWP measurement value.

− If the current ENU in the cell is smaller than or equal to the threshold value, the RNC feeds Mn to the filter and performs the next step.

5. The RNC checks whether |Mn - Fn-1| is smaller than the value of BgnAbnormalThd. If it is smaller than this threshold value, the RNC increments the counter by one, calculates Fn according to the Alpha filter formula, and performs the next step. Otherwise, the RNC waits for the next RTWP measurement value.

6. The RNC checks whether the counter reaches the counting threshold. If it reaches the counting threshold, the RNC performs the next step. Otherwise, the RNC waits for the next RTWP measurement value.

7. The RNC checks whether |Fn - BackgroundNoise| is smaller than the value of BgnAbnormalThd. The purpose is to prevent burst interference and RTWP spike. If it is smaller than the value of BgnAbnormalThd, the RNC performs the next step. Otherwise, the RNC sets the counter to zero and waits for the next RTWP measurement value.

8. The RNC checks whether |Fn - current background noise| is greater than the value of BgnUpdateThd. The purpose is to prevent frequent background noise upgrades on the Iub interface. If it is greater than the value of BgnUpdateThd, the RNC sets the current background noise to Fn, sets the counter to zero, and waits for the next RTWP measurement value. Otherwise, the RNC sets the counter to zero and waits for the next RTWP measurement value.

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Load Control 4 Potential User Control



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4 Potential User Control

This chapter describes the WRFD-020105 Potential User Control feature.

The Potential User Control (PUC) function controls the cell selection and cell reselection of a UE that is in idle mode, in the CELL_FACH state, CELL_PCH state, or URA_PCH state and prevents the UE from camping on a heavily loaded cell.

The PUC is valid only for inter-frequency cells, and it takes effect only in the downlink.

Figure 4-1 shows the PUC procedure.

Figure 4-1 PUC procedure

The PUC function is enabled only when the PUC subparameter of the NBMLdcAlgoSwitch parameter is set to 1.

For a cell not supporting DC-HSDPA, the RNC periodically monitors the downlink load of the cell.

If the cell load is higher than the upper threshold (SpucHeavy) plus the load level division hysteresis (SpucHyst), the cell load is considered heavy.

If the cell load is lower than the lower threshold (SpucLight) minus SpucHyst, the cell load is considered light.

For a cell supporting DC-HSDPA, the RNC concurrently monitors the load state of each single cell and load state of the cell group.

The checking of load state of a single cell is the same as that of a cell not supporting DC-HSDPA.

The checking of load state of the cell group is as follows:

− If the load of the two cells is higher than their upper thresholds (SpucHeavy) plus their load level division hystereses (SpucHyst), the load of the cell group is considered heavy.

− If the load of the two cells is lower than their lower thresholds (SpucLight) minus their load level division hystereses (SpucHyst), the load of the cell group is considered light.

The load state of a cell supporting DC-HSDPA is determined based on the following table.

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Load of Single Cell Load of Cell Group Load of Cell Supporting DC-HSDPA

Heavy Heavy, normal, or light Heavy

Heavy, normal, or light Heavy Heavy

Normal Normal, or light Normal

Normal, or light Normal Normal

Light Light Light

The states of a cell load are heavy, normal, and light, as shown in Figure 4-2.

Figure 4-2 Cell load states

Based on the cell load, the PUC works as follows:

If the cell load becomes heavy, the PUC modifies cell selection and reselection parameters and broadcasts them through system information. In this way, the PUC leads UEs to the neighboring cells with light load.

If the cell load becomes normal, the PUC uses the cell selection and reselection parameters configured on the RNC LMT.

If the cell load becomes light, the PUC modifies cell selection and reselection parameters and broadcasts them through system information. In this way, the PUC leads UEs to this cell.

The variables related to cell selection and reselection are Qoffset1(s,n) (load level offset), Qoffset2(s,n) (load level offset), and Sintersearch (start threshold for inter-frequency cell reselection). The following table describes PUC-related variables and their impacts on UEs.

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Table 4-1 PUC-related variables and their impacts on UEs

Item Description

Implementation The NodeB periodically reports the transmit power of the cell, and the PUC periodically triggers the following activities:

Assessing the cell load level based on the non-HSPA power and HS-DSCH GBP

Setting Sintersearch, Qoffset1(s,n), and Qoffset2(s,n) based on the cell load level

Updating the parameters in system information SIB3 and SIB11

Adjustment Based on the characteristics of inter-frequency cell selection and reselection, the UE makes the corresponding adjustments:

Sintersearch

- When this value is increased by the serving cell, the UE starts inter-frequency cell reselection ahead of schedule.

- When this value is decreased by the serving cell, the UE delays inter-frequency cell reselection.

Qoffset1(s,n): applies to R (reselection) rule with CPICH RSCP

- When this value is increased by the serving cell, the UE has a lower probability of selecting a neighboring cell.

- When this value is decreased by the serving cell, the UE has a higher probability of selecting a neighboring cell.

Qoffset2(s,n): applies to R (reselection) rule with CPICH Ec/I0

- When this value is increased by the serving cell, the UE has a lower probability of selecting a neighboring cell.

- When this value is decreased by the serving cell, the UE has a higher probability of selecting a neighboring cell.

Depending on the load status of the serving cell, the cell reselection parameters Sintersearch are adjusted up or down or kept unchanged. Changes to the variable Sintersearch are carried out as shown in Table 4-2.

Table 4-2 Changes to Sintersearch according to the load state

Load State of the Serving Cell

S'intersearch Change to Sintersearch

Light S'intersearch = Sintersearch + OffSinterLight

Normal S'intersearch = Sintersearch →

Heavy S'intersearch = Sintersearch + OffSinterHeavy

→: indicates that the parameter value remains unchanged.

: indicates that the parameter value increases.

: indicates that the parameter value decreases.

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The configurations of Qoffset1 and Qoffset are related to the load of the serving cell and the load of the neighboring cells. Changes to Qoffset1 and Qoffset2 are carried out as shown in Table 4-3.

Table 4-3 Changes of Qoffset1 and Qoffset2 according to the load state

Load State of the Neighboring Cells

Load State of the Serving Cell

Q'offset1 Change to Qoffset1

Q'offset2 Change to Qoffset2

Light Light Q'offset1 = Qoffset1 → Q'offset2 = Qoffset2 →

Light Normal Q'offset1 = Qoffset1 → Q'offset2 = Qoffset2 →

Light Heavy Q'offset1 = Qoffset1 + OffQoffset1Light

Q'offset2 = Qoffset2 + OffQoffset2Light

Normal Light Q'offset1 = Qoffset1 → Q'offset2 = Qoffset2 →

Normal Normal Q'offset1 = Qoffset1 → Q'offset2 = Qoffset2 →

Normal Heavy Q'offset1 = Qoffset1 + OffQoffset1Light

Q'offset2 = Qoffset2 + OffQoffset2Light

Heavy Light Q'offset1 = Qoffset1 + OffQoffset1Heavy

Q'offset2 = Qoffset2 + OffQoffset2Heavy

Heavy Normal Q'offset1 = Qoffset1 + OffQoffset1Heavy

Q'offset2 = Qoffset2 + OffQoffset2Heavy

Heavy Heavy Q'offset1 = Qoffset1 → Q'offset2 = Qoffset2 →

The prerequisite for the changes of the preceding parameters is that these parameters retain their default values.

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5 Intelligent Access Control

5.1 Overview of Intelligent Access Control

The purpose of IAC is to increase the access success rate, that is, RRC connection success rate and RAB setup success rate.

There are two types of IAC, namely, IAC for RRC connection processing and IAC for RAB connection processing.

IAC for RRC connection processing is used to select a suitable cell for a UE to access through redirection and RRC DRD. It also implements load balancing and service steering.

IAC for RAB connection processing is used to select a suitable cell for a UE to access through DRD and CAC. It also implements load balancing and service steering. Preemption, queuing, and low-rate access are used to further improve the RAB setup success rate.

In addition, IAC provides differentiated services for users with different priorities. For example, when the system resources are insufficient, procedures such as direct admission, preemption, and redirection can be performed to ensure the successful access of emergency calls to the network.

Figure 5-1 shows a typical procedure of service access control.

Figure 5-1 Service access control procedure

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As shown in Figure 5-1, the procedure of service access includes the procedures for RRC connection setup and RAB setup. The successful setup of the RRC connection is one of the prerequisites for the RAB setup.

During the RRC connection processing, the RNC performs the following steps.

1. Performs the RRC redirection based on distance (only for UE-originating AMR services). For details, see section 5.2.2 "RRC Redirection based on Distance". If the RNC decides to obtain UE access from another cell, it sends an RRC connection reject message to the UE; otherwise, the RNC performs the next step.

2. Performs RRC redirection for service steering. For details, see section 5.2.3 "RRC Redirection for Service Steering."

− If the RNC decides to obtain UE access from the current cell, it then makes a resource-based admission decision. If the resource-based admission fails, the RNC performs directed retry decision (DRD) and redirection.

− If the RNC decides to obtain UE access from another cell, it then sends an RRC connection reject message to the UE. The message carries the information about the cell and instructs the UE to set up an RRC connection to the cell.

For details, see5.2 "IAC During RRC Connection Setup."

During the RAB connection processing, the RNC performs the following steps:

1. Performs inter-frequency DRD to select a suitable cell for service steering or load balancing. For details about DRD, see the Directed Retry Decision Feature Parameter Description

2. Performs rate negotiation according to the service requested by the UE. For details, see 5.4 "Rate Negotiation."

3. Makes cell resource-based admission decision. If the admission is successful, UE access is granted. Otherwise, the RNC performs the next step. For details about admission decision, see the Call Admission Control Feature Parameter Description.

4. Selects a suitable cell, according to the inter-frequency DRD, from the cells where no admission attempt has been made, and then go to 2. If all the attempt fails, the RNC performs the next step.

5. Selects a suitable cell according to the inter-RAT DRD. If the inter-RAT admission is successful, UE access is granted in the inter-RAT cell. If the inter-RAT DRD fails or is not supported, the RNC performs the next step.

6. Makes a preemption attempt. For details about preemption, see 5.6 "Preemption" If the preemption is successful, UE access is granted. If the preemption fails or is not supported, the RNC performs the next step.

7. Makes a queuing attempt. For details about queuing, see 5.7 "Queuing." If the queuing is successful, UE access is granted. If the queuing fails or is not supported, the RNC performs the next step.

8. Performs low-rate access. For details about low-rate access, see 5.8 "Low-Rate Access of the PS BE Service." If the low-rate access is admitted, UE access is granted. If the low-rate access is unsuccessful, the RNC performs the next step.

9. Rejects UE access.

After the admission attempts of an HSPA service request fail in all candidate cells, the service falls back to the DCH. Then, the service reattempts to access the network.




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Table 5-1 IAC procedure supported by services

Service Type

Low-Rate Access

Rate Negotiation Preemption Queuing DRD

MB

R

Neg

oti

ati

on

GB

R

Neg

oti

ati

on

Init

ial

Ra

te

Neg

oti

ati

on

Ta

rget

Rate

Neg

oti

ati

on

Inte

r-

Fre

qu

en

cy

Inte

r-R

AT

DCH √ √ √ √ √ √ √ √ √

HSUPA - √ √ √ √ √ √ √ -

HSDPA - √ √ - - √ √ √ -

5.2 IAC During RRC Connection Setup

5.2.1 Procedure of IAC During RRC Connection Setup

Before a new service is admitted to the network, an RRC connection must be set up.

As shown in Figure 5-2, when the switch DrSwitch: DR_RRC_DRD_SWITCH is set to ON, the RRC connection setup procedure is performed as follows.

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Figure 5-2 RRC connection setup procedure

.

After receiving an RRC CONNECTION REQUEST message from the UE, the RNC performs the RRC redirection based on distance (only for UE-originating AMR services). For details, see section 5.2.2 "RRC Redirection based on Distance". If the RNC decides to obtain UE access from another cell, it sends an RRC connection reject message to the UE; otherwise, the RNC performs the next step.

Then, the RNC uses the RRC redirection algorithm for service steering to decide whether the UE can access the network from the current cell:

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If the UE can access the network from the current cell according to the decision result, the RNC uses the CAC algorithm to decide whether an RRC connection can be set up between the UE and the current cell.

− If the RRC connection can be set up between the UE and the current cell, the RNC sends an RRC CONNECTION SETUP message to the UE.

− If the RRC connection cannot be set up between the UE and the current cell, the RNC attempts to select a cell for RRC connection setup through RRC DRD. If the RRC DRD fails, RRC redirection will be performed.

If the UE needs to access the network from another cell according to the decision result, the RNC sends an RRC CONNECTION REJECT message to the UE. The message carries the information about this cell.

DrSwitch: DR_RRC_DRD_SWITCH is the general switch of the following four algorithms:

RRC Redirection based on Distance

RRC Redirection for Service Steering

RRC DRD

RRC Redirection After DRD Failure

Before enabling the four algorithms, turn on the DrSwitch: DR_RRC_DRD_SWITCH.

5.2.2 RRC Redirection based on Distance

This section describes the WRFD-020401 Inter-RAT Redirection Based on Distance feature.

In actual situations, a UE may receive signals from a distant cell and subsequently access the cell. However, the cells that are adjacent to this cell are not configured as its neighboring cells. If the UE moves out of this cell, call drops may occur. To solve this problem, RRC redirection based on distance is introduced.

The RRC redirection based on distance technique estimates the distance between the UE and the cell center by considering the propagation delay. Based on the estimation result, the RNC checks whether to perform RRC redirection. The propagation delay is the one-way propagation delay of the radio signal from the UE to the NodeB. The NodeB measures the propagation delay and then reports it to the RNC. The propagation delay is directly proportional to the distance between the UE and the NodeB.

The switch of RRC redirection based on distance can be set through the RedirSwitch parameter. RRC redirection based on distance is applicable only to the UE-originating AMR services.

The procedure of RRC redirection based on distance is as follows:

1. Upon receiving an RRC CONNECTION REQUEST message from the UE, the RNC checks whether the requested service is the UE-originating AMR service. If yes, the RNC performs the next step. If no, the RNC does not perform RRC redirection based on distance, and handles the RRC connection setup request of the UE in the current cell.

2. The RNC obtains the propagation delay from the NodeB and compares it with DelayThs.

− If the propagation delay is greater than DelayThs, the RNC performs the next step.

− If the propagation delay is equal to or less than DelayThs, the RNC does not perform RRC redirection based on distance, and handles the RRC connection setup request of the UE in the current cell.

3. The RNC checks the load status of the current cell and checks whether to perform RRC redirection based on distance by considering the load status.

− If the cell is in the normal state, the RNC generates a random value ranging from 0 to 1 and compares the value with the RedirFactorOfNorm parameter. If the random value is equal to or

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smaller than the parameter, the RNC performs the next step. Otherwise, the RNC does not perform RRC redirection based on distance, and handles the RRC connection setup request of the UE in the current cell.

− If the cell is in the basic congestion state or is overloaded, the RNC generates a random value ranging from 0 to 1 and compares the value with the RedirFactorOfLDR parameter. If the random value is equal to or smaller than the parameter, the RNC performs the next step. Otherwise, the RNC does not perform RRC redirection based on distance, and handles the RRC connection setup request of the UE in the current cell.

4. The RNC sends the UE an RRC CONNECTION REJECT message containing information on the neighboring GSM cells of the current cell.

If the current cell does not have any neighboring GSM cell, the UE spontaneously selects a proper cell to access.

5.2.3 RRC Redirection for Service Steering

Overview

This section describes the WRFD-020120 Service Steering and Load Sharing in RRC Connection Setup feature.

The purpose of RRC redirection for service steering is to enable the successful RRC connection setup by selecting an appropriate cell for the UE based on the requested service. This algorithm is not applicable to combined services.

During the RRC connection setup, the RNC implements service steering between inter-frequency or inter-RAT cells according to the service type requested by the UE. In addition, the RNC considers the load of the cell for access and the redirection factors to control the degree of load sharing. Therefore, this function also can also be called service steering and load sharing in RRC connection setup.

Procedure of RRC Redirection for Service Steering

The procedure of RRC redirection for service steering is as follows:

1. The RNC obtains the information about the service requested by the UE and the capability of the UE.

− If the DR_ RRC_DRD_SWITCH is set to 1, the RNC determines the service type requested by the UE. If the RNC succeeds in determining the service type requested by the UE and the switch of RRC direction for service steering (RedirSwitch) is set to ONLY_TO_INTER_FREQUENCY or ONLY_TO_INTER_RAT, the RNC performs the next step. Otherwise, the RNC handles the RRC connection setup request of the UE in the current cell.

− If the DR_ RRC_DRD_SWITCH is set to 0, the RNC handles the RRC connection setup request of the UE in the current cell.

2. Based on the cell load and the redirection factors, the RNC decides whether to perform RRC redirection for service steering.

− If the cell is in the normal state, the RNC generates a random number between 0 and 1 and compares it with the corresponding unconditional redirection factor (RedirFactorOfNorm). If the random number is smaller than this factor, the RNC performs the next step. Otherwise, the RNC handles the RRC connection setup request of the UE in the current cell.

− If the cell is in the basic congestion or overload state, the RNC generates a random number between 0 and 1 and compares it with the value of RedirFactorOfLDR. If the random number is smaller than this factor, the RNC performs the next step. Otherwise, the RNC handles the RRC connection setup request of the UE in the current cell.

3. Based on the setting of RedirSwitch, the RNC takes the corresponding actions:

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− If RedirSwitch is set to ONLY_TO_INTER_FREQUENCY, the RNC sends an RRC CONNECTION REJECT message to the UE, redirecting the UE to the target frequency carried in the message.

The frequency information carried in the message can be set by running the SET UREDIRECTION command.

If the RedirBandInd parameter is set to DependOnNCell, only intra-band inter-frequency neighboring cell can be selected as target frequency.

− If RedirSwitch is set to ONLY_TO_INTER_RAT, the RNC sends an RRC CONNECTION REJECT message to the UE. The message carries the information about inter-RAT neighboring cells.

Service Identification Rule

The RNC identifies requested services according to the relevant information elements (IEs) in the RRC CONNECTION REQUEST message received from the UE. The identification is successful only when all the conditions described in Table 5-2 are met. Otherwise, the identification fails.

Table 5-2 Service identification rule

Identified Service Type

Reference IE

Establishment cause Domain indicator

Call type UE capability indication

Access stratum release indicator

AMR Originating Conversational Call CS domain Speech N/A REL-6

REL-7

AMR Originating Conversational Call N/A N/A N/A R99

REL-4

REL-5

VP Originating Conversational Call CS domain Video N/A REL-6

REL-7

PS R99 Originating Interactive Call

Originating Background Call

N/A N/A N/A R99

REL-4

PS R99 Originating Interactive Call


PS domain N/A Not HS-DSCH or HS-DSCH +E-DCH

REL-6

REL-7

PS HSPA Originating Interactive Call


PS domain N/A HS-DSCH or HS-DSCH +E-DCH

REL-6

REL-7

PS R99 and PS HSPA services for UEs of the REL-5 version cannot be identified by the RNC because these UEs do

not carry the Domain indicator, Call type, or UE capability indication IEs in the RRC CONNECTION REQUEST message.

In order to reduce the waiting time of the peer UE and ensure that the terminated call can be admitted as soon as possible, the RRC redirection based on service steering is not applicable to the terminated call.

5.2.4 RRC DRD

If the UE fails to access the current cell, the RNC performs RRC DRD. The purpose is to instruct the UE to set up an RRC connection in an inter-frequency neighboring cell with better signal quality.

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The RNC performs the following steps:

1. The RNC selects the intra-band inter-frequency neighboring cells of the current cell. These neighboring cells are suitable for blind handovers. Whether the neighboring cells support blind handover is specified by the parameter BlindHoFlag.

2. The RNC generates a list of candidate DRD-supportive inter-frequency cells according to the following condition:

(CPICH_EcNo)RACH > DRD_EcNOnbcell

Here:

− (CPICH_EcNo)RACH is the cached CPICH Ec/N0 value included in the RACH measurement report. Note that this value is of the current cell.

− DRD_EcNOnbcell is the DRD threshold (DRDEcN0Threshhold) of the neighboring cell.

3. The RNC selects a target cell from the candidate cells for UE access. If the candidate cell list is empty, the RRC DRD fails. The RNC performs RRC redirection. If the candidate cell list contains more than one cell, the UE tries a cell randomly.

− If the admission is successful, the RNC continues the RRC connection setup procedure.

− If the admission to a cell fails, the UE tries admission to another cell in the candidate cell list until an admission is successful or all admission attempts fail.

− If all the admission attempts fail, the RNC makes an RRC redirection decision.

5.2.5 RRC Redirection After DRD Failure

This section describes the WRFD-02040003 Inter System Redirect feature.

The purpose of RRC redirection after DRD failure is to instruct the UE to set up RRC connection in an inter-frequency or an inter-RAT cell.

When the RRC DRD fails, the RNC performs RRC redirection as follows:

The RNC selects another frequency for redirection based on the setting of the ReDirBandInd parameter. If the ReDirBandInd parameter is set to a specific band, the RNC selects the configured target frequency number and redirects the UE. The target frequency number is configured by the following parameters: ReDirUARFCNUplinkInd, ReDirUARFCNUplink, ReDirUARFCNDownlink2.

If the ReDirBandInd parameter is set to DependOnNCell, the RNC selects the target frequency number from the target frequency numbers corresponding to the intra-band inter-frequency neighboring cells of the current cell. In addition, the RNC excludes the target frequency numbers corresponding to the cells that have carried out inter-frequency RRC DRD attempts.

If more than one target frequency number is available, the RNC selects a target frequency number randomly. Then, the RNC sent an RRC CONNECTION REJECT message to the UE, redirecting the UE to the selected target frequency carried in the message.

If no target frequency number is available, the RNC continues to perform RRC redirection according to the setting of the ConnectFailRrcRedirSwitch parameter.

− If ConnectFailRrcRedirSwitch is set to Only_To_Inter_Frequency, the RRC connection setup fails.

− If ConnectFailRrcRedirSwitch is set to Allowed_To_Inter_RAT and there is a neighboring GSM cell, the RNC sends the information about the neighboring GSM cell to the UE and redirects the UE to GSM system. If ConnectFailRrcRedirSwitch is set to Allowed_To_Inter_RAT but there is no neighboring GSM cell, the UE automatically searches for GSM cells and then selects one of them for RRC connection setup attempts.

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5.3 Directed Retry Decision

Traffic steering and load sharing during RAB setup will be performed through Directed Retry Decision (DRD).

During the RAB connection processing, non-periodic DRD is used to select a suitable cell for a UE to access according to the HSPA+ technological satisfaction, service priority, and cell load. Non-periodic DRD is performed during RAB setup, RAB modification, or DCCC channel reconfiguration.

Non-periodic DRD involves inter-frequency DRD and inter-RAT DRD.

By using inter-frequency DRD, the RNC selects the qualified candidate cells by considering HSPA+ technological satisfaction, cell service priority, and cell load. Then, the RNC sequences the candidate cells according to the priority. According to the sequence from the highest to the lowest, the UE tries accessing the cells until it is admitted or it fails to access any cell.

If the UE fails to access any cell in the case of inter-frequency DRD, inter-RAT DRD will be triggered.

For details about non-periodic DRD, see the Directed Retry Decision Feature Parameter Description.

5.4 Rate Negotiation at Admission Control

Rate negotiation at admission control (WRFD-010507 Rate Negotiation at Admission Control) includes MBR negotiation, GBR negotiation, initial rate negotiation, and target rate negotiation.

For a streaming service, the RNC performs resource admission based on the negotiated MBR.

For a new PS BE service, the RNC performs resource admission based on the negotiated initial rate.

For AMR and AMR-WB speech services in the CS domain, see the AMR Feature Parameter Description.

5.4.1 PS MBR Negotiation

If the IE "Alternative RAB Parameter Values" is present in the RANAP RAB ASSIGNMENT REQUEST or the RELOCATION REQUEST message when a PS service is set up, reconfigured, or handed over, then the RNC and the CN negotiate the rate according to the UE capability to obtain the MBR while ensuring a proper QoS.

For the PS streaming service, when PS_STREAM_IU_QOS_NEG_SWITCH subparameter of the PsSwitch parameter is set to 1, the Iu QoS negotiation function is enabled for MBR negotiation.

For the PS BE service:

− When both PS_BE_IU_QOS_NEG_SWITCH and PS_BE_STRICT_IU_QOS_NEG_SWITCH subparameters of the PsSwitch parameter are set to 1, the Iu QoS negotiation function is enabled, and the RNC determines the MBR of Iu QoS negotiation based on the information about UE capability, cell capability and rate requested by the CN.

− When PS_BE_IU_QOS_NEG_SWITCH is set to 1 and PS_BE_STRICT_IU_QOS_NEG_SWITCH is set to 0, the Iu QoS negotiation function is enabled, and the RNC determines the MBR of Iu QoS negotiation based on the maximum rate supported by the UE rather than the cell capability and other settings.

5.4.2 PS GBR Negotiation

During the setup, reconfiguration, or handover of a PS real-time service, if the subparameter PS_STREAM_IU_QOS_NEG_SWITCH of the parameter PsSwitch is set to 1, the RNC will negotiate with the CN about the GBR as follows:

If the IE "Type of Alternative Guaranteed Bit Rate Information" in the RAB ASSIGNMENT REQUEST message is set to "unspecified", the GBR negotiation will not be performed. In such a case, the GBR


AMR.htm

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contained in the IE "RAB Parameters" of the RAB ASSIGNMENT REQUEST message is used. In addition, the subsequent RAB ASSIGNMENT RESPONSE message does not contain the GBR.

If the IE "Type of Alternative Guaranteed Bit Rate Information" in the RAB ASSIGNMENT REQUEST message is set to "value range", the sole GBR contained in the IE "Alternative Guaranteed Bit Rates" is used. In addition, the subsequent RAB ASSIGNMENT RESPONSE message contains the GBR.

If the IE "Type of Alternative Guaranteed Bit Rate Information" in the RAB ASSIGNMENT REQUEST message is set to "Discrete values", the largest GBR contained in the IE "Alternative Guaranteed Bit Rates" is used. In addition, the subsequent RAB ASSIGNMENT RESPONSE message contains the GBR.

If the subparameter PS_STREAM_IU_QOS_NEG_SWITCH of the parameter PsSwitch is set to 0, the GBR negotiation will be not performed. In such a case, the GBR contained in the IE "RAB Parameters" in the RAB ASSIGNMENT REQUEST message is used.

For details about GBR negotiation, see 3GPP 25.413.

5.4.3 Initial Rate Negotiation

Overview

Initial rate is classified into initial admission rate and initial access rate.

Initial admission rate: The RNC allocates bandwidths based on the initial admission rate and then performs cell-resource-based admission based on the allocated bandwidths.

Initial access rate: Initial configured rate after service admission is successful, which means the current maximum data transmission rate before any other reconfiguration.

For PS BE services, the RNC performs initial rate negotiation when a new service is being set up or the UE is changing from the CELL_FACH state to CELL_DCH. The initial rate negotiation policy varies, depending on the services carried on different channels.

Initial Rate Definition for DCH Services

For DCH services, the initial admission rate and the initial access rate are the same.

Initial rate is negotiated according to the following table:

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DCCC Switch (DCCC_SWITCH)

PS BE Initial Rate Dynamic Configuration Switch (PS_BE_INIT_RATE_DYNAMIC_CFG_SWITCH)

Actual Initial Rate

ON ON In the uplink, the initial rate is the smaller one of the MBR and 384 kbit/s.

In the downlink, the initial rate is dynamically set on the basis of Ec/N0. The specific method is as follows:

When receiving an RRC connection setup request, the RNC starts the timer EcN0EffectTime.

Before the timer expires, the RNC dynamically sets the initial rate based on the Ec/N0. The value of Ec/N0 comes from the latest RACH measurement report or latest intra-frequency measurement report.

If the cell Ec/N0 reported from the UE is above the Ec/N0 threshold (EcN0Ths), the RNC sets the actual initial rate to the smaller one of the MBR and 384 kbit/s.

Note that if the UE is in the soft handover state, the RNC sets the actual initial rate to the smaller one of the MBR and 384 kbit/s when any of the cells in the active set meets the threshold.

If the cell Ec/N0 is below or equal to the Ec/N0 threshold (EcN0Ths) or the RRC CONNECTION REQUEST message does not carry the information about Ec/N0, the RNC sets the actual initial rate to the smaller one of the MBR and the initial rate of the downlink BE service (DlBeTraffInitBitrate).

ON OFF In the uplink, the initial rate is the smaller one of the MBR and the initial rate of the uplink BE service (UlBeTraffInitBitrate).

In the downlink, the initial rate is the smaller one of the MBR and the initial rate of the downlink BE service (DlBeTraffInitBitrate).

OFF - MBR

If the DCCC function is enabled and PS_RAB_Downsizing_Switch subparameter of the PsSwitch parameter is set to 1, the RNC can decrease the rate through the RAB rate decrease function when the admission based on the initial rate fails.

Initial Rate Definition for HSPA Services

For the HSUPA service,

The initial admission rate is GBR.

The initial access rate is defined as follows:

− If the DRA_HSUPA_DCCC_SWITCH subparameter of the DraSwitch parameter is set to 1, the actual initial access rate is the initial rate of the HSUPA BE service (HsupaInitialRate).

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− If the DRA_HSUPA_DCCC_SWITCH subparameter of the DraSwitch parameter is set to 0, the

initial access rate is the MBR for there won't be any rate upsizing reconfiguration when the DRA_HSUPA_DCCC_SWITCH subparameter of the DraSwitch parameter is set to 0.

For the HSDPA service, the initial admission rate and the initial access are both GBR.

5.4.4 Target Rate Negotiation

For a BE service in the PS domain, if the cell resource-based admission at the initial rate fails, the RNC selects a target rate to allocate bandwidth for the service based on cell resource in following cases:

Service setup

Soft handover

DCCC rate upsizing

If the cell has sufficient code and CE resources, the RNC sets the candidate target rate to the one that matches the cell resource surplus. Then, the RNC sets the target rate to the greater one of the candidate target rate and the GBR.

In the case of DCCC rate upsizing, if the rate upsizing fails, the target rate is the greater one of the candidate target rate and the pre-upsizing DCCC rate.

5.5 Admission Decision

A radio link sends a resource request to the CAC functional module when additional resources are required. On receipt of the resource request, the CAC functional module determines whether the request can be accepted by measuring the cell load and the request resources.

The admission decision performed by CAC is based on resources, such as code resources, power resources, NodeB credits, and Iub resources. In the case of HSPA resource request, the admission decision is also based on the number of HSPA users. The admission succeeds only when the resources on which CAC is based are available.

For details about CAC, see the Call Admission Control Feature Parameter Description.

5.6 Preemption

5.6.1 Common Preemption

This section describes the pre-emption algorithm in the WRFD-010505 Queuing and Pre-Emption feature.

By forcibly releasing the resources of lower-priority users, the preemption (pre-emption) function increases the access success rate of higher-priority users.

After cell/cell group resource-based admission fails, the RNC performs preemption if the following conditions are met:

The RNC receives a RAB ASSIGNMENT REQUEST message indicating that preemption is supported.

In the RAB ASSIGNMENT REQUEST message sent by the CN, the Pre-emption Capability IE specifies whether a service can trigger preemption and the Pre-emption Vulnerability IE specifies whether a service can be preempted. Service priorities and the Pre-emption Capability and Pre-emption Vulnerability IEs determine whether to perform preemption.

The preemption algorithm switch (PreemptAlgoSwitch) is set to ON.

Preemption is applicable to the following scenarios:


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Setup or modification of a service

Hard handover or SRNS relocation

UE state transition from CELL_FACH to CELL_DCH

The procedure of preemption is as follows:

1. The RNC selects the target cell for preemption. For DC-HSDPA services, the RNC selects the primary cell in the DC-HSDPA cell group as the target cell. For non-DC-HSDPA services, the RNC selects a suitable cell with higher service priority or lower load.

2. The preemption algorithm determines the radio link sets to be preempted.

a. Selects SRNC users first. If no user under the SRNC is available, the algorithm selects users under the DRNC.

b. Sorts the preemptable users by user integrated priority, or sorts the preemptable RABs by RAB integrated priority.

c. Determines candidate users or RABs.

For RABs of streaming or BE services, if PriorityReference is set to Traffic Class and PreemptRefArpSwitch is set to ON, only the ones with lower priority than the RAB to be established are selected.

Selects as many users or RABs as necessary in order to match the resource needed by the RAB to be established. When the priorities of two users or RABs are the same, the algorithm selects the user or RAB that can release the most resources.

Preemptable users or RABs must have lower priories than RABs to be established. The type of preemptable user or RAB varies, depending on the type of resource that triggers the preemption.

The preemption algorithm checks whether the resources released by preempted UEs or RABs are sufficient for setting

up new RABs. It does not consider the remaining resources in the cell, because they may be used by other UEs during the preemption.

For the preemption triggered for power, the preempted objects can be R99 users, R99 + HSPA combined users, or HSPA RABs.

For the preemption triggered for the Iub bandwidth, the preempted objects can only be RABs.

For the preemption triggered for the credit resource, more than one user or RAB can be preempted.

For the preemption triggered for the code, only one user can be preempted.

3. The RNC releases the resources occupied by the candidate users or RABs.

4. The requested service directly uses the released resources to access the network without admission decision.

For details about preemption of MBMS services, see the MBMS Feature Parameter Description.

5.6.2 Forced Preemption

Common preemption requires that RABs have been set up or are being set up for preempting users and that preempting users have higher priorities than preemptable users. Therefore, CS services cannot trigger preemption in the RRC connection setup phase. Even in the RAB-related phases, CS services may fail to preempt PS services because of insufficient priorities. When PS traffic volume is high and radio resources are insufficient, the success rate for CS service setup may decrease. To address this problem, forced preemption is introduced. This function ensures preferred access of AMR services and a high success rate for AMR service setup.

In forced preemption, only CS conversational services can trigger preemption and only PS BE services can be preempted.

MBMS.htm

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This function is determined by the RsvdPara1 parameter. This parameter consists of two subparameters: RSVDBIT4 and RSVDBIT5.

Table 5-3 describes how these two subparameters determine preemption.

Table 5-3 Forced preemption

RsvdPara1: RSVDBIT5

RsvdPara1: RSVDBIT4

RRC Connection Setup Phase RAB-Related Phases

On Off CS conversational services cannot preempt PS BE services.

If RAB admission for CS conversational services fails, PS BE services can be preempted unconditionally.

On On If RRC admission for CS conversational services fails, PS BE services can be preempted unconditionally.

If RAB admission for CS conversational services fails, PS BE services can be preempted unconditionally.

Off On If RRC admission for CS conversational services fails, PS BE services whose Pre-emption Vulnerability IE is set to "pre-emptable" can be preempted.

Common preemption is performed. That is, service priorities and the Pre-emption Capability and Pre-emption Vulnerability IEs determine whether to perform preemption.

Off Off CS conversational services cannot preempt PS BE services.

Common preemption is performed. That is, service priorities and the Pre-emption Capability and Pre-emption Vulnerability IEs determine whether to perform preemption.

In the RRC connection setup phase, if an RRC setup request is from the CS domain and the cause of RRC setup is Originating Conversational Call or Terminating Conversational Call, the RNC regards the corresponding service as CS conversational service.

In the case of unconditional preemption, the RNC does not compare the priority of CS conversational services with that of PS BE services. In addition, it does not consider the Pre-emption Capability or Pre-emption Vulnerability IE delivered by the CN. In this case, PS BE services can be preempted by any CS conversational services and only PS BE services can be preempted. Preempted PS BE services are ranked by priority and PS BE services with the lowest priority are preempted.

5.7 Queuing

This section describes the queuing algorithm in the WRFD-010505 Queuing and Pre-Emption feature.

For PS services, after preemption fails, the RNC performs queuing if the following conditions are met:

The RNC receives a RAB ASSIGNMENT REQUEST message indicating that queuing is supported.

The queuing algorithm switch (QueueAlgoSwitch) is set to ON.

The queuing function is triggered by the heartbeat timer that is set by the PollTimerLen parameter. Each time the timer expires, the RNC selects the service that meets the requirement to make an admission attempt.

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The UE requesting DC-HSDPA services will be queued in the selected anchor-carrier cell.

The queuing function performs the following functions:

The queuing algorithm checks whether the queue is full, that is, whether the number of service requests in the queue exceeds QueueLen.

The queuing algorithm decides whether to put the request into the queue, as described in the following table.

Table 5-4 Putting the new request into the queue

If the queue is... Then the queuing algorithm...

Not full Stamps this request with the request time (T_request)

Puts this request into the queue

Starts the heartbeat timer if it is not started

Full Checks whether the integrated priority of any existing request is lower than that of the new request

If yes, then the queuing algorithm:

- Checks the queuing time of each request. The algorithm removes the request with the longest queuing time from the queue

- Stamps the new request with the request time (T_request) and then puts it into the queue

- Starts the heartbeat timer if it is not started

If no, then the queuing algorithm rejects the new request directly

After the heartbeat timer expires, the queuing algorithm performs resource-based admission attempts as follows:

Rejects the request if the queuing time of the request(Telapsed ) is longer than the maximum queuing time (MaxQueueTimeLen). Here, Telapsed is equal to the current time minus the request time (T_request).

Selects the request with the highest integrated priority for a resource-based admission attempt.

If more than one service has the highest integrated priority, the RNC selects the request with the longest queuing time.

If the attempt is successful, the heartbeat timer is restarted for the next processing.

If the attempt fails, the queuing algorithm proceeds as follows:

− Puts the service request back into the queue with the request time (T_request) unchanged for the next attempt.

− Selects the request with the longest queuing time from the rest and makes another attempt until a request is accepted or all requests are rejected.

5.8 Low-Rate Access of the PS BE Service

If the PS_BE_EXTRA_LOW_RATE_ACCESS_SWITCH subparameter of the PsSwitch parameter is set to 1, to increase the access success rate, the PS BE service can access the target cell at a low rate in the case of a preemption or queuing failure. Low-rate access means access from the DCH at 0 kbit/s, FACH, or enhanced FACH (E-FACH).

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Low-rate access is used in the following scenarios:

RAB setup

Hard handover or SRNS relocation

After a service request is rejected, the low-rate access actions in different scenarios are as follows:

Scenario Scenario Description FACH/E_FACH DCH at 0 kbit/s

RAB setup The RRC connection is set up on the FACH or E-FACH.

√ ×

The RRC connection is set up on the DCH. × √

The RRC connection is set up on the HSPA channel.

× √

The CS service is set up, and a new PS service is to be set up.

× √

The existing PS service is set up on the FACH/E-FACH, and a new PS service is to be set up.

√ ×

The existing PS service is set up on the DCH, and a new PS service is to be set up.

× √

The existing PS service is set up on the HSPA channel, and a new PS service is to be set up.

× √ (the new PS service can be admitted at 0 kbit/s)

The PS service is set up, and a new CS service is to be set up.

× ×

Hard handover or relocation

Hard handover or relocation is performed for the CS+PS combined services.

× √ (only the PS service can be admitted at 0 kbit/s)

Hard handover or relocation is performed for the PS+PS combined services.

× √

After an appropriate access action is determined, the service attempts to access the network.

If the action of access from the DCH at 0 kbit/s is determined, the service attempts to access the network at 0 kbit/s for traffic and at the normal rate for signaling. For details about the methods of resource-based admission decision, see the Call Admission Control Feature Parameter Description.

If the action of access from the FACH/E-FACH is determined, the service attempts to access the network from the FACH/E-FACH.

If the attempt fails, this service is rejected.

For the service that accesses the network at 0 kbit/s, the ZeroRateUpFailToRelTimerLen timer is started after the service rate fails to increase for the first time. If the rate fails to increase even when the timer expires, the service is released, and the connection is also released for a single service.

If no data is transmitted during a period after the access, the UE state changes to another state. For details about state transition, see the State Transition Feature Parameter Description.


State%20Transition.htm

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5-17

5.9 IAC for Emergency Calls

This section describes the WRFD-021104 Emergency Call feature.

To guarantee successful access of emergency calls, the RNC takes special measures for emergency calls.

5.9.1 RRC Connection Setup Process of Emergency Calls

Compared with the RRC connection setup process of common services, the RRC connection setup process of emergency calls incorporates the preemption due to hard resource-based admission failure. Hard resources include code, Iub, and CE resources. The following figure shows the RRC connection setup process of an emergency call.

Figure 5-3 RRC connection setup process of an emergency call

The RNC does not perform RRC redirection for service steering.

In the case of power-based admission, the emergency call is admitted regardless of whether the CAC function is enabled or not.

In the case of hard resource-based admission, the emergency call is admitted if the current remaining resources are sufficient for RRC connection setup. If the admission fails, preemption is performed regardless of whether the preemption is enabled or not. The emergency call that triggers preemption has the highest priority. The range of users who can be preempted is specified by the EmcPreeRefVulnSwitch parameter.

If EmcPreeRefVulnSwitch is set to ON, all non-emergency users who have accessed the network can be preempted, regardless of the preemption-prohibited attribute of the users.

If EmcPreeRefVulnSwitch is set to OFF, only the non-emergency users with preemption-allowed attribute can be preempted.

The principles for selection of specific users to be preempted are the same as those for common services. For details, see 5.6 "Preemption."

5.9.2 RAB Process of Emergency Calls

Compared with the RAB process of common services, the RAB process of emergency calls incorporates special processing of resource-based admission and preemption.

RAB Admission of Emergency Calls

In case of power resources:

If the CAC function is enabled, regardless of which algorithm is selected, the admission decision is made as follows:

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− When the EMC_UU_ADCTRL subparameter of the NBMCacAlgoSwitch parameter is set to 1, power-based admission fails if the system is in the overload congestion state. Otherwise, the admission succeeds.

− When this subparameter is set to 0, the emergency calls are directly admitted.

If the CAC function switch is off, the emergency calls are directly admitted.

For hard resources (that is, code, Iub, and CE), the resource-based admission is successful if the current remaining resources are sufficient for the request.

Preemption of Emergency Calls

If cell resource-based admission fails, preemption is performed regardless of whether the preempt function is enabled or not. The emergency calls that trigger preemption have the highest priority. The range of users who can be preempted is specified by the EmcPreeRefVulnSwitch parameter.

If EmcPreeRefVulnSwitch is set to ON, all non-emergency users who have accessed the network can be preempted, regardless of the preemption-prohibited attribute of the users.

If EmcPreeRefVulnSwitch is set to OFF, only the non-emergency users with preemption-allowed attribute can be preempted.

The principles for selection of specific users to be preempted are the same as those for common services. For details, see 5.6 "Preemption."

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Load Control 6 Intra-Frequency Load Balancing



6-1

6 Intra-Frequency Load Balancing

This chapter describes the WRFD-020104 Intra-Frequency Load Balance feature.

Intra-frequency Load Balancing (LDB) is performed to adjust the coverage areas of cells according to the measured values of cell load. The intra-frequency LDB function is applicable only to the downlink.

LDB between intra-frequency cells is implemented by adjusting the transmit power of the Primary Common Pilot Channel (P-CPICH) according to the downlink load of the associated cells. When the load of a cell increases, the cell reduces its coverage to lighten its load. When the load of a cell decreases, the cell extends its coverage so that some traffic is off-loaded from the neighboring cells to it.

When the intra-frequency LDB function is active, that is, when the INTRA_FREQUENCY_LDB subparameter of the NBMLdcAlgoSwitch parameter is set to 1, the RNC checks the load of cells periodically and adjusts the transmit power of the P-CPICH in the associated cells based on the cell load.

The following figure shows the procedure of intra-frequency LDB.

Figure 6-1 Procedure of intra-frequency LDB

The intra-frequency LDB is described as follows:

If the downlink load of a cell is higher than the cell overload threshold (CellOverrunThd), it is an indication that the cell is heavily overloaded. In this case, the transmit power of the P-CPICH needs to be reduced step by step. The step is specified by the PCPICHPowerPace parameter.

If the current transmit power is equal to the minimum transmit power of P-CPICH (MinPCPICHPower), the current transmit power is not adjusted.

Because of the reduction in the pilot power, the UEs at the edge of the cell can be handed over to neighboring cells, especially to those with a relatively light load and with relatively high pilot power. After that, the downlink load of the cell is lightened accordingly.

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Load Control 6 Intra-Frequency Load Balancing



6-2

If the downlink load of a cell is lower than the cell underload threshold (CellUnderrunThd), it is an indication that the cell has sufficient remaining capacity for more load. In this case, the transmit power of the P-CPICH can be increased step by step to help lighten the load of neighboring cells. The step is specified by the PCPICHPowerPace parameter.

If the current transmit power is equal to the maximum transmit power of P-CPICH ( ), the current transmit power is not adjusted.

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Load Control 7 Load Reshuffling



7-1

7 Load Reshuffling

This chapter describes the WRFD-020106 Load Reshuffling feature.

When the usage of cell resource exceeds the basic congestion triggering threshold, the cell enters the basic congestion state. In this case, Load Reshuffling (LDR) is required to reduce the cell load and increase the access success rate.

7.1 Basic Congestion Triggering

The basic congestion of a cell is caused by insufficient power resource, code resource, Iub resource, or NodeB credit resource.

For power resource, the RNC performs periodic measurement and checks whether the cells are congested. For code, Iub, and NodeB credit resources, the RNC checks whether the cells are congested when resource usage changes.

If the congestion of all resources is triggered in a cell, the basic congestion triggered by different resource will be relieved in order of resource priority for load reshuffling as configured by running the SET ULDCALGOPARA command.

7.1.1 Power Resource

Congestion control based on power resource can be enabled through the DL_UU_LDR and UL_UU_LDR subparameters of the NBMLdcAlgoSwitch parameter.

If the parameter NBMUlCacAlgoSelSwitch / NBMDlCacAlgoSelSwitch is set to ALGORITHM_SECOND, the load reshuffling algorithm will trigger basic congestion based on Equivalent Number of Users (ENU).

The following figure shows the triggering and relieving of basic congestion.

Figure 7-1 Triggering and relieving of basic congestion

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7-2

As shown in Figure 7-1, if the UL/DL load of the cell is higher than or equal to the UL/DL LDR trigger threshold (UlLdrTrigThd or DlLdrTrigThd) for a hysteresis time, the cell is in the basic congestion state, and the related load reshuffling actions, as listed in Table 7-2, are taken. If the current UL/DL load of the cell is lower than the UL/DL LDR relief threshold (UlLdrRelThd or DlLdrRelThd) for a hysteresis time, the cell backs to the normal state and the related load reshuffling actions are stopped.

For the downlink, the hysteresis time is specified by the DlLdTrnsHysTime parameter; for the uplink, the hysteresis time is 600ms

The UL or DL LDR trigger threshold of a DC-HSDPA cell group equals the sum of the UL or DL LDR trigger thresholds of the two cells in this group. The UL or DL LDR relief threshold of a DC-HSDPA cell group equals the sum of the UL/DL LDR relief thresholds of the two cells in this group. If a DC-HSDPA cell group is in the basic congestion state, the related LDR actions are performed in each cell separately.

The uplink load of an HSUPA cell is calculated based on the uncontrollable load of the cell. The downlink load of an HSDPA cell is calculated based on the load of non-HSPA power and GBP in the cell.

7.1.2 Code Resource

Congestion control based on code resource can be enabled through the CELL_CODE_LDR subparameter of the NBMLdcAlgoSwitch parameter.

If the SF corresponding to the current remaining code of the cell is larger than the value of CellLdrSfResThd, code congestion is triggered and the related load reshuffling actions, as listed in Table 7-2, are taken.

7.1.3 Iub Resource

Congestion control based on Iub resource can be enabled through the IUB_LDR subparameter of the NodeBLdcAlgoSwitch parameter.

Iub congestion control in both the uplink and downlink is NodeB-oriented. In the case of Iub congestion, LDR actions are applied to congestion resolution. Iub congestion is detected in a separate processing module. For details about the decision on Iub congestion detection, see the Transmission Resource Management Feature Parameter Description.

For the basic congestion caused by Iub resource, all UEs under the NodeB are the objects of related LDR actions.

7.1.4 NodeB Credit Resource

The basic congestion caused by NodeB credit resource is of the following types:

Type A: Basic congestion at local cell level

If the cell UL/DL current remaining SF (mapped to credit resource) is higher than UlLdrCreditSfResThd or DlLdrCreditSfResThd (set by running the ADD UCELLLDR command), credit congestion at cell level is triggered and related load reshuffling actions are taken in the current cell.

Type B: Basic congestion at local cell group level (if any)

Type C: Basic congestion at NodeB level

If the cell group or NodeB UL/DL current remaining SF (mapped to credit resource ) is higher than UlLdrCreditSfResThd or DlLdrCreditSfResThd (set by running the ADD UNODEBLDR command), credit congestion at cell group or NodeB level is triggered and related load reshuffling actions are taken. The range of LDR actions is the same as the first type, but the range of UEs to be sorted by priority is different. All the UEs in the normal cells that belong to the cell group or NodeB will be sorted.

Transmission%20Resource%20Management.htm


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The following table lists the LDR switches that need to be set to 1 for different algorithm types.

Table 7-1 LDR switches to be set to 1

Algorithm Load Control Algorithm Switch LDC Algorithm Switch

Type A LC_CREDIT_LDR_SWITCH CELL_CREDIT_LDR

Type B LCG_CREDIT_LDR_SWITCH LCG_CREDIT_LDR

Type C NODEB_CREDIT_LDR_SWITCH NODEB_CREDIT_LDR

7.2 LDR Procedure

When the cell is in the basic congestion state, the RNC takes one of the following actions in each period (specified by the LdrPeriodTimerLen parameter by running the SET ULDCPERIOD command) until the congestion is relieved. These procedures apply to HSPA cells and R99 cells.

For R99 cells, only DCH UEs are selected by LDR actions.

The GoldUserLoadControlSwitch parameter specifies whether the users of gold priority are selected by LDR actions..

Inter-frequency load handover

Code reshuffling

BE service rate reduction

AMR rate reduction

Inter-RAT load handover in the CS domain, which involves the following actions:

− Inter-RAT Should Be Load Handover in the CS Domain

− Inter-RAT Should Not Be Load Handover in the CS Domain

The difference between the "Inter-RAT Should Be Load Handover In the CS/PS Domain" and "Inter-RAT Should Not Be Load Handover In the CS/PS Domain" actions lies in the selection of users. The former only involves CS/PS users with the "service handover" IE in RAB ASSIGNMENT REQUEST set to "handover to GSM should be performed", while the latter only involves CS/PS users with the "service handover" IE set to "handover to GSM should not be performed". For details about the "service handover" IE, see the Handover Feature Parameter Description.

Inter-RAT load handover in the PS domain, which involves the following actions:

− Inter-RAT Should Be Load Handover in the PS Domain

− Inter-RAT Should Not Be Load Handover in the PS Domain

QoS Renegotiation for Uncontrollable Real-Time Services

MBMS power reduction

The LDR actions concerning DC-HSDPA are inter-frequency load handover and inter-RAT handover in PS domain.

The sequence of LDR actions can be changed by running the ADD UCELLLDR command.

The following figure illustrates the detailed LDR procedure. In this example, the sequence of LDR actions is fixed to inter-frequency load handover, code reshuffling, BE rate reduction, inter-RAT handover in CS domain, inter-RAT handover in PS domain, AMR rate reduction, QoS Renegotiation for Uncontrollable Real-Time Services, and MBMS power reduction.

Handover.htm

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7-4

Figure 7-2 LDR procedure

As shown in the preceding figure, when the system is congested, the inter-frequency load handover is initiated first.

If the handover succeeds, the algorithm continues to check whether the system is congested. If the system is still congested, the inter-frequency load handover is initiated again.

If the handover fails, code reshuffling is performed:

− If the code reshuffling succeeds, the algorithm continues to check whether the system is congested. If the system is still congested, the code reshuffling is initiated again.

− If the code reshuffling fails, the next action, that is, BE rate reduction, is taken.

The rest actions to be performed may be deduced by analogy. For details about LDR actions, see section 7.3 "LDR Actions."

The LDR actions that are triggered by basic congestion caused by different resources are different. Table 7-2describes the LDR actions intended for different resources.

When the basic congestion is triggered by different resources, the congestion can be relieved in a order set by running the SET ULDCALGOPARA command.

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Table 7-2 LDR actions intended for different resources

Resource UL/DL Channel LDR Actions

Inte

r-F

req

ue

nc

y L

oa

d

Han

do

ve

r

BE

Ra

te R

ed

uc

tio

n

Inte

r-R

AT

Ha

nd

ov

er

in

CS

Do

ma

in

Inte

r-R

AT

Ha

nd

ov

er

in

PS

Do

ma

in

AM

R R

ate

Re

du

cti

on

Qo

S R

en

eg

oti

ati

on

fo

r

Un

co

ntr

oll

ab

le

Real-

Tim

e S

erv

ices

Co

de

Res

hu

ffli

ng

MB

MS

Po

we

r R

ed

uc

tio

n

Power UL DCH √ √ √ √ √ √

HSUPA √ √ √

DL DCH √ √ √ √ √* √

HSDPA √ √ √

DC-HSDPA √ √

FACH (MBMS)

√*

Iub UL DCH √ √ √

HSUPA √ √

DL DCH √ √ √

HSDPA √ √

FACH (MBMS)

Code - -

DL DCH √ √ √

HSDPA

FACH (MBMS)

Credit UL DCH √ √ √ √

HSUPA √ √ √

DL DCH √ √ √ √

HSDPA

FACH (MBMS)

In the Table 7-2, there are several attentions described in the following.

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The Inter-RAT Handover in CS Domain action can be performed for the HSUPA services that are in the non-scheduling mode.

The Inter-RAT Handover in CS Domain action can be performed for the HSDPA services only when the HsdpaCMPermissionInd parameter is set to TRUE.

If the downlink power-based admission uses the ENU algorithm, the basic congestion can also be caused by the ENU. In this situation, LDR actions do not involve AMR rate reduction or MBMS power reduction, as indicated by the symbol "*" in the preceding table.

In the same environment, different rates have different downlink transmit powers. The higher the rate, the greater the downlink transmit power. Therefore, the load can be reduced by bandwidth reconfiguration.

For HSUPA services, the CE consumption, which is calculated on the basis of the Maximum Bit Rate (MBR), can be reduced through rate downsizing. Therefore, the BE service rate downsizing for HSUPA is applicable only for reduing CE resource congestion.

7.3 LDR Actions

7.3.1 Inter-Frequency Load Handover

Inter-frequency load handover is also called inter frequency load balance (WRFD-020103 Inter-Frequency Load Balance).

If the UE is in the soft handover state, inter-frequency load handover can be performed only when the HO_ALGO_LDR_ALLOW_SHO_SWITCH subparameter of the HoSwitch parameter is set to 1.

The CodeCongSelInterFreqHoInd parameter can be set so that the inter-frequency handover can relieve the basic congestion caused by code resource.

The inter-frequency load handover can be performed based on blind handover or measurement, which can be decided by the InterFreqLDHOMethodSelection parameter.

Inter-Frequency Load Handover Based on Blind Handover

If the InterFreqLDHOMethodSelection parameter is set to BLINDHO, the inter-frequency load handover based on blind handover performs the following steps:

1. The algorithm checks whether cells for inter-frequency blind handover are available. If available, the algorithm goes to the next step. Otherwise, the action fails, and the algorithm takes the next action.

Whether the neighboring cells support blind handover is specified by the parameter BlindHoFlag.

2. The algorithm selects the target cell according to the type of resource that causes the basic congestion:

− If the basic congestion is caused by power resource:

If the candidate cell does not support DC-HSDPA, the algorithm checks whether the load margin of the target cell is higher than both UlInterFreqHoCellLoadSpaceThd and DlInterFreqHoCellLoadSpaceThd and whether the load of the target cell is normal.

If the candidate cell supports DC-HSDPA, the concerned cell group and the candidate cell must have sufficient power margin.

The load margin refers to the difference between the load of the target cell and the basic congestion triggering threshold of the target cell.

If the margin is no higher than the threshold, the action fails, and the algorithm takes the next action.

If there is more than one cell meeting the requirements, the first one is selected as the blind handover target cell.

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− If the basic congestion is caused by code resource:

Whether there are blind handover target cells meeting the requirements is decided by the following conditions:

a. The minimum SF of the target cell is not greater than that of the current cell.

b. The difference of code usage between the current cell and the target cell is greater than LdrCodeUsedSpaceThd.

c. The state of target cell is normal.

If there is no such cell, this action fails and the algorithm takes the next action. If there is more than one cell meeting the requirements, the first cell is selected as the blind handover target cell.

3. The algorithm selects the UEs to be handed over according to the setting of InterFreqLdHoForbidenTC and NbmLdcUeSelSwitch:

− If NbmLdcUeSelSwitch is set to NBM_LDC_MATCH_UE_ONLY, the algorithm performs the following steps:

a. Selects the UEs that meet the following conditions as candidate UEs.

The service types of UEs are not forbidden for LDR handover by parameter InterFreqLdHoForbidenTC.

The service types of UEs are supported by the target cell.

b. Sorts the candidate UEs whose rates are no higher than the handover bandwidth thresholds, based on the integrated priority.

c. Selects the UE with the lowest integrated priority for handover.

− If NbmLdcUeSelSwitch is set to NBM_LDC_MATCH_UE_FIRST, the algorithm performs the following steps:



The service types of UEs are supported by the target cell.

b. Sorts the candidate UEs whose rates are no higher than the handover bandwidth thresholds, based on the integrated priority.


If the rates of all the candidate UEs are higher than the handover bandwidth thresholds, the algorithm performs the following steps:



The service types of UEs are not supported by the target cell.

b. Sorts the UEs whose rates are no higher than the handover bandwidth threshold, based on the integrated priority.


− If NbmLdcUeSelSwitch is set to NBM_LDC_ALL_UE, the algorithm performs the following steps:

a. From the current cell, selects the UEs whose service types are not forbidden for LDR handover by InterFreqLdHoForbidenTC parameter.

b. Sorts the UEs whose rates are no higher than the handover bandwidth thresholds, based on the integrated priority.

b. Selects the UE with the lowest integrated priority for handover.

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If multiple UEs have the same lowest integrated priority, the algorithm selects the one with the highest rate for handover.

The UL and DL handover bandwidth thresholds are specified by UlInterFreqHoBWThd and DlInterFreqHoBWThd respectively. Both the thresholds are considered in the selection of the target UE.

4. After selecting the target cell and the UE, the RNC makes blind handover decision. For details, see the Handover Feature Parameter Description.

Inter-Frequency Load Handover Based on Measurement

Only when the basic congestion is caused by power resource, the inter-frequency load handover based on measurement can be performed.

If the InterFreqLDHOMethodSelection parameter is set to MEASUREHO, the inter-frequency load handover is performed based on measurement. The LDR algorithm is implemented by performing the following steps:

1. The RNC selects the UE whose service types are not forbidden for LDR handover by parameter InterFreqLdHoForbidenTC, and then sorts the selected UEs according to their integrated priority and performs inter-frequency load handover based on measurement on the UE with the lowest integrated priority.

2. The RNC selects the candidate cells that meet the following conditions:

− The cell must be an inter-frequency neighboring cell of the current cell. The cell must not be a DRNC inter-frequency neighboring cell.

− The frequency of the cell is within the band supported by the UE.

− The cell must meet the following conditions on load margin:

If the cell does not support DC-HSDPA, the algorithm checks whether the load margin of the target cell is higher than both UlInterFreqHoCellLoadSpaceThd and DlInterFreqHoCellLoadSpaceThd and whether the load of the target cell is normal.

If the cell supports DC-HSDPA, the concerned cell group and the cell must have sufficient load margin.

− The DrdOrLdrFlag parameter of the cell is set to True, indicating that the cell can be measured.

− If the NbmLdcUeSelSwitch parameter is set to NBM_LDC_MATCH_UE_ONLY, the cell must support the service requested by the UE.

If such candidate target cells do not exist, the inter-frequency load handover action fails and the algorithm takes the next action.

If such candidate cells exist, the following step is performed.

3. The RNC issues a measurement control message to the UE, requesting the UE to measure the signal quality of all candidate cells.

4. The UE measures the RSCP and Ec/No of the candidate cells and periodically reports the measurement results to the RNC. The reporting period is specified by the PrdReportInterval parameter.

5. Based on the received measurement results, the RNC selects the candidate target cells. The candidate target cells must meet the following conditions:

− The cell is not in the basic congestion state.

− The measured RSCP is higher than the RSCP threshold that is specified by the TargetFreqThdRscp parameter.

− The measured Ec/No is higher than the Ec/No threshold that is specified by the TargetFreqThdEcN0 parameter.

If such candidate target cells do not exist, the inter-frequency load handover action fails and the algorithm takes the next action.

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If such candidate target cells exist, the following step is performed.

6. The RNC selects the cell with the highest priority from the candidate target cells to perform inter-frequency hard handover.

− If the handover succeeds, the LDR action is complete.

− If the handover fails, the RNC tries accessing the cell with the second highest priority to perform inter-frequency hard handover until the handover succeeds or it has tried accessing all the candidate target cells.

If the compressed mode is required for the UE to perform inter-frequency measurement, the RNC starts the inter-frequency measurement timer (specified by the InterFreqMeasTime parameter) as soon as the measurement control message is issued. If inter-frequency handover remains unsuccessful until the timer expires, the RNC stops the inter-frequency measurement and cancels the compressed mode.

7.3.2 BE Rate Reduction

When admission control of Power/NodeB Credit is disabled, it is not recommended that the BE Rate Reduction be configured as an LDR action in order to avoid ping-pong effect.

BE rate reduction can only be performed when the DRA_DCCC_SWITCH subparameter of the DraSwitch parameter is set to 1.

The LDR algorithm operates as follows:

1. Based on the integrated priority, the algorithm sorts the BE RABs in descending order.

2. The algorithm selects the BE RABs that meet the following condition:

− The current rate of the BE RAB is higher than the GBR specified by running the SET USERGBR command.

− The BE RAB has the lower integrated priorities.

The number of selected RABs is specified by the UlLdrBERateReductionRabNum or DlLdrBERateReductionRabNum parameter.

If the integrated priorities of some RABs are identical, the RAB with the highest rate is selected.

3. If services can be selected, the action is successful. If services cannot be selected, the action fails. The algorithm takes the next action.

4. The bandwidth of the selected services is reduced to the specified rate. For details about the rate reduction procedure, see the DCCC Feature Parameter Description.

5. The reconfiguration is complete as indicated by the RADIO BEARER RECONFIGURATION message on the Uu interface and through the synchronized radio link reconfiguration procedure on the Iub interface.

7.3.3 QoS Renegotiation for Uncontrollable Real-Time Services

This section describes the WRFD-010506 RAB Quality of Service Renegotiation over Iu Interface feature.

Uncontrollable real-time services refer to PS streaming services. The load can be reduced by adjusting the rates of real-time services through QoS renegotiation.

The uncontrollable real-time service cannot perform rate down automatically like BE service due to the QoS requirement. That is, GBR is specified in RAB assignment procedure and must be guaranteed. When the system needs to adjust service rate to relieve the system load, the RNC has to initiate a rate renegotiation over the Iu interface by requesting a new RAB parameters with a lower bit rate for real time service using RAB Modification procedure.

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The RNC will request a new MBR and GBR that are the lowest ones among the alternative configurations in the RAB ASSIGNMENT message from the CN. However, the CN can decide how to react to the request upon reception of the RAB MODIFY REQUEST message.


1. Based on the integrated priority, the algorithm sorts the RABs for real-time services in the PS domain in descending order.

2. The algorithm selects the RABs with the lowest integrated priorities for QoS renegotiation. The number of selected RABs is specified by the UlLdrPsRTQosRenegRabNum or DlLdrPsRTQosRenegRabNum parameter. If the RNC cannot find an appropriate service for the QoS renegotiation, the action fails. The algorithm takes the next action.

3. The algorithm performs QoS renegotiation for the selected services. The GBR during the service setup is the minimum rate of the service after the QoS renegotiation.

4. The RNC initiates the RAB MODIFY REQUEST message to the CN for the QoS renegotiation. Upon reception of the RAB MODIFY REQUEST message, the CN sends the RAB ASSIGNMENT REQUEST message to the RNC for RAB parameter reconfiguration.

7.3.4 Inter-RAT Handover in the CS Domain

This action can only be performed when the CS inter-RAT handover algorithm is enabled.

The size and coverage mode of a 2G cell are different from those of a 3G cell. Therefore, inter-RAT blind handover is not considered.

Inter-RAT handover in the CS domain involves the following actions.

Inter-RAT Should Be Load Handover in the CS Domain


1. Based on the integrated priority, the algorithm sorts the UEs with the "service handover" IE set to "handover to GSM should be performed" in the CS domain in descending order.

2. The algorithm selects the UEs with the lowest integrated priorities. The number of selected UEs is specified by the UlCSInterRatShouldBeHOUeNum or DlCSInterRatShouldBeHOUeNum parameter.

3. For the selected UEs, the LDR module sends the load handover command to the inter-RAT handover module, requesting the inter-RAT handover module to hand over the UEs to the 2G system.

4. The handover module decides to trigger the inter-RAT handover, depending on the capability of the UE to support the compressed mode.

5. If a UE that meets the handover criteria is not found, the algorithm takes the next action.

Inter-RAT Should Not Be Load Handover in the CS Domain

The algorithm for this action is the same as that for the action "Inter-RAT Should Be Load Handover in the CS Domain". The difference is that this action only involves CS users with the "service handover" IE set to "handover to GSM should not be performed".

The number of selected UEs is specified by the UlCSInterRatShouldNotHOUeNum or DlCSInterRatShouldNotHOUeNum parameter.

7.3.5 Inter-RAT Handover in the PS Domain

This action can only be performed when the PS inter-RAT handover algorithm is enabled.

Inter-RAT handover in the PS domain involves the following actions.

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Inter-RAT Should Be Load Handover in the PS Domain

The algorithm for this action is the same as that for the action "Inter-RAT Should Be Load Handover in the CS Domain". The difference is that this action involves only PS users with the "service handover" IE set to "handover to GSM should be performed".

The number of controlled UEs is determined by the UlPSInterRatShouldBeHOUeNum or DlPSInterRatShouldBeHOUeNum parameter.

Inter-RAT Should Not Be Load Handover in the PS Domain

The algorithm for this action is the same as that for the action "Inter-RAT Should Not Be Load Handover in the CS Domain". The difference is that this action involves only PS users with the "service handover" IE set to "handover to GSM should not be performed".

The number of controlled UEs is specified by the UlPSInterRatShouldNotHOUeNum or DlPSInterRatShouldNotHOUeNum parameter.

HSPA services can be selected only when HsdpaCMPermissionInd is set to TRUE and HsupaCMPermissionInd is not set to Limited.

For details about the two parameters, see the Handover Feature Parameter Description.

7.3.6 AMR Rate Reduction

This action can only be performed when the CS_AMRC_SWITCH subparameter of the parameter CsSwitch parameter is set to 1.

In the WCDMA system, voice services work in eight AMR modes. Each mode has its own rate. Therefore, mode control is functionally equivalent to rate control.

AMR Rate Reduction in the Downlink

In the downlink, the LDR algorithm operates as follows:

1. Based on the integrated priority, the algorithm sorts the RABs in descending order.

2. The algorithm selects the RABs with the lowest integrated priorities and with the rates higher than the GBR for AMR services (conversational). The number of selected RABs is specified by the DlLdrAMRRateReductionRabNum parameter. If the RNC cannot find an appropriate RAB for the AMR rate reduction, the action fails. The algorithm takes the next action.

3. The RNC sends the Rate Control request message through the Iu interface to the CN to adjust the AMR rate to the GBR.

AMR Rate Reduction in the Uplink

In the uplink, the LDR algorithm operates as follows:


2. The algorithm selects the RABs with the lowest integrated priorities and with the rates higher than the GBR for AMR services (conversational). The number of selected RABs is determined by the UlLdrAMRRateReductionRabNum parameter. If the RNC cannot find an appropriate RAB for the AMR rate reduction, the action fails. The algorithm takes the next action.

3. The RNC sends the TFC CONTROL command to the UE to adjust the AMR rate to the GBR.

7.3.7 Code Reshuffling

This section describes the WRFD-020108 Code Resource Management feature .

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To optimize the code usage efficiency, the "left most" principle is adopted in initial code allocation procedure, that is, the code with minimum SF is reserved to ensure that the codes are available for use continuously. However, the code tree may not obey the "left most" principle during actual use. Code reshuffling can be used to make the code tree obey "left most"‟ principle.

When the cell is in the basic congestion state caused by code resource, code reshuffling can be performed to reserve sufficient code resources for subsequent services. Code subtree adjustment refers to the switching of users from one code subtree to another. It is used for decreasing the code fragments to release smaller codes first..

The algorithm operates as follows:

1. Initializes SF_Cur to CellLdrSfResThd.

2. Traverses all the subtrees with this SF_Cur at the root node except the subtrees occupied by common channels and HSDPA channels, and takes the subtrees in which the number of users is not larger than the value of MaxUserNumCodeAdj as candidate subtrees for code reshuffling.

− If such candidate subtrees are available, the algorithm goes to step 3.

− If no such candidate subtree is available, subtree selection fails. This procedure ends.

3. Selects a subtree from the candidate subtrees according to the setting of LdrCodePriUseInd.

− If this parameter is set to TRUE, the algorithm selects the subtree with the largest code number from the candidates.

− If this parameter is set to FALSE, the algorithm selects the subtree with the smallest number of users from the candidates. if multiple subtrees have the same number of users, the algorithm selects the subtree with the largest code number.

4. Treats each user in the subtree as a new user and allocates code resources to each user.

5. Initiates the reconfiguration procedure for each user in the subtree and reconfigures the channelization codes of the users to the newly allocated code resources. The reconfiguration procedure on the UU interface is initiated through the PHYSICAL CHANNEL RECONFIGURATION message and that on the Iub interface through the RL RECONFIGURATION message.

The following figure shows an example of code reshuffling. In this example, CellLdrSfResThd is set to SF8, and MaxUserNumCodeAdj is set to 1.

Figure 7-3 Code reshuffling

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7.3.8 MBMS Power Reduction

The downlink power load can be reduced by lowering power on MBMS traffic channels.

The algorithm operates as follows:


2. The algorithm selects an RAB with the lowest integrated priority and with the current power higher than the minimum transmit power of the corresponding MTCH. That is, it selects an RAB whose ARP value is higher than MbmsDecPowerRabThd.

3. The algorithm triggers a reconfiguration procedure to set the power to the minimum transmit power of the FACH onto which the MTCH is mapped. The reconfiguration procedure on the Iub interface is implemented through the COMMON TRANSPORT CHANNEL RECONFIGURATION REQUEST message.

7.3.9 UL and DL LDR Action Combination of a UE

LDR actions in the uplink and the downlink are independent. Sometimes, the actions in both directions are applied to the same UE. In this situation, the actions are combined as follows:

If the actions in the two directions are identical, the actions are combined. For example, if BE rate reduction actions in both the uplink and the downlink need to be applied to the same UE, then only a single RADIO BEARER RECONFIGURATION message is sent out.

If the actions in the two directions are different and if one direction requires inter-frequency handover, the UE undergoes the inter-frequency handover. The action in the other direction is not taken.

If the actions in the two directions are different and if one direction requires the inter-RAT handover, the UE undergoes the inter-RAT handover. The other action is not taken.

If the action in one direction requires inter-frequency handover, and the action in the other direction requires inter-RAT handover, the UE undergoes the UL LDR action. The DL LDR action is not taken.

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Load Control 8 Overload Control



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8 Overload Control

This chapter describes the WRFD-020107 Overload Control feature.

After the UE access is allowed, the power consumed by a single link is adjusted by the single link power control function. The power varies with all kinds of factors such as the mobility of the UE and the changes in the environment. In some situations, the total power load of the cell can be higher than the target load. To ensure the system stability, Overload Control (OLC) must be performed.

8.1 Overload Triggering

Only the power resource and Iub bandwidth may result in the overload congestion state. Hard resources such as the ENU and credit resources do not cause overload congestion.

For details about overload congestion caused by Iub bandwidth and details about user release, see the Transmission Resource Management Feature Parameter Description.

OLC can be enabled through the UL_UU_OLC and DL_UU_OLC subparameters of the NBMLdcAlgoSwitch parameter.

The following figure shows the triggering and release of cell power overload.

Figure 8-1 Triggering and release of cell power overload

As shown in Figure 8-1, if the UL/DL load of the cell is higher than or equal to the UlOlcTrigThd or DlOlcTrigThd for a hysteresis time, the cell is in the overload state, and the related overload handling action is taken. If the current UL/DL load of the cell is lower than the UlOlcRelThd or DlOlcRelThd for a hysteresis time, the overload state of the cell is released and the related overload handling is stopped.

For the downlink, the hysteresis time is specified by the DlLdTrnsHysTime parameter; for the uplink, the hysteresis time is 600ms.



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The UL or DL OLC trigger threshold of a DC-HSDPA cell group equals the sum of the UL or DL OLC trigger thresholds of the two cells in this group. The UL or DL OLC relief threshold of a DC-HSDPA cell group equals the sum of the UL or DL OLC relief thresholds of the two cells in this group. If a DC-HSDPA cell group is overloaded, the related overload handling is performed in each cell separately.

The uplink load of an HSUPA cell is calculated based on the uncontrollable load of the cell. The downlink load of an HSDPA cell is calculated based on the load of non-HSPA power and GBP in the cell.

In addition to periodic measurement, event-triggered measurement is applicable to OLC.

If OLC_EVENTMEAS is set to 1, the RNC sends the NodeB a request for event measurement based on power resource. In the associated request message, the reporting criterion is specified, including UlOlcTrigHyst / DlOlcTrigHyst, UlOlcTrigThd / DlOlcTrigThd, and UlOlcRelThd / DlOlcRelThd. Then the NodeB checks the current power load in real time according to this criterion and reports the status to the RNC periodically if the conditions of reporting are met.

Limited by 3GPP, the NodeB cannot check the total load of the non-HSDPA power and the GBP. Therefore, the recommended setting of OLC_EVENTMEAS is 0 for HSDPA cells.

8.2 General OLC Procedure

When the cell is overloaded, the RNC takes one of the following actions in each period specified by the OlcPeriodTimerLen parameter until the congestion is relieved:

Performing TF Control of BE Services

Switching BE Services to Common Channels

Adjusting the Maximum FACH TX Power

Releasing Some RABs

The following figure shows the OLC procedure.

Figure 8-2 OLC procedure

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As shown in the preceding figure, the OLC procedure is as follows:

1. The OLC takes the first action to perform TF control.

− If the TF control succeeds, the OLC checks whether the system is overloaded. If yes, the OLC performs TF control again.

− If the TF control fails, go to 2.

2. The OLC takes the second action to switch BE services to common channels.

− If the switching succeeds, the OLC checks whether the system is overloaded. If yes, the OLC switches BE services to common channels again.

− If the switching fails, go to 3.

3. The OLC takes the third action to adjust the maximum FACH transmit power.

− If the adjustment succeeds, the OLC checks whether the system is overloaded. If yes, the OLC adjusts the power again.

− If the adjustment fails, the OLC takes the fourth action to release some RABs.

For details about OLC actions, see section 8.3 "OLC Actions."

When the cell is in the overload congestion state:

The state transition from FACH to DCH is prohibited.

Whether the admission for users over FACH channels is permitted can be set through FACH_UU_ADCTRL subparameter of NBMCacAlgoSwitch parameter. Except this, only resources requests of RRC connection setup whose cause is emergency call, detach, or registration are permitted, because the priority of such requests is very high.

8.3 OLC Actions

8.3.1 Performing TF Control of BE Services

OLC Algorithm for TF Control in the Downlink

For the TF control in the downlink, the OLC algorithm operates as follows:


2. The algorithm selects the following RABs:

− DCH RABs with the rates higher than DlDcccRateThd. For details about the parameter, see the DCCC Feature Parameter Description.

− RABs with the lowest integrated priorities.

The number of RABs selected is smaller than or equal to DlOlcFTFRstrctRabNum.

If the RNC cannot find an appropriate service for the TF control, the OLC takes the next action.

3. The RNC sends the TF control indication message to the MAC. Each MAC of the selected RABs will receive one TF control indication message and will restrict the transport format combination (TFC) selection of the BE services to reduce the data rate step by step.

The MAC restricts the TFC selection according to the following formula:

TFmax(N+1) = TFmax(N) x Ratelimitcoeff

Here:

− TFmax(0) is the maximum TB number of the BE service before the service is selected for TF control.

− TFmax(N+1) is the maximum TB number during the period from (T0 + RateRstrctTimerLen x N) to (T0 + RateRstrctTimerLen x (N + 1)), where T0 is the time when the MAC receives the TF control indication message.

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− Ratelimitcoeff is specified by the RateRstrctCoef parameter.

4. If the number of times that TF control is performed exceeds DlOlcFTFRstrctTimes, the action fails. The OLC takes the next action.

5. If the congestion is relieved, the RNC sends the congestion relief indication to the MAC. At the same time, the rate recovery timer (RateRecoverTimerLen) is started. When this timer expires, the MAC increases the data rate step by step.

MAC recovers the TFC selection by calculating the maximum TB number according to the following formula:

TFmax(N+1) = TFmax(N) x RateRecoverCoeff

Here:

− TFmax(0) is the maximum TB number of the BE service before congestion relief indication is received.

− TFmax(N+1) is the maximum TB number during the period from (T1 + RateRecoverTimerLen x N) to (T1 + (RateRecoverTimerLen x (N + 1)), where T1 is the time when the MAC receives the congestion relief indication message.

− RateRecoverCoeff is specified by the RecoverCoef parameter.

OLC Algorithm for TF Control in the Uplink

For a UE with the DCH service, the RNC sends a TRANSPORT FORMAT COMBINATION CONTROL message to the UE to restrict the TFC of the UE, according to the 3GPP TS25.331. The UE does not reply to the RNC befor the procedure is performed successfully.

For the TF control in the uplink, the OLC algorithm operates as follows:

1. Based on the integrated priority, the algorithm sorts the DCH RABs in descending order.

2. The algorithm selects the following RABs:

− RABs with the rates higher than UlDcccRateThd. For details about the parameter, see the DCCC Feature Parameter Description.

− RABs with the lowest integrated priorities.

The number of selected RABs is specified by the UlOlcFTFRstrctRabNum parameter.

If the RNC cannot find an appropriate service, the OLC performs the next action.

3. The RNC sends the TRANSPORT FORMAT COMBINATION CONTROL message to the UE that accesses the specified service. This message contains the following IEs:

− Transport Format Combination Set Identity: defines the available TFC that the UE can select, that is, the restricted TFC sub-set. It is always the two TFCs corresponding to the lowest data rate.

− TFC Control Duration: defines the period the restricted TFC sub-set is to be applied. It is set to a random value (integer multiples of 10 ms) from the range of 10 ms to 5120 ms to avoid data rate upsizing at the same time.

After the TFC control duration expires, the UE can apply any TFC of TFCS before the TF control.

4. If the number of times that TF control is performed exceeds UlOlcFTFRstrctTimes, the action fails. The OLC takes the next action.

8.3.2 Switching BE Services to Common Channels

Whether the selected UEs can be switched to common channels depends on the setting of DRA_PS_BE_STATE_TRANS_SWITCH, DRA_HSDPA_STATE_TRANS_SWITCH, or DRA_HSUPA_STATE_TRANS_SWITCH in the parameter DraSwitch.

For the switching of uplink BE services to common channels, if the control RTWP anti-interference function switch (NBMCacAlgoSwitch: RTWP_RESIST_DISTURB) is turned on, the RNC checks

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whether the uplink equivalent user load proportion of the cell is lower than 40%. If it is lower than 40%, the RNC does not perform this operation.

For switching BE services to common channels, the OLC algorithm operates as follows:

1. Based on the integrated priority, the algorithm sorts all the UEs in the PS domain in descending order.

2. The algorithm selects the UEs with the lowest integrated priorities. The number of selected UEs is specified by TransCchUserNum. If the selection fails, the OLC takes the next action.

This function is disabled when the TransCchUserNum parameter is set to 0.

3. The OLC switches the selected UEs to common channels.

8.3.3 Adjusting the Maximum FACH TX Power

The procedure for adjusting the maximum FACH transmit power is as follows:

1. Set the maximum FACH transmit power to the target maximum transmit power. The target maximum transmit power is calculated according to the following formula:

Ptarget = Pmax - Delta

− Ptarget is the target maximum transmit power.

− Pmax is the maximum FACH transmit power (MaxFachPower).

− Delta is the FACH power reduction step (FACHPwrReduceValue).

2. If the congestion is relieved after the power adjustment, the system starts the FACH power recovery timer, which is set to 5s. When the timer expires, the maximum FACH transmit power is increased to the original maximum FACH transmit power if the system is always in the normal state before the timer expires.

The preceding power adjustment is applicable to only the FACH carrying common services rather than MBMS services.

8.3.4 Releasing Some RABs

OLC Algorithm for the Release of Some RABs in the Uplink

If the Control RTWP Anti-interference algorithm switch (NBMCacAlgoSwitch: RTWP_RESIST_DISTURB) is enabled, the RNC checks whether the uplink equivalent user load proportion of the cell is lower than 40% before performing this operation. If it is lower than 40%, the RNC does not perform this operation.

For the release of some RABs in the uplink, the OLC algorithm operates as follows:

1. Based on the integrated priority, the algorithm sorts all RABs including HSUPA and DCH services in descending order.

2. The algorithm selects the RABs with the lowest integrated priorities. If the integrated priorities of some RABs are identical, it selects the RAB with a higher rate (that is, the current rate for DCH RAB or the GBR for HSUPA RAB) in the uplink. The number of selected RABs is specified by UlOlcTraffRelRabNum.

3. The selected RABs are released directly.

OLC Algorithm for the Release of Some RABs in the Downlink

For the release of some RABs in the downlink, the OLC algorithm operates as follows:

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If the SeqOfUserRel parameter is set to USER_REL, then:

1. Based on the integrated priority, the algorithm sorts all non-MBMS RABs in descending order.

2. The algorithm selects the RABs with the lowest integrated priorities. If the integrated priorities of some RABs are identical, it selects the RAB with a higher rate (that is, the current rate for DCH RAB or the GBR for HSDPA RAB) in the downlink. The number of selected RABs is specified by DlOlcTraffRelRabNum.

3. The selected RABs are directly released.

4. If all non-MBMS RABs are released but congestion persists in the downlink, MBMS RABs are selected.

If the SeqOfUserRel parameter is set to MBMS_REL, then:

1. Based on the ARP, the algorithm sorts all MBMS RABs in descending order.

2. The algorithm selects the RABs with the lowest integrated priorities. The number of selected RABs is specified by MbmsOlcRelNum.

3. The selected RABs are directly released.

4. If all MBMS RABs are released but congestion persists in the downlink, non-MBMS RABs are selected.

This function is disabled when all the UlOlcTraffRelRabNum, DlOlcTraffRelRabNum, and MbmsOlcRelNum parameters are set to 0.

The higher the value of UlOlcTraffRelRabNum or DlOlcTraffRelRabNum is, the more the cell load decreases, which will affect the users experience negatively.

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Load Control 9 Parameters



9-1

9 Parameters

Table 9-1 Parameter description

Parameter ID NE MML Command Description

BackgroundNoise

BSC6900

ADD UCELLCAC(Optional) MOD UCELLCAC(Optional)

Meaning: If [Auto-Adaptive Background Noise Update Switch] is set to OFF, it is used to set background noise of the cell. If [Auto-Adaptive Background Noise Update Switch] is set to ON, new background noise is restricted by this parameter and "BgnAbnormalThd". For detailed information of this parameter, refer to the 3GPP TS 25.133. GUI Value Range: 0~621 Actual Value Range: -112~-50, step:0.1 Unit: dBm Default Value: 61

BgnAbnormalThd

BSC6900


Meaning: This parameter is applied when "BGNSwitch" is set to ON. (1) If the difference of measured background noise without filtered and the current background noise is larger than the RTWP threshold, the background noise will not be updated. (2) If the difference of new background noise and the configured value is larger than the RTWP threshold, the background noise will not be updated. GUI Value Range: 1~400 Actual Value Range: 0.1~40, step:0.1 Unit: dB Default Value: 100

BGNAdjustTimeLen

BSC6900


Meaning: Only when the measured background noise's duration reaches this parameter, the output of the auto-adaptive background noise update filter could be regarded as effect background noise, and the current value is replaced with the new one. At the same time, the auto-adaptive status should be restarted; otherwise, the output could not be regarded as the effective background noise. GUI Value Range: 1~6000 Actual Value Range: 1~6000 Unit: s Default Value: 120

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BgnEndTime BSC6900

ADD UCELLCAC(Mandatory) MOD UCELLCAC(Mandatory)

Meaning: (1) This parameter, along with the [Algorithm start time], is used to limit the validation time of the background noise automatic update algorithm. If [Algorithm stop time] is greater than [Algorithm start time], and the background noise automatic update algorithm is enabled, then the algorithm is activated during the period of [Algorithm stop time] to [Algorithm start time] each day. In other periods, the algorithm fails. If [Algorithm stop time] is less than [Algorithm start time], and the background noise automatic update algorithm is enabled, then the algorithm is activated during the period of [Algorithm stop time] each day to [Algorithm start time] of the next day. In other periods, the algorithm fails (2) Input format: HH&MM&SS GUI Value Range: hour, min, sec Actual Value Range: hour{0~23}, min{0~59}, sec{0~59} Unit: None Default Value: None

BGNEqUserNumThd

BSC6900


Meaning: When the number of uplink equivalent users is not larger than this parameter, the RTWP could be regarded as background noise. Therefore, the measured RTWP could be input to the auto-adaptive background noise update filter; otherwise, the RTWP could not be regarded as background noise, and should not be input to the filter, and at the same time, the auto-adaptive status should be reset. GUI Value Range: 0~10 Actual Value Range: 0~10 Unit: None Default Value: 0

BgnStartTime

BSC6900

ADD UCELLCAC(Mandatory) MOD UCELLCAC(Mandatory)

Meaning: (1) This parameter, along with the [Algorithm stop time], is used to limit the validation time of the background noise automatic update algorithm. If [Algorithm stop time] is greater than [Algorithm start time], and the background noise automatic update algorithm is enabled, then the algorithm is activated during the period of [Algorithm stop time] to [Algorithm start time] each day. In other periods, the algorithm fails. If [Algorithm stop time] is less than [Algorithm start time], and the background noise automatic update algorithm is enabled, then the algorithm is activated during the period of [Algorithm stop time] each day to [Algorithm start time] of the next day. In other periods, the algorithm fails. (2) Input format: HH&MM&SS GUI Value Range: hour, min, sec Actual Value Range: hour{0~23}, min{0~59}, sec{0~59} Unit: None Default Value: None

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BGNSwitch BSC6900


Meaning: When the parameter is 'OFF', the auto-adaptive background noise update algorithm is switched off. Otherwise, the algorithm is switched on. GUI Value Range: OFF, ON Actual Value Range: OFF, ON Unit: None Default Value: ON

BgnUpdateThd

BSC6900


Meaning: The difference of RTWP that trigger the update of background noise. If the difference is larger than the threshold, the background will be updated. GUI Value Range: 1~100 Actual Value Range: 0.1~10, step:0.1 Unit: dBm Default Value: 5

CarrierTypePriorInd

BSC6900

ADD UOPERUSERPRIORITY(Optional) MOD UOPERUSERPRIORITY(Optional)

Meaning: Decide which carrier is prior when ARP and TrafficClass are both identical. GUI Value Range: NONE, DCH, HSPA Actual Value Range: NONE, DCH, HSPA Unit: None Default Value: NONE

CellLdrSfResThd

BSC6900

ADD UCELLLDR(Optional) MOD UCELLLDR(Optional)

Meaning: This parameter specifies the Cell SF reserved threshold used for judging whether the code load reshuffling (LDR) is allowed. The code load reshuffling could be triggered only when the minimum available SF of a cell is higher than this threshold GUI Value Range: SF4(SF4), SF8(SF8), SF16(SF16), SF32(SF32), SF64(SF64), SF128(SF128), SF256(SF256) Actual Value Range: SF4, SF8, SF16, SF32, SF64, SF128, SF256 Unit: None Default Value: SF8

CellOverrunThd

BSC6900

ADD UCELLLDB(Optional) MOD UCELLLDB(Optional)

Meaning: If the cell downlink load exceeds this threshold, the algorithm will decrease the pilot transmit power of the cell so as to increase the whole system's capacity. This parameter is based on network planning. GUI Value Range: 0~100 Actual Value Range: 0~1, step:0.01 Unit: % Default Value: 90

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CellUnderrunThd

BSC6900


Meaning: If the cell downlink load is lower than this threshold, the algorithm will increase the pilot transmit power of the cell so as to share load of other cells. This parameter is based on network planning. GUI Value Range: 0~100 Actual Value Range: 0~1, step:0.01 Unit: % Default Value: 30

ChoiceRprtUnitForDlBasicMeas

BSC6900

SET ULDM(Optional)

Meaning: If you set this parameter to TEN_MSEC, use [DL basic meas rprt cycle,Unit:10ms] to specify the measurement report period. If you set this parameter to MIN, use [DL basic meas rprt cycle,Unit:min] to specify measurement report period. For detailed information of this parameter, refer to 3GPP TS 25.433. GUI Value Range: TEN_MSEC, MIN Actual Value Range: TEN_MSEC, MIN Unit: None Default Value: TEN_MSEC

ChoiceRprtUnitForHsdpaPwrMeas

BSC6900

SET ULDM(Optional)

Meaning: If you set this parameter to TEN_MSEC, use [HSDPA need pwr meas cycle,Unit:10ms] to specify the measurement report period. If you set this parameter to MIN, use [HSDPA need pwr meas cycle,Unit:min] to specify measurement report period. For detailed information of this parameter, refer to 3GPP TS 25.433. GUI Value Range: TEN_MSEC, MIN Actual Value Range: TEN_MSEC, MIN Unit: None Default Value: TEN_MSEC

ChoiceRprtUnitForHsdpaRateMeas

BSC6900

SET ULDM(Optional)

Meaning: If you set this parameter to TEN_MSEC, use [HSDPA bit rate meas cycle,Unit:10ms] to specify the measurement report period. If you set this parameter to MIN, use [HSDPA bit rate meas cycle,Unit:min] to specify measurement report period. For detailed information of this parameter, refer to 3GPP TS 25.433. GUI Value Range: TEN_MSEC, MIN Actual Value Range: TEN_MSEC, MIN Unit: None Default Value: TEN_MSEC

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ChoiceRprtUnitForHsupaRateMeas

BSC6900

SET ULDM(Optional)

Meaning: If you set this parameter to TEN_MSEC, use [HSDPA bit rate meas cycle,Unit:10ms] to specify the measurement report period. If you set this parameter to MIN, use [HSDPA bit rate meas cycle,Unit:min] to specify measurement report period. For detailed information of this parameter, refer to 3GPP TS 25.433. GUI Value Range: TEN_MSEC, MIN Actual Value Range: TEN_MSEC, MIN Unit: None Default Value: TEN_MSEC

ChoiceRprtUnitForUlBasicMeas

BSC6900

SET ULDM(Optional)

Meaning: If you set this parameter to TEN_MSEC, use [UL basic meas rprt cycle,Unit:10ms] to specify the measurement report period. If you set this parameter to MIN, use [UL basic meas rprt cycle,Unit:min] to specify measurement report period. For detailed information of this parameter, refer to 3GPP TS 25.433. GUI Value Range: TEN_MSEC, MIN Actual Value Range: TEN_MSEC, MIN Unit: None Default Value: TEN_MSEC

CodeCongSelInterFreqHoInd

BSC6900


Meaning: This switch is valid only when the inter-frequency handover switch is enabled. TRUE means that inter-frequency handover is selected in code resource congestion. FALSE means that inter-frequency handover is not selected in code resource congestion. This parameter should be set based on network resource usage. In the case of multi-frequency coverage, if code resources present a bottleneck, such as indoor environment, the parameter is recommended to be set to TRUE. GUI Value Range: FALSE(FALSE), TRUE(TRUE) Actual Value Range: FALSE, TRUE Unit: None Default Value: False

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ConnectFailRrcRedirSwitch

BSC6900

SET UDRD(Optional)

Meaning: RRC redirection switch used in the case of admission failure. It is valid only when the "DR_RRC_DRD_SWITCH" parameter is set to ON. - OFF indicates that the RRC redirection is not allowed. - Only_To_Inter_Frequency indicates that only RRC redirection to inter-frequency cells is allowed. - Allowed_To_Inter_RAT indicates that both RRC redirection to inter-frequency cells and redirection to inter-RAT cells are allowed. GUI Value Range: OFF, Only_To_Inter_Frequency, Allowed_To_Inter_RAT Actual Value Range: OFF, Only_To_Inter_Frequency, Allowed_To_Inter_RAT Unit: None Default Value: Only_To_Inter_Frequency

CsSwitch BSC6900

SET UCORRMALGOSWITCH(Optional)

Meaning: CS algorithm switch group. 1) CS_AMRC_SWITCH: When the switch is on and the AMRC license is activated, the AMR control function is enabled for AMR services. 2) CS_HANDOVER_TO_UTRAN_DEFAULT_CFG_SWITCH: When the switch is on, the default configurations of signaling and RABs, which are stipulated in 3GPP 25.331, are used for relocation of the UE from GSM to WCDMA. When the switch is not on, the default configurations are not used. Instead, the complete information of RB, TrCH, and PhyCH, which are in the HANDOVER TO UTRAN COMMAND message is used. 3) CS_IUUP_V2_SUPPORT_SWITCH: When the switch is on and the "Support IUUP Version 2" license is activated, the RNC supports the TFO/TRFO function. GUI Value Range: CS_AMRC_SWITCH, CS_HANDOVER_TO_UTRAN_DEFAULT_CFG_SWITCH, CS_IUUP_V2_SUPPORT_SWITCH Actual Value Range: CS_AMRC_SWITCH, CS_HANDOVER_TO_UTRAN_DEFAULT_CFG_SWITCH, CS_IUUP_V2_SUPPORT_SWITCH Unit: None Default Value: None

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DlBasicCommMeasFilterCoeff

BSC6900

SET ULDM(Optional)

Meaning: L3 filtering coefficient. The larger the value of this parameter, the stronger the smoothing effect and the higher the anti-slow-fading capability, but the lower the signal change tracing capability. For detailed information of this parameter, refer to 3GPP TS 25.433. GUI Value Range: D0, D1, D2, D3, D4, D5, D6, D7, D8, D9, D11, D13, D15, D17, D19 Actual Value Range: D0, D1, D2, D3, D4, D5, D6, D7, D8, D9, D11, D13, D15, D17, D19 Unit: None Default Value: D6

DlBeTraffInitBitrate

BSC6900

SET UFRC(Optional)

Meaning: DL initial access rate of PS background or interactive service. When DCCC function is enabled, the downlink initial access rate will be set to this value if the downlink maximum rate is higher than the initial access rate. GUI Value Range: D8, D16, D32, D64, D128, D144, D256, D384 Actual Value Range: 8, 16, 32, 64, 128, 144, 256, 384 Unit: kbit/s Default Value: D64

DlCacAvgFilterLen

BSC6900

SET ULDM(Optional)

Meaning: Length of smoothing filter window of downlink CAC. GUI Value Range: 1~32 Actual Value Range: 1~32 Unit: None Default Value: 5

DlCSInterRatShouldBeHOUeNum

BSC6900


Meaning: Number of users selected in a DL LDR CS domain inter-RAT SHOULDBE load handover. The target subscribers of this parameter are the CS domain subscribers. Because the CS domain subscribers are session subscribers in general and they have little impact on load, you can set this parameter to a comparatively high value. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None Default Value: 3

DlCSInterRatShouldNotHOUeNum

BSC6900


Meaning: Number of users selected in a DL LDR CS domain inter-RAT SHOULDNOTBE load handover. The target subscribers of this parameter are the CS domain subscribers. Because the CS domain subscribers are session subscribers in general and they have little impact on load, you can set this parameter to a comparatively high value. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None

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Default Value: 3

DlDcccRateThd

BSC6900

SET UDCCC(Optional)

Meaning: For a BE service that has a low maximum rate, the DCCC algorithm is not obviously effective yet it increases algorithm processing. Thus, the traffic-based DCCC algorithm is applied to BE services whose maximum DL rate is greater than the threshold. GUI Value Range: D8, D16, D32, D64, D128, D144, D256, D384 Actual Value Range: 8, 16, 32, 64, 128, 144, 256, 384 Unit: kbit/s Default Value: D64

DlInterFreqHoBWThd

BSC6900


Meaning: The UE can be selected to process load handover only when its bandwidth is less than this threshold. GUI Value Range: 0~400000 Actual Value Range: 0~400000 Unit: bit/s Default Value: 200000

DlInterFreqHoCellLoadSpaceThd

BSC6900


Meaning: The inter-frequency neighboring cell could be selected as the destination of load handover only when its load remaining space is larger than this threshold. The lower the parameter is, the easier it is to find a qualified target cell for the blind handover. Excessively small value of the parameter, however makes the target cell easily enter the congestion status. The higher the parameter is, the more difficult it is for the inter-frequency blind handover occurs. GUI Value Range: 0~100 Actual Value Range: 0~1, step:0.01 Unit: % Default Value: 20

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DlLdrAMRRateReductionRabNum

BSC6900


Meaning: The mechanism of the LDR is that an action is performed in each [LDR period] and some services are selected based on the action rules to perform this action. This parameter defines the maximum number of RABs selected in executing downlink LDR-AMR voice service rate reduction. If the parameter value is too high, the LDR action may fluctuate greatly and over control may occur (the state of basic congestion turns into another extreme--under load). If the parameter value is too low, the LDR action has a slow response and the effect is not apparent, affecting the LDR performance. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None Default Value: 1

DlLdrAvgFilterLen

BSC6900

SET ULDM(Optional)

Meaning: Length of smoothing filter window of downlink LDR. GUI Value Range: 1~32 Actual Value Range: 1~32 Unit: None Default Value: 5

DlLdrBERateReductionRabNum

BSC6900


Meaning: Number of RABs selected in a DL LDR BE traffic rate reduction. In the actual system, this parameter can be set on the basis of the actual circumstances. If the high-rate subscribers occupy a high proportion, set the parameter to a comparatively low value. If the high-rate subscribers occupy a low proportion, set the parameter to a comparatively high value. Because the basic congestion control algorithm is designed to slowly decrease cell load, you need to set this parameter to a comparatively low value. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None Default Value: 1

DlLdrCreditSfResThd

BSC6900


Meaning: Reserved SF threshold in downlink credit LDR. The downlink credit LDR could be triggered only when the SF factor corresponding to the downlink reserved credit is higher than the uplink or downlink credit SF reserved threshold. GUI Value Range: SF4(SF4), SF8(SF8), SF16(SF16), SF32(SF32), SF64(SF64), SF128(SF128), SF256(SF256) Actual Value Range: SF4, SF8, SF16, SF32, SF64, SF128, SF256 Unit: None Default Value: SF8

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DlLdrPsRTQosRenegRabNum

BSC6900


Meaning: Number of RABs selected in a DL LDR uncontrolled real-time traffic QoS renegotiation. The target subscribers of this parameter are the PS domain real-time subscribers. The setting of this parameter is analogous to the setting of BE service rate reduction subscriber number. Because the number of subscribers performing QoS renegotiation may be smaller than the value of this parameter, for example, the candidate subscribers selected for downlink LDR do not meet the QoS renegotiation conditions, you must leave some margin when setting this parameter to ensure the success of load reshuffling. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None Default Value: 1

DlLdrRelThd BSC6900

ADD UCELLLDM(Optional) MOD UCELLLDM(Optional)

Meaning: If the ratio of DL load of the cell to the downlink capacity is lower than this threshold, the DL load reshuffling function of the cell is stopped. After the basic congestion state of the cell load is released, the system no longer implements the LDR action. Because the load fluctuates, the difference between the LDR release threshold and trigger threshold should be higher than 10%. The ping-pong effect of the preliminary congestion state may occur. GUI Value Range: 0~100 Actual Value Range: 0~1, step:0.01 Unit: % Default Value: 60

DlOlcAvgFilterLen

BSC6900

SET ULDM(Optional)

Meaning: Length of smoothing filter window of downlink OLC. GUI Value Range: 1~32 Actual Value Range: 1~32 Unit: None Default Value: 5

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DlOlcFTFRstrctRabNum

BSC6900

ADD UCELLOLC(Optional) MOD UCELLOLC(Optional)

Meaning: DL fast TF restriction refers to a situation where, when the cell is overloaded and congested, the downlink TF can be adjusted to restrict the number of blocks transported in each TTI at the MAC layer and the rate of user data, thus reducing the cell downlink load. The mechanism of the OLC is that an action is performed in each [OLC period] and some services are selected based on the action rules to perform this action. This parameter defines the maximum number of RABs selected in executing downlink OLC fast restriction. Selection of RABs of the OLC is based on the service priorities and ARP values and bearing priority indication. The RAB of low priority is under control. In the actual system, UlOlcFTFRstrctRabNum and DlOlcFTFRstrctRabNum can be set on the basis of the actual circumstances. If the high-rate subscribers occupy a high proportion, set UlOlcFTFRstrctRabNum and DlOlcFTFRstrctRabNum to comparatively low values. If the high-rate subscribers occupy a low proportion, set UlOlcFTFRstrctRabNum and DlOlcFTFRstrctRabNum to comparatively high values. The higher the parameters are, the more users are involved in fast TF restriction under the same conditions, the quicker the cell load decreases, and the more user QoS is affected. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None Default Value: 3

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DlOlcFTFRstrctTimes

BSC6900


Meaning: DL fast TF restriction refers to a situation where, when the cell is overloaded and congested, the downlink TF can be adjusted to restrict the number of blocks transported in each TTI at the MAC layer and the rate of user data, thus reducing the cell downlink load. The mechanism of the OLC is that an action is performed in each [OLC period] and some services are selected based on the action rules to perform this action. This parameter defines the maximum number of downlink OLC fast TF restriction performed in entering/exiting the OLC status. After the overload is triggered, the RNC immediately executes OLC by first executing fast TF restriction. The internal counter is incremented by 1 with each execution. If the number of overloads does not exceed the OLC action threshold, the system lowers the BE service rate by lowering TF to relieve the overload. If the number of overloads exceeds the OLC action threshold, the previous operation has no obvious effect on alleviating the overload and the system has to release users to solve the overload problem. The lower the parameters are, the more likely the users are released, resulting in negative effect on the system performance. If the parameters are excessively high, the overload status is released slowly. GUI Value Range: 0~100 Actual Value Range: 0~100 Unit: None Default Value: 3

DlOlcMeasFilterCoeff

BSC6900

SET ULDM(Optional)


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DlOlcRelThd BSC6900


Meaning: If the ratio of DL load of the cell to the downlink capacity is lower than this threshold, the DL overload and congestion control function of the cell is stopped. The value of the OLC release threshold should not be much lower than or close to the OLC trigger threshold, or the system state may have a ping-pong effect. The recommended difference between the OLC release threshold and the OLC trigger threshold is higher than 10%. It is desirable to set the two parameters a bit higher given that the difference between OLC trigger threshold and OLC release threshold is fixed. GUI Value Range: 0~100 Actual Value Range: 0~1, step:0.01 Unit: % Default Value: 85

DlOlcTraffRelRabNum

BSC6900


Meaning: User release is an extreme method in reducing the cell load and recovering the system when the cell is overloaded and congested. The mechanism of the OLC is that an action is performed in each [OLC period] and some services are selected based on the action rules to perform this action. This parameter defines the maximum number of RABs released in executing downlink OLC service release. For the users of a single service, the releasing of RABs means the complete releasing of the users. The releasing of RABs causes call drops, so UlOlcFTFRstrctTimes or DlOlcFTFRstrctTimes should be set to a low value. Higher values of the parameter get the cell load to decrease more obviously, but the QoS will be affected. GUI Value Range: 0~10 Actual Value Range: 0~10 Unit: None Default Value: 0

DlOlcTrigHyst

BSC6900

SET ULDM(Optional)

Meaning: DL OLC trigger hysteresis.This parameter can avoid touching off OLC event continually. GUI Value Range: 1~6000 Actual Value Range: 10~60000, step:10 Unit: None Default Value: 100

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DlOlcTrigThd BSC6900


Meaning: If the ratio of DL load of the cell to the downlink capacity is not lower than this threshold, the DL overload and congestion control function of the cell is triggered. The value of the OLC release threshold should not be much lower than or close to the OLC trigger threshold, or the system state may have a ping-pong effect. The recommended difference between the OLC release threshold and the OLC trigger threshold is higher than 10%. It is desirable to set the two parameters a bit higher given that the difference between OLC trigger threshold and OLC release threshold is fixed. GUI Value Range: 0~100 Actual Value Range: 0~1, step:0.01 Unit: % Default Value: 95

DlPSInterRatShouldBeHOUeNum

BSC6900


Meaning: Number of users selected in a DL LDR PS domain inter-RAT SHOULDBE load handover. The target subscribers of this parameter are the PS domain subscribers. In the actual system, this parameter can be set on the basis of the actual circumstances. If the high-rate subscribers occupy a high proportion, set the parameter to a comparatively low value. If the high-rate subscribers occupy a low proportion, set the parameter to a comparatively high value. Because the basic congestion control algorithm is designed to slowly decrease cell load, you need to set this parameter to a comparatively low value. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None Default Value: 1

DlPSInterRatShouldNotHOUeNum

BSC6900


Meaning: Number of users selected in a DL LDR PS domain inter-RAT SHOULDNOTBE load handover. The target subscribers of this parameter are the PS domain subscribers. In the actual system, this parameter can be set on the basis of the actual circumstances. If the high-rate subscribers occupy a high proportion, set the parameter to a comparatively low value. If the high-rate subscribers occupy a low proportion, set the parameter to a comparatively high value. Because the basic congestion control algorithm is designed to slowly decrease cell load, you need to set this parameter to a comparatively low value. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None Default Value: 1

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DraSwitch BSC6900


Meaning: Dynamic resource allocation switch group. 1) DRA_AQM_SWITCH: When the switch is on, the active queue management algorithm is used for the RNC. 2) DRA_BASE_ADM_CE_BE_TTI_L2_OPT_SWITCH: When the switch is on, the TTI dynamic adjustment algorithm for admission CE-based BE services applies to the UE with the UL enhanced L2 feature. This parameter is valid when DRA_BASE_ADM_CE_BE_TTI_RECFG_SWITCH(DraSwitch) is set to ON. 3) DRA_BASE_ADM_CE_BE_TTI_RECFG_SWITCH: When the switch is on, the TTI dynamic adjustment algorithm is supported for admission CE-based BE services. 4) DRA_BASE_COVER_BE_TTI_L2_OPT_SWITCH: When the switch is on, the TTI dynamic adjustment algorithm for coverage-based BE services applies to the UE with the UL enhanced L2 feature. This parameter is valid when DRA_BASE_COVER_BE_TTI_RECFG_SWITCH(DraSwitch) is set to ON. 5) DRA_BASE_COVER_BE_TTI_RECFG_SWITCH: When the switch is on, the TTI dynamic adjustment algorithm is supported for coverage-based BE services. 6) DRA_BASE_RES_BE_TTI_L2_OPT_SWITCH: When the switch is on, the TTI dynamic adjustment algorithm for differentiation-based BE services applies to the UE with the UL enhanced L2 feature. This parameter is valid when DRA_BASE_RES_BE_TTI_RECFG_SWITCH(DraSwitch) is set to ON. 7) DRA_BASE_RES_BE_TTI_RECFG_SWITCH: When the switch is on, the TTI dynamic adjustment algorithm is supported for differentiation-based BE services. 8) DRA_DCCC_SWITCH: When the switch is on, the dynamic channel reconfiguration control algorithm is used for the RNC. 9) DRA_HSDPA_DL_FLOW_CONTROL_SWITCH: When the switch is on, flow control is enabled for HSDPA services in AM mode. 10) DRA_HSDPA_STATE_TRANS_SWITCH: When the switch is on, the status of the UE RRC that carrying HSDPA services can be changed to CELL_FACH at the RNC. If a PS BE service is carried over the HS-DSCH, the switch PS_BE_STATE_TRANS_SWITCH should be on simultaneously. If a PS real-time service is carried over the HS-DSCH, the switch PS_NON_BE_STATE_TRANS_SWITCH should be on simultaneously. 11) DRA_HSUPA_DCCC_SWITCH: When the switch is on, the DCCC algorithm is used for HSUPA. The DCCC switch must be also on before this switch takes effect. 12) DRA_HSUPA_STATE_TRANS_SWITCH: When the switch is on, the status of the UE RRC that carrying HSUPA services can be changed to CELL_FACH at the RNC. If a PS BE service is carried over the E-DCH, the switch PS_BE_STATE_TRANS_SWITCH should be on simultaneously. If a PS real-time service is carried over the

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E-DCH, the switch PS_NON_BE_STATE_TRANS_SWITCH should be on simultaneously. 13) DRA_IP_SERVICE_QOS_SWITCH: Switch of the algorithm for increasing the quality of subscribed services. When this parameter is set to ON, the service priority weight of the subscriber whose key parameters (IP Address, IP Port, and IP Protocol Type) match the specified ones can be adjusted. In this way, the QoS is improved. 14) DRA_PS_BE_STATE_TRANS_SWITCH: When the switch is on, UE RRC status transition (CELL_FACH/CELL_PCH/URA_PCH) is allowed at the RNC. 15) DRA_PS_NON_BE_STATE_TRANS_SWITCH: When the switch is on, the status of the UE RRC that carrying real-time services can be changed to CELL_FACH at the RNC. 16) DRA_R99_DL_FLOW_CONTROL_SWITCH: Under a poor radio environment, the QoS of high speed services drops considerably and the TX power is overly high. In this case, the RNC can set restrictions on certain transmission formats based on the transmission quality, thus lowering traffic speed and TX power. When the switch is on, the R99 downlink flow control function is enabled. 17) DRA_THROUGHPUT_DCCC_SWITCH: When the switch is on, the DCCC based on traffic statistics is supported over the DCH. 18) DRA_VOICE_SAVE_CE_SWITCH: when the switch is on, the TTI selection based on the voice service type (including VoIP and CS over HSPA) is supported when the service is initially established. 19) DRA_VOICE_TTI_RECFG_SWITCH: when the switch is on, the TTI adjustment based on the voice service type (including VoIP and CS over HSPA) is supported. GUI Value Range: DRA_AQM_SWITCH, DRA_BASE_ADM_CE_BE_TTI_L2_OPT_SWITCH, DRA_BASE_ADM_CE_BE_TTI_RECFG_SWITCH, DRA_BASE_COVER_BE_TTI_L2_OPT_SWITCH, DRA_BASE_COVER_BE_TTI_RECFG_SWITCH, DRA_BASE_RES_BE_TTI_L2_OPT_SWITCH, DRA_BASE_RES_BE_TTI_RECFG_SWITCH, DRA_DCCC_SWITCH, DRA_HSDPA_DL_FLOW_CONTROL_SWITCH, DRA_HSDPA_STATE_TRANS_SWITCH, DRA_HSUPA_DCCC_SWITCH, DRA_HSUPA_STATE_TRANS_SWITCH, DRA_IP_SERVICE_QOS_SWITCH, DRA_PS_BE_STATE_TRANS_SWITCH, DRA_PS_NON_BE_STATE_TRANS_SWITCH, DRA_R99_DL_FLOW_CONTROL_SWITCH, DRA_THROUGHPUT_DCCC_SWITCH, DRA_VOICE_SAVE_CE_SWITCH, DRA_VOICE_TTI_RECFG_SWITCH Actual Value Range: DRA_AQM_SWITCH, DRA_BASE_ADM_CE_BE_TTI_L2_OPT_SWITCH,

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DRA_BASE_ADM_CE_BE_TTI_RECFG_SWITCH, DRA_BASE_COVER_BE_TTI_L2_OPT_SWITCH, DRA_BASE_COVER_BE_TTI_RECFG_SWITCH, DRA_BASE_RES_BE_TTI_L2_OPT_SWITCH, DRA_BASE_RES_BE_TTI_RECFG_SWITCH, DRA_DCCC_SWITCH, DRA_HSDPA_DL_FLOW_CONTROL_SWITCH, DRA_HSDPA_STATE_TRANS_SWITCH, DRA_HSUPA_DCCC_SWITCH, DRA_HSUPA_STATE_TRANS_SWITCH, DRA_IP_SERVICE_QOS_SWITCH, DRA_PS_BE_STATE_TRANS_SWITCH, DRA_PS_NON_BE_STATE_TRANS_SWITCH, DRA_R99_DL_FLOW_CONTROL_SWITCH, DRA_THROUGHPUT_DCCC_SWITCH, DRA_VOICE_SAVE_CE_SWITCH, DRA_VOICE_TTI_RECFG_SWITCH Unit: None Default Value: None

DRDEcN0Threshhold

BSC6900

ADD U2GNCELL(Optional) MOD U2GNCELL(Optional)

Meaning: DRD Ec/No threshold for determining whether to perform the blind handover. The DRD is permitted if Ec/No of the current cell is greater than the DRD Ec/No threshold of a inter-RAT/inter-frequency neighboring cell. GUI Value Range: -24~0 Actual Value Range: -24~0 Unit: dB Default Value: -18

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DrdOrLdrFlag

BSC6900

ADD UINTERFREQNCELL(Optional) MOD UINTERFREQNCELL(Optional)

Meaning: Specify the flags of the cells that the DRD measurement or LDR measurement is performed. The value "TRUE" indicates that the cell can be considered as the measurement object in the DRD measurement algorithm or LDR measurement algorithm. The value "FALSE" indicates that the cell is invalid. GUI Value Range: FALSE(Do not send), TRUE(Send) Actual Value Range: FALSE, TRUE Unit: None Default Value: False

DrSwitch BSC6900


Meaning: Direct retry switch group. 1) DR_RRC_DRD_SWITCH(DRD switch for RRC connection): When the switch is on, DRD and redirection is performed for RRC connection if retry is required. 2) DR_RAB_SING_DRD_SWITCH(DRD switch for single RAB): When the switch is on, DRD is performed for single service if retry is required. 3) DR_RAB_COMB_DRD_SWITCH(DRD switch for combine RAB): When the switch is on, DRD is performed for combined services if retry is required. GUI Value Range: DR_RRC_DRD_SWITCH, DR_RAB_SING_DRD_SWITCH, DR_RAB_COMB_DRD_SWITCH Actual Value Range: DR_RRC_DRD_SWITCH, DR_RAB_SING_DRD_SWITCH, DR_RAB_COMB_DRD_SWITCH Unit: None Default Value: None

EcN0EffectTime

BSC6900

ADD UCELLFRC(Optional) MOD UCELLFRC(Optional)

Meaning: Time duration when the reported Ec/No is valid. The reported Ec/No is valid for the period (starting from the time when the Ec/No report is received) specified by this parameter. GUI Value Range: 0~65535 Actual Value Range: 0~65535 Unit: ms Default Value: 5000

EcN0Ths BSC6900

ADD UCELLFRC(Optional) MOD UCELLFRC(Optional)

Meaning: Threshold for determining the signal quality in a cell. If the reported Ec/No exceeds the value of this parameter, you can infer that the signal quality in the cell is good and a high code rate can be set for initial access. GUI Value Range: 0~49 Actual Value Range: -24.5~0, step: 0.5 Unit: dB Default Value: 41

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EcN0Ths BSC6900

SET UFRC(Optional)

Meaning: Threshold for determining the signal quality in a cell. If the reported Ec/No exceeds the value of this parameter, you can infer that the signal quality in the cell is good and a high code rate can be set for initial access. GUI Value Range: 0~49 Actual Value Range: -24.5~0, step:0.5 Unit: dB Default Value: 41

EmcPreeRefVulnSwitch

BSC6900

SET UQUEUEPREEMPT(Optional)

Meaning: When the switch is enabled, users attempting emergency call can preempt the resources from all the accessed users for non emergency call. When the switch is disabled, users attempting emergency call can only preempt resources from the users for non emergency call when they are configured with the preempted attributes and ARP information element. GUI Value Range: OFF, ON Actual Value Range: OFF, ON Unit: None Default Value: ON

FACHPwrReduceValue

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Meaning: This parameter defines the reduce value in reducing FACH power Action. GUI Value Range: 0~30 Actual Value Range: 0~3, step:0.1 Unit: dB Default Value: 0

GoldUserLoadControlSwitch

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Meaning: Indicates whether gold users involve in the switch of congestion control. According to the policy set for gold users by operators, if service quality of gold users should be guaranteed even in resource congestion, the switch should be disabled. If the switch is enabled, LDR such as rate reduction and handover also occurs on gold users even in cell resource congestion, which impacts user service quality. If the switch is disabled, no action is performed on gold users. GUI Value Range: OFF(OFF), ON(ON) Actual Value Range: OFF, ON Unit: None Default Value: OFF

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HoSwitch BSC6900


Meaning: HandOver switch group. 1) HO_ALGO_HCS_SPEED_EST_SWITCH: When the switch is on, the RNC evaluates the UE's moving speed in the HCS and initiates fast intra-layer or slow inter-layer handover. 2) HO_ALGO_LDR_ALLOW_SHO_SWITCH: When the switch is on, the LDR inter-frequency handover is allowed during soft handover. 3) HO_ALGO_MBMS_FLC_SWITCH: When the switch is on, the UE requires that the redirection strategy be used for frequency layer convergence. 4) HO_ALGO_OVERLAY_SWITCH: When the switch is on, the associated receiving and mobility algorithms of the overlay network are used. When the switch is not on, the associated algorithms are not used. Overlay network is an UTRAN network covering present network, it supports HSPA, MBMS and other new features. To satisfy new requirements of operator and restrictions of present network, overlay network realizes operation distribution and load sharing between new network and present network, also gives special handling for mobility management of network verge. 5) HO_INTER_FREQ_HARD_HO_SWITCH: When the switch is on, the RNC is allowed to initiate inter-frequency measure control or the load-based inter-frequency hard handover upon the handover decision on inter-frequency load. 6) HO_INTER_RAT_CS_OUT_SWITCH: When the switch is on, the RNC is allowed to initiate inter-frequency measure control and the CS inter-RAT hard handover from the 3G network to the 2G network. 7) HO_INTER_RAT_PS_3G2G_CELLCHG_NACC_SWITCH: When the switch is on, the NACC function is supported during the PS inter-RAT handover from the 3G network to the 2G network in the cell change order process. When the switch is not on, the NACC function is not supported. When PS_3G2G_RELOCATION_SWITCH is ON, this switch is useless. When the NACC function is supported, the UE skips the reading procedure as the SI/PSI of the target cell is provided after the UE accesses the 2G cell. Thus, the delay of inter-cell handover is reduced. 8) HO_INTER_RAT_PS_3G2G_RELOCATION_SWITCH: When the switch is on, the PS inter-RAT handover from the 3G network to the 2G network is performed in the relocation process. When the switch is not on, the PS inter-RAT handover from the 3G network to the 2G network is performed in the cell change order process. 9) HO_INTER_RAT_PS_OUT_SWITCH: When the switch is on, the RNC is allowed to initiate inter-frequency measure control and the PS inter-RAT hard handover from the 3G network to the 2G network. 10) HO_INTER_RAT_RNC_SERVICE_HO_SWITCH: When the switch is on, the attributes of inter-RAT handover of the services are based on the configuration of RNC parameters. When the switch is not on, the attributes are set on the basis of the CN. If no information is provided by the CN, the attributes

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are then based on the RNC parameters. 11) HO_INTRA_FREQ_DETSET_INTO_ACTSET_SWITCH: When the switch is on, the cells in the detected set from which the RNC receives their valid event reports can be added to the active set. The cells allowed to be added to the active set must be the neighboring cells of the cells in the active set. 12) HO_INTRA_FREQ_DETSET_RPRT_SWITCH: When the switch is on, statistics on the intra-frequency measurement reports of the detected set are taken. 13) HO_INTRA_FREQ_HARD_HO_SWITCH: When the switch is on, the RNC is allowed to initiate the intra-frequency hard handover. 14) HO_INTRA_FREQ_RPRT_1J_SWITCH: When the switch is on, the event 1J is included in the delivery of intra-frequency measurement control if the UE version is R6. 15) HO_INTRA_FREQ_SOFT_HO_SWITCH: When the switch is on, the cells on the RNC can active the soft handover. When the RNC receives reports on the events 1A, 1B, 1C, or 1D, associated addition, removal, and replacement of handover cell of the soft handover are initiated. 16) HO_MC_MEAS_BEYOND_UE_CAP_SWITCH: When the switch is on, the neighboring cell whose frequency band is beyond the UE's capabilities can also be delivered in the inter-frequency measurement list. 17) HO_MC_NCELL_COMBINE_SWITCH: When the switch is on, the neighboring cell combined algorithm is used during the delivery of the objects to be measured. When the switch is not on, the optimal cell algorithm is used. 18) HO_MC_SIGNAL_IUR_INTRA_SWITCH: When the switch is on, intra-frequency handover is allowed over the Iur interface if the UE has only signaling. 19) HO_MC_SIGNAL_SWITCH: When the switch is on, quality measurement on the active set is delivered after signaling setup but before service setup. If the UE is at the cell verge or receives weak signals after accessing the network, the RNC can trigger inter-frequency or inter-RAT handover when the UE sets up the RRC. 20) HO_MC_SNA_RESTRICTION_SWITCH: When the switch is on, the RNC controls the UEs in the connected state based on the configurations on the CN. The UEs can only access and move in authorized cells. GUI Value Range: HO_ALGO_HCS_SPEED_EST_SWITCH, HO_ALGO_LDR_ALLOW_SHO_SWITCH, HO_ALGO_MBMS_FLC_SWITCH, HO_ALGO_OVERLAY_SWITCH, HO_INTER_FREQ_HARD_HO_SWITCH, HO_INTER_RAT_CS_OUT_SWITCH, HO_INTER_RAT_PS_3G2G_CELLCHG_NACC_SWITCH, HO_INTER_RAT_PS_3G2G_RELOCATION_SWITCH, HO_INTER_RAT_PS_OUT_SWITCH, HO_INTER_RAT_RNC_SERVICE_HO_SWITCH, HO_INTRA_FREQ_DETSET_INTO_ACTSET_SWITCH,

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HO_INTRA_FREQ_DETSET_RPRT_SWITCH, HO_INTRA_FREQ_HARD_HO_SWITCH, HO_INTRA_FREQ_RPRT_1J_SWITCH, HO_INTRA_FREQ_SOFT_HO_SWITCH, HO_MC_MEAS_BEYOND_UE_CAP_SWITCH, HO_MC_NCELL_COMBINE_SWITCH, HO_MC_SIGNAL_IUR_INTRA_SWITCH, HO_MC_SIGNAL_SWITCH, HO_MC_SNA_RESTRICTION_SWITCH Actual Value Range: HO_ALGO_HCS_SPEED_EST_SWITCH, HO_ALGO_LDR_ALLOW_SHO_SWITCH, HO_ALGO_MBMS_FLC_SWITCH, HO_ALGO_OVERLAY_SWITCH, HO_INTER_FREQ_HARD_HO_SWITCH, HO_INTER_RAT_CS_OUT_SWITCH, HO_INTER_RAT_PS_3G2G_CELLCHG_NACC_SWITCH, HO_INTER_RAT_PS_3G2G_RELOCATION_SWITCH, HO_INTER_RAT_PS_OUT_SWITCH, HO_INTER_RAT_RNC_SERVICE_HO_SWITCH, HO_INTRA_FREQ_DETSET_INTO_ACTSET_SWITCH, HO_INTRA_FREQ_DETSET_RPRT_SWITCH, HO_INTRA_FREQ_HARD_HO_SWITCH, HO_INTRA_FREQ_RPRT_1J_SWITCH, HO_INTRA_FREQ_SOFT_HO_SWITCH, HO_MC_MEAS_BEYOND_UE_CAP_SWITCH, HO_MC_NCELL_COMBINE_SWITCH, HO_MC_SIGNAL_IUR_INTRA_SWITCH, HO_MC_SIGNAL_SWITCH, HO_MC_SNA_RESTRICTION_SWITCH Unit: None Default Value: None

HsdpaCMPermissionInd

BSC6900

SET UCMCF(Optional)

Meaning: Whether the compressed mode (CM) can coexist with the HSDPA service. If this parameter is set to TRUE: 1. the RNC can enable the CM for HSDPA services. 2. The HSDPA services can be enabled when the CM is enabled. If this parameter is set to FALSE: 1. the CM for HSDPA services can be enabled only after the H2D (HS-DSCH to DCH) channel switch. 2. The HSDPA services cannot be enabled when the CM is enabled. This switch is used for the compatibility of the HSDPA terminals that do not support CM when HSDPA is enabled. GUI Value Range: FALSE(Forbidden), TRUE(Permit) Actual Value Range: FALSE, TRUE Unit: None Default Value: True

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HsdpaNeedPwrFilterLen

BSC6900

SET ULDM(Optional)

Meaning: Length of smoothing filter window of HSDPA power requirement. GUI Value Range: 1~32 Actual Value Range: 1~32 Unit: None Default Value: 5

HsdpaPrvidBitRateFilterLen

BSC6900

SET ULDM(Optional)

Meaning: Length of smoothing filter window of HSDPA bit rate. GUI Value Range: 1~32 Actual Value Range: 1~32 Unit: None Default Value: 5

HsupaCMPermissionInd

BSC6900

SET UCMCF(Optional)

Meaning: Whether the compressed mode (CM) can coexist with the HSUPA service. If this parameter is set to Permit: 1. the RNC can enable the CM for HSUPA services. 2. The HSUPA services can be enabled when the CM is enabled. If this parameter is set to Limited: 1. the CM for HSUPA services can be enabled only after the E2D (E-DCH to DCH) channel switch. 2. The HSUPA services cannot be enabled when the CM is enabled. If this parameter is set to BasedonUECap, the RNC determines whether CM can be enabled for HSUPA services and whether HSUPA services can be enabled when the CM is enabled by considering the UE capability. This switch is used for the compatibility of the HSUPA terminals that do not support CM when HSUPA is enabled. GUI Value Range: Limited, Permit, BasedOnUECap(Based On UE Capability) Actual Value Range: Limited, Permit, BasedOnUECap Unit: None Default Value: BasedOnUECap

HsupaInitialRate

BSC6900

SET UFRC(Optional)

Meaning: HSUPA BE traffic initial bit rate. When DCCC algorithm switch and HSUPA DCCC algorithm switch are enabled, the uplink initial bit rate will be set to this value if the uplink max bit rate is higher than the initial bit rate. GUI Value Range: D8, D16, D32, D64, D128, D144, D256, D384, D608, D1280, D2048, D2720, D5440 Actual Value Range: 8, 16, 32, 64, 128, 144, 256, 384, 608, 1280, 2048, 2720, 5440 Unit: kbit/s Default Value: D256

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HsupaPrvidBitRateFilterLen

BSC6900

SET ULDM(Optional)

Meaning: Length of smoothing filter window of HSUPA bit rate. GUI Value Range: 1~32 Actual Value Range: 1~32 Unit: None Default Value: 5

InterFreqLdHoForbidenTC

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Meaning: This parameter specifies the forbidden traffic classes when perform inter-frequency handover, in order to prevent disarranging of the layers. GUI Value Range: R99_CONVERSATIONAL(R99 Conversational), R99_STREAMING(R99 Streaming), R99_BE(R99 BE), HSDPA_CONVERSATIONAL(HSDPA Conversational), HSDPA_STREAMING(HSDPA Streaming), HSDPA_BE(HSDPA BE), HSPA_CONVERSATIONAL(HSPA Conversational), HSPA_STREAMING(HSPA Streaming), HSPA_BE(HSPA BE) Actual Value Range: R99_CONVERSATIONAL, R99_STREAMING, R99_BE, HSDPA_CONVERSATIONAL, HSDPA_STREAMING, HSDPA_BE, HSPA_CONVERSATIONAL, HSPA_STREAMING, HSPA_BE Unit: None Default Value: None

InterFreqLDHOMethodSelection

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Meaning: This parameter specifies load handover method.When network is composed of same frequency band,Blind Handover method is suggested .Otherwise,Measure handover is suggested . GUI Value Range: BLINDHO(BLINDHO), MEASUREHO(MEASUREHO) Actual Value Range: BLINDHO, MEASUREHO Unit: None Default Value: BLINDHO

InterFreqMeasTime

BSC6900

ADD UCELLINTERFREQHOCOV(Optional) MOD UCELLINTERFREQHOCOV(Optional)

Meaning: Length of the timer for the inter-frequency measurement. If the inter-frequency handover is not performed before this timer expires, the inter-frequency measurement is stopped and the compression mode is disabled (if enabled before). The value 0 indicates that this timer is not to be started. This parameter is used to prevent the long duration of the inter-frequency measurement state (compression mode) due to unavailability of a target cell that meets the handover criteria. GUI Value Range: 0~512 Actual Value Range: 0~512 Unit: s Default Value: 60

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InterFreqMeasTime

BSC6900

ADD UCELLMCLDR(Optional) MOD UCELLMCLDR(Optional)

Meaning: This parameter defines the timer length for inter-frequency measurement. After inter-frequency measurement starts, if no inter-frequency handover is performed when this timer expires, the inter-frequency measurement and the compressed mode (if started) are stopped. This parameter is used to prevent the long inter-frequency measurement state (compressed mode) due to unavailable measurement of the target cells that meet the handover requirements. GUI Value Range: 1~255 Actual Value Range: 1~255 Unit: s Default Value: 6

LdbAvgFilterLen

BSC6900

SET ULDM(Optional)

Meaning: Length of smoothing filter window of intra-frequency load balancing (LDB). GUI Value Range: 1~32 Actual Value Range: 1~32 Unit: None Default Value: 6

LdrCodePriUseInd

BSC6900


Meaning: FALSE means not considering the code priority during the code reshuffling. TRUE means considering the code priority during the code reshuffling. If the parameter is TRUE, the codes with high priority are reserved during the code reshuffling. It is good for the code resource dynamic sharing, which is a function used for the HSDPA service. GUI Value Range: FALSE(FALSE), TRUE(TRUE) Actual Value Range: FALSE, TRUE Unit: None Default Value: False

LdrCodeUsedSpaceThd

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Meaning: Code resource usage difference threshold. Inter-frequency handover is triggered when the difference of the resource usage of the current cell and that of the target cell is greater than this threshold. GUI Value Range: 0~100 Actual Value Range: 0~1, step:0.01 Unit: % Default Value: 13

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LdrPeriodTimerLen

BSC6900

SET ULDCPERIOD(Optional)

Meaning: Identifying the period of the LDR execution. When basic congestion occurs, execution of LDR can dynamically reduce the cell load. The lower the parameter value is, the more frequently the LDR action is executed, which decreases the load quickly. If the parameter value is excessively low, an LDR action may overlap the previous one before the previous result is displayed in LDM. The higher the parameter value is, the more likely this problem can be prevented. If the parameter value is excessively high, the LDR action may be executed rarely, failing to lower the load timely. The LDR algorithm aims to slowly reduce the cell load and control the load below the admission threshold, each LDR action takes a period (for example the inter-RAT load handover needs a delay of about 5 s if the compressed mode is needed), and there is a delay for the LDM module responds to the load decreasing (the delay is about 3 s when the L3 filter coefficient is set to 6), so the parameter value should be higher than 8s. GUI Value Range: 1~86400 Actual Value Range: 1~86400 Unit: s Default Value: 10

MaxFachPower

BSC6900

ADD UFACH(Optional)

Meaning: The offset between the FACH transmit power and P-CPICH transmit power in a cell. GUI Value Range: -350~150 Actual Value Range: -35~15, step: 0.1 Unit: dB Default Value: 10

MaxQueueTimeLen

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Meaning: Maximum queue time of users. When a user initiates a call, it joins the queue due to cell resource insufficiency. This parameter defines the maximum length of time required for queuing of a user. If cell resources are still insufficient after expiration, access fails. GUI Value Range: 1~60 Actual Value Range: 1~60, step:1 Unit: s Default Value: 5

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MaxUserNumCodeAdj

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Meaning: This parameter specifies the number of users selected in code reshuffling. Code reshuffling can be triggered only when the number of users on a code is no greater than the threshold. Code reshuffling has a big impact on the QoS. In addition, the reshuffled subscribers occupy two code resources during code reshuffling. Thus, the parameter should be set to a comparatively low value. GUI Value Range: 1~3 Actual Value Range: 1~3 Unit: None Default Value: 1

MbmsDecPowerRabThd

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Meaning: When the priority of the RAB of MBMS services exceeds this threshold, reconfigure the MBMS power to the minimum power. The MBMS service at each rate is set on the basis of two power levels. The power set for an MBMS service is determined according to cell load during the service access. In addition, the FACH power of the MBMS service must be decreased as required in the duration of cell congestion. Some services with high priority, for example the disaster pre-alert, however, do not need the coverage shrink caused by cell load. In such a case, you can adjust the service priority threshold to protect the services with high priority against the impact of the service access failure and the load control algorithm. GUI Value Range: 1~15 Actual Value Range: 1~15 Unit: None Default Value: 1

MbmsOlcRelNum

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ADD UCELLOLC(Optional)

Meaning: MBMS service release is an extreme method in reducing the cell load and recovering the system when the cell is overloaded and congested. The mechanism of the OLC is that an action is performed in each [OLC period] and some services are selected based on the action rules to perform this action. This parameter defines the maximum number of MBMS services released in executing downlink OLC service release. GUI Value Range: 0~8 Actual Value Range: 0~8 Unit: None Default Value: 1

MinForDlBasicMeas

BSC6900

SET ULDM(Mandatory)

Meaning: DL basic common measurement report cycle. For detailed information of this parameter, refer to 3GPP TS 25.433. GUI Value Range: 1~60 Actual Value Range: 1~60 Unit: min

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Default Value: 20

MinForHsdpaPrvidRateMeas

BSC6900

SET ULDM(Mandatory)

Meaning: This parameter specifies the HSDPA bit rate measurement report period. For detailed information of this parameter, refer to 3GPP TS 25.433. GUI Value Range: 1~60 Actual Value Range: 1~60 Unit: min Default Value: 10

MinForHsdpaPwrMeas

BSC6900

SET ULDM(Mandatory)

Meaning: HSDPA power requirement measurement report period For detailed information of this parameter, refer to 3GPP TS 25.433. GUI Value Range: 1~60 Actual Value Range: 1~60 Unit: min Default Value: 10

MinForHsupaPrvidRateMeas

BSC6900

SET ULDM(Mandatory)

Meaning: This parameter specifies the HSUPA bit rate measurement report period. For detailed information of this parameter, refer to 3GPP TS 25.433. GUI Value Range: 1~60 Actual Value Range: 1~60 Unit: min Default Value: 1

MinForUlBasicMeas

BSC6900

SET ULDM(Mandatory)

Meaning: UL basic common measurement report cycle. For detailed information of this parameter, refer to 3GPP TS 25.433. GUI Value Range: 1~60 Actual Value Range: 1~60 Unit: min Default Value: 20

MinPCPICHPower

BSC6900

ADD UPCPICH(Optional)

Meaning: Minimum TX power of the PCPICH in a cell. This parameter should be set based on the actual system environment such as cell coverage (radius) and geographical environment. Ensure that MinPCPICHPower is set under the condition of a proper proportion of soft handover area, or under the condition that no coverage hole exists. GUI Value Range: -100~500 Actual Value Range: -10~50, step: 0.1 Unit: dBm

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Default Value: 313

NBMCacAlgoSwitch

BSC6900

ADD UCELLALGOSWITCH(Optional) MOD UCELLALGOSWITCH(Optional)

Meaning: "The above values of the algorithms represent the following information: CRD_ADCTRL: Control Cell Credit admission control algorithm Only when NODEB_CREDIT_CAC_SWITCH which is set by the SET UCACALGOSWITCH command and this switch are on,the Cell Credit admission control algorithm is valid. HSDPA_UU_ADCTRL: Control HSDPA UU Load admission control algorithm HSDPA_GBP_MEAS: Control HSDPA HS-DSCH Required Power measurement HSDPA_PBR_MEAS: Control HSDPA HS-DSCH Provided Bit Rate measurement HSUPA_UU_ADCTRL: Control HSUPA UU Load admission control algorithm MBMS_UU_ADCTRL: Control MBMS UU Load admission control algorithm HSUPA_PBR_MEAS: Control HSUPA Provided Bit Rate measurement HSUPA_EDCH_RSEPS_MEAS: Control HSUPA Provided Received Scheduled EDCH Power Share measurement EMC_UU_ADCTRL: Control power admission for emergency user RTWP_RESIST_DISTURB: Control algorithm of resisting disturb when RTWP is abnormal FACH_UU_ADCTRL: The switch for resource admission to the FACH over the Uu interface (FACH_UU_ADCTRL) is used to enable or disable the user admission function to FACH. 1. If this switch is enabled: if the current cell is congested due to overload, and the users are with RAB connection requests or RRC connection requests(except the cause of ""Detach"", ""Registration"", or ""Emergency Call""), the users will be rejected. Otherwise FACH user admission procedure is initiated. A user can access the cell after the procedure succeeds. 2. If this switch is disabled: FACH user admission procedure is initiated without the consideration of cell state. MIMOCELL_LEGACYHSDPA_ADCTRL: Legacy HSDPA admission control algorithm in MIMO cell. FAST_DORMANCY_ADCTRL: Whether to enable or disable state transition of users in the CELL-DCH state, who are enabled with fast dormancy, to ease FACH congestion in a

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cell. If this switch is turned off in a cell, state transition of such users is disabled. Note that when this switch is turned off in multiple cells under an RNC, signaling storm may occur. As a result, the CPU usage of the RNC, NodeB, and SGSN increases greatly, leading to service setup failure. If switches above are selected, the corresponding algorithms will be enabled; otherwise, disabled." GUI Value Range: CRD_ADCTRL(Credit Admission Control Algorithm), HSDPA_UU_ADCTRL(HSDPA UU Load Admission Control Algorithm), HSUPA_UU_ADCTRL(HSUPA UU Load Admission Control Algorithm), MBMS_UU_ADCTRL(MBMS UU Load Admission Control Algorithm), HSDPA_GBP_MEAS(HSDPA GBP Meas Algorithm), HSDPA_PBR_MEAS(HSDPA PBR Meas Algorithm), HSUPA_PBR_MEAS(HSUPA PBR Meas Algorithm), HSUPA_EDCH_RSEPS_MEAS(HSUPA EDCH RSEPS Meas Algorithm), EMC_UU_ADCTRL(emergency call power admission), RTWP_RESIST_DISTURB(RTWP Resist Disturb Switch), FACH_UU_ADCTRL(FACH power cac switch), MIMOCELL_LEGACYHSDPA_ADCTRL(Legacy HSDPA Admission Control Algorithm in MIMO Cell), FAST_DORMANCY_ADCTRL(Fast Dormancy User Admission Control Algorithm) Actual Value Range: CRD_ADCTRL, HSDPA_UU_ADCTRL, HSUPA_UU_ADCTRL, MBMS_UU_ADCTRL, HSDPA_GBP_MEAS, HSDPA_PBR_MEAS, HSUPA_PBR_MEAS, HSUPA_EDCH_RSEPS_MEAS, EMC_UU_ADCTRL, RTWP_RESIST_DISTURB, FACH_UU_ADCTRL, MIMOCELL_LEGACYHSDPA_ADCTRL, FAST_DORMANCY_ADCTRL Unit: None Default Value: None

NBMDlCacAlgoSelSwitch

BSC6900

ADD UCELLALGOSWITCH(Mandatory) MOD UCELLALGOSWITCH(Optional)

Meaning: The algorithms with the above values represent are as follow: ALGORITHM_OFF: Disable downlink call admission control algorithm. ALGORITHM_FIRST: The load factor prediction algorithm will be used in downlink CAC. ALGORITHM_SECOND: The equivalent user number algorithm will be used in downlink CAC. ALGORITHM_THIRD: The loose call admission control algorithm will be used in downlink CAC. GUI Value Range: ALGORITHM_OFF, ALGORITHM_FIRST, ALGORITHM_SECOND, ALGORITHM_THIRD Actual Value Range: ALGORITHM_OFF, ALGORITHM_FIRST, ALGORITHM_SECOND, ALGORITHM_THIRD Unit: None

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Default Value: None

NBMLdcAlgoSwitch

BSC6900


Meaning: The algorithms with the above values represent are as follow: INTRA_FREQUENCY_LDB: Intra-frequency load balance algorithm. It is also named cell breathing algorithm.Based on the cell load, this algorithm changes the pilot power of the cell to control the load between intra-frequency cells. PUC: Potential user control algorithm. Based on the cell load, this algorithm changes the selection/reselection parameters of a cell to lead the UE to a lighter loaded cell. UL_UU_OLC: UL UU overload congestion control algorithm. When the cell is overloaded in UL, this algorithm reduces the cell load in UL by quick TF restriction or UE release. DL_UU_OLC: DL UU overload congestion control algorithm. When the cell is overloaded in DL, this algorithm reduces the cell load in DL by quick TF restriction or UE release. UL_UU_LDR: UL UU load reshuffling algorithm. When the cell is heavily loaded in UL, this algorithm reduces the cell load in UL by using inter-frequency load handover, BE service rate reduction, uncontrollable real-time service QoS renegotiation, CS should be inter-RAT, PS should be inter-RAT handover, CS should not be inter-RATand, PS should not be inter-RAT handover and AMR service rate reduction. DL_UU_LDR: DL UU load reshuffling algorithm. When the cell is heavily loaded in DL, this algorithm reduces the cell load in DL by using inter-frequency load handover, BE service rate reduction, uncontrollable real-time service QoS renegotiation, CS should be inter-RAT, PS should be inter-RAT handover, CS should not be inter-RATand, PS should not be inter-RAT handover, AMR service rate reduction and MBMS service power decrease. OLC_EVENTMEAS: Control OLC event measurement. This algorithm starts the OLC event measurement. CELL_CODE_LDR: Code reshuffling algorithm. When the cell CODE is heavily loaded, this algorithm reduces the cell CODE load by using BE service rate reduction and code tree

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reshuffling. CELL_CREDIT_LDR:Credit reshuffling algorithm. When the cell credit is heavily loaded, this algorithm reduces the credit load of the cell by using BE service rate reduction, uncontrollable real-time service QoS renegotiation, CS should be inter-RAT, PS should be inter-RAT handover, CS should not be inter-RATand and PS should not be inter-RAT handover. If INTRA_FREQUENCY_LDB, PUC, ULOLC, DLOLC, ULLDR, UDLLDR, OLC_EVENTMEAS, CELL_CODE_LDR and CELL_CREDIT_LDR are selected, the corresponding algorithms will be enabled; otherwise, disabled. GUI Value Range: INTRA_FREQUENCY_LDB(Intra Frequency LDB Algorithm), PUC(Potential User Control Algorithm), UL_UU_LDR(Uplink UU LDR Algorithm), DL_UU_LDR(Downlink UU LDR Algorithm), UL_UU_OLC(Uplink UU OLC Algorithm), DL_UU_OLC(Downlink UU OLC Algorithm), OLC_EVENTMEAS(OLC Event Meas Algorithm), CELL_CODE_LDR(Code LDR Algorithm), CELL_CREDIT_LDR(Credit LDR Algorithm) Actual Value Range: INTRA_FREQUENCY_LDB, PUC, UL_UU_LDR, DL_UU_LDR, UL_UU_OLC, DL_UU_OLC, OLC_EVENTMEAS, CELL_CODE_LDR, CELL_CREDIT_LDR Unit: None Default Value: None

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NbmLdcUeSelSwitch

BSC6900


Meaning: The algorithms with the above values represent are as follow: NBM_LDC_ALL_UE: When inter-freq handover select user occurs, no need to consider whether target cell support Ue. NBM_LDC_MATCH_UE_ONLY: When inter-freq handover select user occurs, only consider Ues supported by target cell. NBM_LDC_MATCH_UE_FIRST: When inter-freq handover select user occurs, first consider Ues supported by target cell. GUI Value Range: NBM_LDC_ALL_UE(Select all users), NBM_LDC_MATCH_UE_ONLY(Select users match target cell support only), NBM_LDC_MATCH_UE_FIRST(Select users match target cell support first) Actual Value Range: NBM_LDC_ALL_UE, NBM_LDC_MATCH_UE_ONLY, NBM_LDC_MATCH_UE_FIRST Unit: None Default Value: NBM_LDC_MATCH_UE_ONLY

NBMUlCacAlgoSelSwitch

BSC6900

ADD UCELLALGOSWITCH(Mandatory) MOD UCELLALGOSWITCH(Optional)

Meaning: The algorithms with the above values represent are as follow: ALGORITHM_OFF: Disable uplink call admission control algorithm. ALGORITHM_FIRST: The load factor prediction algorithm will be used in uplink CAC. ALGORITHM_SECOND: The equivalent user number algorithm will be used in uplink CAC. ALGORITHM_THIRD: The loose call admission control algorithm will be used in uplink CAC. GUI Value Range: ALGORITHM_OFF, ALGORITHM_FIRST, ALGORITHM_SECOND, ALGORITHM_THIRD Actual Value Range: ALGORITHM_OFF, ALGORITHM_FIRST, ALGORITHM_SECOND, ALGORITHM_THIRD Unit: None Default Value: None

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NodeBLdcAlgoSwitch

BSC6900

ADD UNODEBALGOPARA(Optional) MOD UNODEBALGOPARA(Optional)

Meaning: IUB_LDR (Iub congestion control algorithm): When the NodeB Iub load is heavy, users are assembled in priority order among all the NodeBs and some users are selected for LDR action (such as BE service rate reduction) in order to reduce the NodeB Iub load. NODEB_CREDIT_LDR (NodeB level credit congestion control algorithm): When the NodeB level credit load is heavy, users are assembled in priority order among all the NodeBs and some users are selected for LDR action in order to reduce the NodeB level credit load. LCG_CREDIT_LDR (Cell group level credit congestion control algorithm): When the cell group level credit load is heavy, users are assembled in priority order among all the NodeBs and some users are selected for LDR action in order to reduce the cell group level credit load. IUB_OLC (Iub Overload congestion control algorithm): When the NodeB Iub load is Overload, users are assembled in priority order among all the NodeBs and some users are selected for Olc action in order to reduce the NodeB Iub load. To enable some of the algorithms above, select them. Otherwise, they are disabled. GUI Value Range: IUB_LDR(IUB LDR Algorithm), NODEB_CREDIT_LDR(NodeB Credit LDR Algorithm), LCG_CREDIT_LDR(LCG Credit LDR Algorithm), IUB_OLC(IUB OLC Algorithm) Actual Value Range: IUB_LDR, NODEB_CREDIT_LDR, LCG_CREDIT_LDR, IUB_OLC Unit: None Default Value: None

OffQoffset1Heavy

BSC6900

ADD UCELLPUC(Optional) MOD UCELLPUC(Optional)

Meaning: Offset of Qoffset1 when neighboring cell load is heavier than that of the center cell (Note: Qoffset1 is used as a priority to decide which cell will be selected in cell selection or reselection) For detailed information of this parameter, refer to 3GPP TS 25.304. GUI Value Range: -20~20 Actual Value Range: -20~20 Unit: dB Default Value: 4

OffQoffset1Light

BSC6900


Meaning: Offset of Qoffset1 when neighboring cell load is lighter than that of the center cell (Note: Qoffset1 is used as a priority to decide which cell will be selected in cell selection or reselection) For detailed information of this parameter, refer to 3GPP TS 25.304. GUI Value Range: -20~20 Actual Value Range: -20~20 Unit: dB Default Value: -4

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OffQoffset2Heavy

BSC6900


Meaning: Offset of Qoffset2 when neighboring cell load is heavier than that of the center cell (Note: Qoffset2 is used as a priority to decide which cell will be selected in cell selection or reselection) For detailed information of this parameter, refer to 3GPP TS 25.304. GUI Value Range: -20~20 Actual Value Range: -20~20 Unit: dB Default Value: 4

OffQoffset2Light

BSC6900


Meaning: Offset of Qoffset2 when neighboring cell load is lighter than that of the center cell (Note: Qoffset2 is used as a priority to decide which cell will be selected in cell selection or reselection) For detailed information of this parameter, refer to 3GPP TS 25.304. GUI Value Range: -20~20 Actual Value Range: -20~20 Unit: dB Default Value: -4

OffSinterHeavy

BSC6900


Meaning: Offset of Sintersearch when center cell load level is "Heavy" (Note: Sintersearch is used to decide whether to start the inter-frequency cell reselection). For detailed information of this parameter, refer to 3GPP TS 25.304. GUI Value Range: -10~10 Actual Value Range: -20~20, step:2 Unit: dB Default Value: 2

OffSinterLight

BSC6900


Meaning: Offset of Sintersearch when center cell load level is "Light" (Note: Sintersearch is used to decide whether to start the inter-frequency cell reselection). For detailed information of this parameter, refer to 3GPP TS 25.304. GUI Value Range: -10~10 Actual Value Range: -20~20, step:2 Unit: dB Default Value: -2

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OlcPeriodTimerLen

BSC6900

SET ULDCPERIOD(Optional)

Meaning: Identifying the period of the OLC execution. When overload occurs, execution of OLC can dynamically reduce the cell load. When setting the parameter, consider the hysteresis for which the load monitoring responds to the load change. For example, when the layer 3 filter coefficient is 6, the hysteresis for which the load measurement responds to the step-function signals is about 2.8s, namely that the system can trace the load control effect about 3 s later after each load control. In this case, the OLC period timer length cannot be smaller than 3s. OlcPeriodTimerLen along with ULOLCFTFRstrctUserNum, DLOLCFTFRstrctUserNum, ULOLCFTFRSTRCTTimes, DLOLCFTFRSTRCTTimes, ULOLCTraffRelUserNum, and DLOLCTraffRelUserNum determine the time it takes to release the uplink/downlink overload. If the OLC period is excessively long, the system may respond very slowly to overload. If the OLC period is excessively short, unnecessary adjustment may occur before the previous OLC action has taken effect, and therefore the system performance is affected. GUI Value Range: 100~86400000 Actual Value Range: 100~86400000 Unit: ms Default Value: 3000

PCPICHPowerPace

BSC6900


Meaning: Pilot power adjustment step increased or decreased in each increase of the cell breathing algorithm or decrease of cell pilot. For detailed information of this parameter, refer to 3GPP TS 25.433. GUI Value Range: 0~100 Actual Value Range: 0~10, step:0.1 Unit: dB Default Value: 2

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PollTimerLen BSC6900


Meaning: Timer length of the queue poll. The queue is polled for every time specified in this parameter. During each poll, all the expired users are removed from the queue and this user fails in access. Among all the unexpired users, resources are allocated in the order of high priority to low priority. If resource allocation is successful, the user succeeds in access and traverse of this queue is stopped. Otherwise, the rest users are traversed until all the unexpired users go through this. GUI Value Range: 1~80 Actual Value Range: 10~800, step:10 Unit: ms Default Value: 50

PrdReportInterval

BSC6900

ADD UCELLINTERFREQHOCOV(Optional) MOD UCELLINTERFREQHOCOV(Optional)

Meaning: Interval between periodic reporting for the inter-frequency handover. In periodic reporting mode, the inter-frequency handover attempts is reported at the preset interval. It is not recommended that this parameter be set to "NON_PERIODIC_REPORT" since the UE behavior may be unknown. This parameter has impact on the Uu signaling flow. If the interval is too short and the frequency is too high, the RNC may have high load when processing signaling. If the interval is too long, the network cannot detect the signal changes in time. This may delay the inter-frequency handover, thus causing call drops. GUI Value Range: NON_PERIODIC_REPORT(Non periodical reporting), D250~1 D500~2 D1000~3 D2000~4 D3000~5 D4000~6 D6000~7 D8000~8 D12000~9 D16000~10 D20000~11 D24000~12 D28000~13 D32000~14 D64000 Actual Value Range: NON_PERIODIC_REPORT, 250, 500, 1000, 2000, 3000, 4000, 6000, 8000, 12000, 16000, 20000, 24000, 28000, 32000, 64000 Unit: ms Default Value: D500

PreemptAlgoSwitch

BSC6900


Meaning: Determines whether preemption is supported. When this switch is enabled, the RNC allows privileged users or services to preempt cell resources from the users or services with the preempted attributes and lower priority in the case of cell resource insufficiency. When the switch is disabled, the RNC terminates the service for the user due to the failure in cell resource application. GUI Value Range: OFF, ON Actual Value Range: OFF, ON Unit: None Default Value: OFF

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PreemptRefArpSwitch

BSC6900


Meaning: Indicating whether ARP-based preemption between TCs is supported. This switch only has impact on the TC-based priorities. When the priority is based on the TC and the switch is enabled, for the following two situations, the preempting service should have a higher priority and ARP priority than the preempted service does: 1.The preempting service is the streaming service and the preempted service is the interactive or background service. 2. The preempting service is the interactive service and the preempted service is the background service. GUI Value Range: OFF, ON Actual Value Range: OFF, ON Unit: None Default Value: ON

PriorityReference

BSC6900

ADD UOPERUSERPRIORITY(Optional) MOD UOPERUSERPRIORITY(Optional)

Meaning: Reference used to determine which priority is arranged first in the priority sequence. If the ARP is preferably used, the priority sequence is gold > silver > copper. If the ARPs are all the same, the TrafficClass is used and the priority sequence is conversational > streaming > interactive > background. If the TrafficClass is preferably used, the priority sequence is conversational > streaming > interactive > background. If the TrafficClass factors are all the same, the ARP factor is used and the priority sequence is gold > silver > copper. GUI Value Range: ARP, TrafficClass Actual Value Range: ARP, TrafficClass Unit: None Default Value: ARP

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PsSwitch BSC6900


Meaning: PS rate negotiation switch group. 1) PS_BE_EXTRA_LOW_RATE_ACCESS_SWITCH: When the switch is on, access at a rate of 0 kbit/s or on the FACH is determined according to the current connection state of the RRC if the PS BE admission and the later preemption and queuing fail. 2) PS_BE_INIT_RATE_DYNAMIC_CFG_SWITCH: When the switch is on, the initial rate of the service should be dynamically configured according to the value of Ec/No reported by the UE when the PS BE service is established. 3) PS_BE_IU_QOS_NEG_SWITCH: When the switch is on, the Iu QoS Negotiation function is applied to the PS BE service if Alternative RAB Parameter Values IE is present in the RANAP RAB ASSIGNMENT REQUEST or RELOCATION REQUEST message. 4) PS_RAB_DOWNSIZING_SWITCH: When the switch is on and the RAB downsizing license is activated, the initial speed is determined on the basis of cell resources. Downsizing is implemented for BE services. 5) PS_STREAM_IU_QOS_NEG_SWITCH: When the switch is on, the Iu QoS Negotiation function is applied to the PS STREAM service if Alternative RAB Parameter Values IE is present in the RANAP RAB ASSIGNMENT REQUEST or RELOCATION REQUEST message. 6) PS_BE_STRICT_IU_QOS_NEG_SWITCH: When the switch is on, the strict Iu QoS Negotiation function is applied to the PS BE service,RNC select Iu max bit rate based on UE capacity,cell capacity,max bitrate and alternative RAB parameter values in RANAP RAB ASSIGNMENT REQUEST or RELOCATION REQUEST message. When the switch is not on, the loose Iu QoS Negotiation function is applied to the PS BE service,RNC select Iu max bit rate based on UE capacity,max bitrate and alternative RAB parameter values in RANAP RAB ASSIGNMENT REQUEST or RELOCATION REQUEST message,not consider cell capacity,this can avoid Iu QoS Renegotiation between different cell.The switch is valid when PS_BE_IU_QOS_NEG_SWITCH is set to ON. GUI Value Range: PS_BE_EXTRA_LOW_RATE_ACCESS_SWITCH, PS_BE_INIT_RATE_DYNAMIC_CFG_SWITCH, PS_BE_IU_QOS_NEG_SWITCH, PS_RAB_DOWNSIZING_SWITCH, PS_STREAM_IU_QOS_NEG_SWITCH, PS_BE_STRICT_IU_QOS_NEG_SWITCH Actual Value Range: PS_BE_EXTRA_LOW_RATE_ACCESS_SWITCH, PS_BE_INIT_RATE_DYNAMIC_CFG_SWITCH, PS_BE_IU_QOS_NEG_SWITCH, PS_RAB_DOWNSIZING_SWITCH, PS_STREAM_IU_QOS_NEG_SWITCH, PS_BE_STRICT_IU_QOS_NEG_SWITCH Unit: None

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Default Value: None

PucAvgFilterLen

BSC6900

SET ULDM(Optional)

Meaning: Length of smoothing filter window of potential user control (PUC). GUI Value Range: 1~32 Actual Value Range: 1~32 Unit: None Default Value: 6

QueueAlgoSwitch

BSC6900


Meaning: Indicating whether queue is supported. When a user initiates a call, if cell resources are insufficient and the user is queue supportive, the RNC tries to arrange this user to join the queue to increase access success ratio. GUI Value Range: OFF, ON Actual Value Range: OFF, ON Unit: None Default Value: OFF

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QueueLen BSC6900


Meaning: Queue length. The total number of users in queue of each cell should not exceed the value specified in this parameter. When a new user needs queuing, 1) If the queue has vacancy, the user joins the queue immediately. 2) If the queue is full and there is a user whose queue time exceeds the allowed maximum queue time, this user is out of the queue and access fails. At the same time, the new user joins the queue. 3) If the queue has a user whose priority is lower than that of the new user, the user in the queue with the lowest priority is out of the queue and access fails. At the same time, the new user joins the queue. 4)For other situations, the user cannot join the queue. GUI Value Range: 5~20 Actual Value Range: 5~20 Unit: None Default Value: 5

RateRecoverTimerLen

BSC6900


Meaning: DL fast TF restriction refers to a situation where, when the cell is overloaded and congested, the downlink TF can be adjusted to restrict the number of blocks transported in each TTI at the MAC layer and the rate of user data, thus reducing the cell downlink load. This parameter defines the downlink data rate recover timer length in fast TF restriction. RateRstrctTimerLen and RateRecoverTimerLen are effective only to the downlink. The uplink fast TF restriction is performed by the UE. For the uplink fast TF restriction, the RNC only delivers a new TFCS and randomly selects a comparatively bigger time length in the signaling value scope. The UE automatically release the TF restriction once the time expires. The higher RateRecoverTimerLen is, the more slowly the BE service rate recovers, while the lower probability that the overload is triggered again in a short period. The lower RateRecoverTimerLen is, the more quickly the BE service rate is recovered, but more overloads occur. GUI Value Range: 1~65535 Actual Value Range: 1~65535 Unit: ms Default Value: 5000

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RateRstrctCoef

BSC6900


Meaning: DL fast TF restriction refers to a situation where, when the cell is overloaded and congested, the downlink TF can be adjusted to restrict the number of blocks transported in each TTI at the MAC layer and the rate of user data, thus reducing the cell downlink load. This parameter defines the downlink data rate restrict coefficient in fast TF restrict The smaller this parameter is, the larger the TF restrict effect. The lower the parameter is, the more severe the rate is restricted. An excessive low parameter value, however, may affect the BE transmission delay. A high parameter value means loose restriction, which may be ineffective in alleviating the overload. GUI Value Range: 1~99 Actual Value Range: 0.01~0.99, step:0.01 Unit: % Default Value: 68

RateRstrctTimerLen

BSC6900


Meaning: DL fast TF restriction refers to a situation where, when the cell is overloaded and congested, the downlink TF can be adjusted to restrict the number of blocks transported in each TTI at the MAC layer and the rate of user data, thus reducing the cell downlink load. This parameter defines the time length of the downlink OLC fast TF restriction. RateRstrctTimerLen and RateRecoverTimerLen are effective only to the downlink. The uplink fast TF restriction is performed by the UE. For the uplink fast TF restriction, the RNC only delivers a new TFCS and randomly selects a comparatively bigger time length in the signaling value scope. The UE automatically release the TF restriction once the time expires. The higher RateRstrctTimerLen is, the more slowly the BE service rate decreases. The lower RateRstrctTimerLen is, the harder it is to receive the overload release instruction. GUI Value Range: 1~65535 Actual Value Range: 1~65535 Unit: ms Default Value: 3000

RecoverCoef BSC6900


Meaning: DL fast TF restriction refers to a situation where, when the cell is overloaded and congested, the downlink TF can be adjusted to restrict the number of blocks transported in each TTI at the MAC layer and the rate of user data, thus reducing the cell downlink load. This parameter defines the downlink OLC fast TF rate recovery coefficient. The greater this parameter is, the larger the TF restrict effect. GUI Value Range: 100~200 Actual Value Range: 1~2, step:0.01 Unit: % Default Value: 130

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RedirBandInd

BSC6900

ADD UCELLREDIRECTION(Optional) MOD UCELLREDIRECTION(Optional)

Meaning: Frequency band of the target UL and DL UARFCNs to which the UE is redirected. It is recommended that this parameter is set to Depending on the configuration of neighboring cells without the consideration of NRNC neighboring cells, that is, in the non-overlapped network. This helps avoid auto-redirection. Auto-redirection is a case in which redirection is initiated in the current cell when the UARFCN to which the UE is redirected is the same as that of the current cell. GUI Value Range: Band1, Band2, Band3, Band4, Band5, Band6, Band7, Band8, Band9, DependOnNCell, BandIndNotUsed Actual Value Range: BAND1, BAND2, BAND3, BAND4, BAND5, BAND6, BAND7, BAND8, BAND9, DependOnNCell, BANDINDNOTUSED Unit: None Default Value: None

ReDirUARFCNDownlink

BSC6900

ADD UCELLDRD(Optional) MOD UCELLDRD(Optional)

Meaning: Target DL UARFCN for the RRC redirection. Different values of "RedirBandInd" correspond to different value ranges of the UARFCN. GUI Value Range: 0~16383 Actual Value Range: 0~16383 Unit: None Default Value: None

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ReDirUARFCNUplink

BSC6900


Meaning: Target uplink UARFCN of a cell for RRC redirection. The value range of the UL UARFCN depends on the value of "RedirBandInd". The relation between "RedirBandInd" and the value range of the UL UARFCN is as follows: BAND1 Common UARFCNs: [9612-9888] Special UARFCNs: none BAND2 Common UARFCNs: [9262-9538] Special UARFCNs: {12, 37, 62, 87, 112, 137, 162, 187, 212, 237, 262, 287} BAND3 Common UARFCNs: [937-1288] Special UARFCNs: none BAND4 Common UARFCNs: [1312-1513] Special UARFCNs: {1662, 1687, 1712, 1737, 1762, 1787, 1812, 1837, 1862} BAND5 Common UARFCNs: [4132-4233] Special UARFCNs: {782, 787, 807, 812, 837, 862} BAND6 Common UARFCNs: [4162-4188] Special UARFCNs: {812, 837} BAND7 Common UARFCNs: [2012-2338] Special UARFCNs: {2362, 2387, 2412, 2437, 2462, 2487, 2512, 2537, 2562, 2587, 2612, 2637, 2662, 2687} BAND8 Common UARFCNs: [2712-2863] Special UARFCNs: none BAND9 Common UARFCNs: [8762-8912] Special UARFCNs: none BandIndNotUsed: [0-16383] If the UL UARFCN is not manually configured, if RedirBandInd is set to BAND1, BAND2, BAND3, BAND4, BAND5, BAND6, BAND7, BAND8, or BAND9, and if the DL UARFCN is valid, then the target UL UARFCN of the redirection is automatically configured according to the following principles: If the DL UARFCN is a common UARFCN, the relation between the UL UARFCN and the DL UARFCN is as follows: BAND1: UL UARFCN = DL UARFCN - 950 BAND2: UL UARFCN = DL UARFCN - 400 BAND3: UL UARFCN = DL UARFCN - 225 BAND4: UL UARFCN = DL UARFCN - 225 BAND5: UL UARFCN = DL UARFCN - 225 BAND6: UL UARFCN = DL UARFCN - 225 BAND7: UL UARFCN = DL UARFCN - 225 BAND8: UL UARFCN = DL UARFCN - 225 BAND9: UL UARFCN = DL UARFCN - 475 If the DL UARFCN is a special UARFCN, the relation between the UL UARFCN and the DL UARFCN is as follows:

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BAND2: UL UARFCN = DL UARFCN - 400 BAND4: UL UARFCN = DL UARFCN - 225 BAND5: UL UARFCN = DL UARFCN - 225 BAND6: UL UARFCN = DL UARFCN - 225 BAND7: UL UARFCN = DL UARFCN - 225 GUI Value Range: 0~16383 Actual Value Range: 0~16383 Unit: None Default Value: None

ReDirUARFCNUplinkInd

BSC6900


Meaning: Whether the target UL UARFCN to which the UE is redirected needs to be configured. TRUE indicates that the UL UARFCN needs to be configured. FALSE indicates that the UL UARFCN need not be manually configured and it is automatically configured according to the relation between the UL and DL UARFCNs. GUI Value Range: TRUE, FALSE Actual Value Range: TRUE, FALSE Unit: None Default Value: None

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ReDirUARFCNUplinkInd

BSC6900


Meaning: Whether the target UL UARFCN to which the UE is redirected needs to be configured. TRUE indicates that the UL UARFCN needs to be configured. FALSE indicates that the UL UARFCN need not be manually configured and it is automatically configured according to the relation between the UL and DL UARFCNs. GUI Value Range: FALSE, TRUE Actual Value Range: FALSE, TRUE Unit: None Default Value: None

RedirFactorOfLDR

BSC6900

ADD UCELLDISTANCEREDIRECTION(Optional) MOD UCELLDISTANCEREDIRECTION(Optional)

Meaning: When the UL load state or DL load state of the serving cell is LDR(basic congestion) or OLC(overload congestion), a UE may be redirected to another cell according to the distance between UE and current cell. This parameter specifies the possibility of redirecting the UE to another cell. When this parameter is set to 0, the distance based RRC redirection is not performed if the load state on the serving cell is LDR or OLC. GUI Value Range: 0~100 Actual Value Range: 0~100 Unit: % Default Value: 50

RedirFactorOfNorm

BSC6900

ADD UCELLDISTANCEREDIRECTION(Optional) MOD UCELLDISTANCEREDIRECTION(Optional)

Meaning: When the load of the serving cell is within the normal range, a UE may be redirected to another cell according to the distance between UE and current cell. This parameter specifies the possibility of redirecting the UE to another cell. When this parameter is set to 0, the RRC redirection is not performed if the load of the serving cell is within the normal range. GUI Value Range: 0~100 Actual Value Range: 0~100 Unit: % Default Value: 0

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RedirSwitch BSC6900


Meaning: Whether the RRC redirection algorithm is valid for the specified service. The algorithm is valid only when the RRC direct redirection switch is enabled and when this parameter is set to ONLY_TO_INTER_FREQUENCY or ONLY_TO_INTER_RAT. - OFF indicates that RRC redirection is not allowed. - Only_To_Inter_Frequency indicates that only RRC redirection to inter-frequency cells is allowed. - Only_To_Inter_Frequency indicates that only RRC redirection to inter-RAT cells is allowed. GUI Value Range: OFF, ONLY_TO_INTER_FREQUENCY, ONLY_TO_INTER_RAT Actual Value Range: OFF, ONLY_TO_INTER_FREQUENCY, ONLY_TO_INTER_RAT Unit: None Default Value: None

SeqOfUserRel

BSC6900

ADD UCELLOLC(Optional)

Meaning: This parameter indicates whether the MBMS service is released first or user first when the overload occurs. GUI Value Range: MBMS_REL(MBMS service), USER_REL(UE) Actual Value Range: MBMS_REL, USER_REL Unit: None Default Value: MBMS_REL

SpucHeavy BSC6900


Meaning: It is used to decide whether the cell load level is "Heavy" or not. It is denoted by the ratio of NodeB TX power to the maximum TX power. If the load of a cell is equal to or higher than this threshold, the load level of this cell is heavy. If the load level of a cell is heavy, the PUC algorithm will configure selection/reselection parameters for this cell to lead the UE camping on this cell to reselect another inter-frequency neighboring cell with light load. GUI Value Range: 0~100 Actual Value Range: 0~1, step:0.01 Unit: % Default Value: 70

SpucHyst BSC6900


Meaning: Hysteresis used to determine the cell load level. It is denoted by the ratio of NodeB TX power to the maximum TX power. It is used to avoid the unnecessary ping-pong effect of a cell between two load levels due to tiny load change. For detailed information of this parameter, refer to 3GPP TS 25.304. GUI Value Range: 0~100 Actual Value Range: 0~1, step:0.01 Unit: %

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Default Value: 5

SpucLight BSC6900


Meaning: It is used to decide whether the cell load level is "Light" or not. It is denoted by the ratio of NodeB TX power to the maximum TX power. If the load of a cell is equal to or lower than this threshold, the load level of this cell is light. If the load level of a cell is light, the PUC algorithm will configure selection/reselection parameters for this cell to lead the UE to reselect this cell rather than the previous inter-frequency neighboring cell with heavy load. GUI Value Range: 0~100 Actual Value Range: 0~1, step:0.01 Unit: % Default Value: 45

TargetFreqThdEcN0

BSC6900

ADD UCELLMCDRD(Optional) MOD UCELLMCDRD(Optional)

Meaning: Ec/No Threshold for the target cell. This parameter is used to estimate the signal quality of the periodic reports. The DRD is triggered only when the signal quality of the target cell is higher than this parameter. If this parameter is set to a greater value, it is difficult for subscribers to re-access another cell with a higher priority; however, the re-attempt success rate is high. If this parameter is set to a lower value, it is easy for subscribers to re-access another cell with a higher priority; however, the re-attempt success rate however is low. Note: The threshold can be reached only when RSCP and Ec/No of the target cell are above the RSCP and EcNo that are set in the command.In order to increase the successful rate of handover, inner protection mechanism keep Ec/No of target cell larger than -16. GUI Value Range: -24~0 Actual Value Range: -24~0 Unit: dB Default Value: -12

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TargetFreqThdRscp

BSC6900

ADD UCELLMCDRD(Optional) MOD UCELLMCDRD(Optional)

Meaning: RSCP Threshold for the target cell. This parameter is used to estimate the signal quality of the periodic reports.The DRD is triggered only when the signal quality of the target cell is higher than this parameter. If this parameter is set to a greater value, it is difficult for subscribers to re-access another cell with a higher priority; however, the re-attempt success rate is high. If this parameter is set to a lower value, it is easy for subscribers to re-access another cell with a higher priority; however, the re-attempt success rate however is low. Note: The threshold can be reached only when RSCP and Ec/No of the target cell are above the RSCP and Ec/No that are set in the command. GUI Value Range: -115~-25 Actual Value Range: -115~-25 Unit: dBm Default Value: -92

TenMsecForDlBasicMeas

BSC6900

SET ULDM(Mandatory)

Meaning: DL basic common measurement report cycle. For detailed information of this parameter, refer to 3GPP TS 25.433. GUI Value Range: 1~6000 Actual Value Range: 10~60000, step:10 Unit: ms Default Value: 100

TenMsecForHsdpaPrvidRateMeas

BSC6900

SET ULDM(Mandatory)

Meaning: This parameter specifies the HSDPA bit rate measurement report period. For detailed information of this parameter, refer to 3GPP TS 25.433. GUI Value Range: 1~6000 Actual Value Range: 10~60000, step:10 Unit: ms Default Value: 100

TenMsecForHsdpaPwrMeas

BSC6900

SET ULDM(Mandatory)

Meaning: HSDPA power requirement measurement report period For detailed information of this parameter, refer to 3GPP TS 25.433. GUI Value Range: 1~6000 Actual Value Range: 10~60000, step:10 Unit: ms Default Value: 100

TenMsecForHsupaPrvidRateMeas

BSC6900

SET ULDM(Mandatory)

Meaning: This parameter specifies the HSUPA bit rate measurement report period. For detailed information of this parameter, refer to 3GPP TS 25.433. GUI Value Range: 1~6000 Actual Value Range: 10~60000, step:10 Unit: ms Default Value: 100

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TenMsecForUlBasicMeas

BSC6900

SET ULDM(Mandatory)

Meaning: UL basic common measurement report cycle. For detailed information of this parameter, refer to 3GPP TS 25.433. GUI Value Range: 1~6000 Actual Value Range: 10~60000, step:10 Unit: ms Default Value: 100

TransCchUserNum

BSC6900


Meaning: Transfer Common Channel User number Value range: 0~10 Content: When the system is overloaded and congested, users on the DCH can be reconfigured to the CCH in order to reduce the cell load and recover the system. The mechanism of the OLC is that an action is performed in each [OLC period] and some services are selected based on the action rules to perform this action. This parameter defines the maximum number of users selected in executing reconfiguration to the CCH. If the parameter value is too high, the OLC action may fluctuate greatly and over control may occur (the state of overload and congestion turns into another extreme--under load). If the parameter value is too low, the OLC action has a slow response and the effect is not apparent, affecting the OLC performance. GUI Value Range: 0~10 Actual Value Range: 0~10 Unit: None Default Value: 1

UlBasicCommMeasFilterCoeff

BSC6900

SET ULDM(Optional)


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UlBeTraffInitBitrate

BSC6900

SET UFRC(Optional)

Meaning: UL initial access rate of PS background or interactive service. When DCCC function is enabled, the uplink initial access rate will be set to this value if the uplink maximum rate is higher than the initial access rate. A higher value indicates that it takes shorter time for BE services to reach the maximum rate. Note that the rate will be decreased through negotiation when congestion occurs. A smaller value indicates that BE services is easier to be accessed. It is not recommended to set a too small value, because it will take longer time for BE services to adjust to a higher rate when needed. GUI Value Range: D8, D16, D32, D64, D128, D144, D256, D384 Actual Value Range: 8, 16, 32, 64, 128, 144, 256, 384 Unit: kbit/s Default Value: D64

UlCacAvgFilterLen

BSC6900

SET ULDM(Optional)

Meaning: Length of smoothing filter window of uplink CAC. GUI Value Range: 1~32 Actual Value Range: 1~32 Unit: None Default Value: 5

UlCSInterRatShouldBeHOUeNum

BSC6900


Meaning: Number of users selected in a UL LDR CS domain inter-RAT SHOULDBE load handover. The target subscribers of this parameter are the CS domain subscribers. Because the CS domain subscribers are session subscribers in general and they have little impact on load, you can set this parameter to a comparatively high value. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None Default Value: 3

UlCSInterRatShouldNotHOUeNum

BSC6900


Meaning: Number of users selected in a UL LDR CS domain inter-RAT SHOULDNOTBE load handover. The target subscribers of this parameter are the CS domain subscribers. Because the CS domain subscribers are session subscribers in general and they have little impact on load, you can set this parameter to a comparatively high value. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None Default Value: 3

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UlDcccRateThd

BSC6900

SET UDCCC(Optional)

Meaning: For a BE service that has a low maximum rate, the DCCC algorithm is not obviously effective yet it increases algorithm processing. Thus, the traffic-based DCCC algorithm is applied to BE services whose maximum UL rate is greater than the threshold. GUI Value Range: D8, D16, D32, D64, D128, D144, D256, D384 Actual Value Range: 8, 16, 32, 64, 128, 144, 256, 384 Unit: kbit/s Default Value: D64

UlInterFreqHoBWThd

BSC6900


Meaning: The UE can be selected to process load handover only when its bandwidth is less than this threshold. GUI Value Range: 0~400000 Actual Value Range: 0~400000 Unit: bit/s Default Value: 200000

UlInterFreqHoCellLoadSpaceThd

BSC6900


Meaning: The inter-frequency neighboring cell could be selected as the destination of load handover only when its load remaining space is larger than this threshold. The lower the parameter is, the easier it is to find a qualified target cell for the blind handover. Excessively small value of the parameter, however makes the target cell easily enter the congestion status. The higher the parameter is, the more difficult it is for the inter-frequency blind handover occurs. GUI Value Range: 0~100 Actual Value Range: 0~1, step:0.01 Unit: % Default Value: 20

UlLdrAMRRateReductionRabNum

BSC6900


Meaning: The mechanism of the LDR is that an action is performed in each [LDR period] and some services are selected based on the action rules to perform this action. This parameter defines the maximum number of RABs selected in executing uplink LDR-AMR voice service rate reduction. If the parameter value is too high, the LDR action may fluctuate greatly and over control may occur (the state of basic congestion turns into another extreme--under load). If the parameter value is too low, the LDR action has a slow response and the effect is not apparent, affecting the LDR performance. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None Default Value: 1

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UlLdrAvgFilterLen

BSC6900

SET ULDM(Optional)

Meaning: Length of smoothing filter window of uplink LDR. GUI Value Range: 1~32 Actual Value Range: 1~32 Unit: None Default Value: 5

UlLdrBERateReductionRabNum

BSC6900


Meaning: Number of RABs selected in a UL LDR BE traffic rate reduction. In the actual system, this parameter can be set on the basis of the actual circumstances. If the high-rate subscribers occupy a high proportion, set the parameter to a comparatively low value. If the high-rate subscribers occupy a low proportion, set the parameter to a comparatively high value. Because the basic congestion control algorithm is designed to slowly decrease cell load, you need to set this parameter to a comparatively low value. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None Default Value: 1

UlLdrCreditSfResThd

BSC6900


Meaning: Reserved SF threshold in uplink credit LDR. The uplink credit LDR could be triggered only when the SF factor corresponding to the uplink reserved credit is higher than the uplink or downlink credit SF reserved threshold. GUI Value Range: SF4(SF4), SF8(SF8), SF16(SF16), SF32(SF32), SF64(SF64), SF128(SF128), SF256(SF256) Actual Value Range: SF4, SF8, SF16, SF32, SF64, SF128, SF256 Unit: None Default Value: SF8

UlLdrPsRTQosRenegRabNum

BSC6900


Meaning: Number of RABs selected in a UL LDR uncontrolled real-time traffic QoS renegotiation. The target subscribers of this parameter are the PS domain real-time subscribers. The setting of this parameter is analogous to the setting of BE service rate reduction subscriber number. Because the number of subscribers performing QoS renegotiation may be smaller than the value of this parameter, for example, the candidate subscribers selected for downlink LDR do not meet the QoS renegotiation conditions, you must leave some margin when setting this parameter to ensure the success of load reshuffling. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None Default Value: 1

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UlLdrRelThd BSC6900


Meaning: If the ratio of UL load of the cell to the uplink capacity is lower than this threshold, the UL load reshuffling function of the cell is stopped. After the basic congestion state of the cell load is released, the system no longer implements the LDR action. Because the load fluctuates, the difference between the LDR release threshold and trigger threshold should be higher than 10%. The ping-pong effect of the preliminary congestion state may occur. GUI Value Range: 0~100 Actual Value Range: 0~1, step:0.01 Unit: % Default Value: 45

UlLdrTrigThd BSC6900


Meaning: If the ratio of UL load of the cell to the uplink capacity is not lower than this threshold, the UL load reshuffling function of the cell is triggered. After the basic congestion state of the cell load is released, the system no longer implements the LDR action. Because the load fluctuates, the difference between the LDR release threshold and trigger threshold should be higher than 10%. The ping-pong effect of the preliminary congestion state may occur. GUI Value Range: 0~100 Actual Value Range: 0~1, step:0.01 Unit: % Default Value: 55

UlOlcAvgFilterLen

BSC6900

SET ULDM(Optional)

Meaning: Length of smoothing filter window of uplink OLC. GUI Value Range: 1~32 Actual Value Range: 1~32 Unit: None Default Value: 5

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9-55


UlOlcFTFRstrctRabNum

BSC6900


Meaning: UL fast TF restriction refers to a situation where, when the cell is overloaded and congested, the uplink TF can be adjusted to restrict the number of blocks transported in each TTI at the MAC layer and the rate of user data, thus reducing the cell uplink load. The mechanism of the OLC is that an action is performed in each [OLC period] and some services are selected based on the action rules to perform this action. This parameter defines the maximum number of RABs selected in executing uplink OLC fast restriction. Selection of RABs of the OLC is based on the service priorities and ARP values and bearing priority indication. The RAB of low priority is under control. In the actual system, UlOlcFTFRstrctRabNum and DlOlcFTFRstrctRabNum can be set on the basis of the actual circumstances. If the high-rate subscribers occupy a high proportion, set UlOlcFTFRstrctRabNum and DlOlcFTFRstrctRabNum to comparatively low values. If the high-rate subscribers occupy a low proportion, set UlOlcFTFRstrctRabNum and DlOlcFTFRstrctRabNum to comparatively high values. The higher the parameters are, the more users are involved in fast TF restriction under the same conditions, the quicker the cell load decreases, and the more user QoS is affected. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None Default Value: 3

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9-56


UlOlcFTFRstrctTimes

BSC6900


Meaning: UL fast TF restriction refers to a situation where, when the cell is overloaded and congested, the uplink TF can be adjusted to restrict the number of blocks transported in each TTI at the MAC layer and the rate of user data, thus reducing the cell uplink load. The mechanism of the OLC is that an action is performed in each [OLC period] and some services are selected based on the action rules to perform this action. This parameter defines the maximum number of uplink OLC fast TF restriction performed in entering/exiting the OLC status. After the overload is triggered, the RNC immediately executes OLC by first executing fast TF restriction. The internal counter is incremented by 1 with each execution. If the number of overloads does not exceed the OLC action threshold, the system lowers the BE service rate by lowering TF to relieve the overload. If the number of overloads exceeds the OLC action threshold, the previous operation has no obvious effect on alleviating the overload and the system has to release users to solve the overload problem. The lower the parameters are, the more likely the users are released, resulting in negative effect on the system performance. If the parameters are excessively high, the overload status is released slowly. GUI Value Range: 0~100 Actual Value Range: 0~100 Unit: None Default Value: 3

UlOlcMeasFilterCoeff

BSC6900

SET ULDM(Optional)


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9-57


UlOlcRelThd BSC6900


Meaning: If the ratio of UL load of the cell to the uplink capacity is lower than this threshold, the UL overload and congestion control function of the cell is stopped. The value of the OLC release threshold should not be much lower than or close to the OLC trigger threshold, or the system state may have a ping-pong effect. The recommended difference between the OLC release threshold and the OLC trigger threshold is higher than 10%. It is desirable to set the two parameters a bit higher given that the difference between OLC trigger threshold and OLC release threshold is fixed. GUI Value Range: 0~100 Actual Value Range: 0~1, step:0.01 Unit: % Default Value: 85

UlOlcTraffRelRabNum

BSC6900


Meaning: User release is an extreme method in reducing the cell load and recovering the system when the cell is overloaded and congested. The mechanism of the OLC is that an action is performed in each [OLC period] and some services are selected based on the action rules to perform this action. This parameter defines the maximum number of RABs released in executing uplink OLC service release. For the users of a single service, the releasing of RABs means the complete releasing of the users. The releasing of RABs causes call drops, so UlOlcFTFRstrctTimes or DlOlcFTFRstrctTimes should be set to a low value. Higher values of the parameter get the cell load to decrease more obviously, but the QoS will be affected. GUI Value Range: 0~10 Actual Value Range: 0~10 Unit: None Default Value: 0

UlOlcTrigHyst

BSC6900

SET ULDM(Optional)

Meaning: UL OLC trigger hysteresis.This parameter can avoid touching off OLC event continually. GUI Value Range: 1~6000 Actual Value Range: 10~60000, step:10 Unit: None Default Value: 100

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UlOlcTrigThd BSC6900


Meaning: If the ratio of UL load of the cell to the uplink capacity is not lower than this threshold, the UL overload and congestion control function of the cell is triggered. The value of the OLC release threshold should not be much lower than or close to the OLC trigger threshold, or the system state may have a ping-pong effect. The recommended difference between the OLC release threshold and the OLC trigger threshold is higher than 10%. It is desirable to set the two parameters a bit higher given that the difference between OLC trigger threshold and OLC release threshold is fixed. GUI Value Range: 0~100 Actual Value Range: 0~1, step:0.01 Unit: % Default Value: 95

UlPSInterRatShouldBeHOUeNum

BSC6900


Meaning: Number of users selected in a UL LDR PS domain inter-RAT SHOULDBE load handover. The target subscribers of this parameter are the PS domain subscribers. In the actual system, this parameter can be set on the basis of the actual circumstances. If the high-rate subscribers occupy a high proportion, set the parameter to a comparatively low value. If the high-rate subscribers occupy a low proportion, set the parameter to a comparatively high value. Because the basic congestion control algorithm is designed to slowly decrease cell load, you need to set this parameter to a comparatively low value. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None Default Value: 1

UlPSInterRatShouldNotHOUeNum

BSC6900


Meaning: Number of users selected in a UL LDR PS domain inter-RAT SHOULDNOTBE load handover. The target subscribers of this parameter are the PS domain subscribers. In the actual system, this parameter can be set on the basis of the actual circumstances. If the high-rate subscribers occupy a high proportion, set the parameter to a comparatively low value. If the high-rate subscribers occupy a low proportion, set the parameter to a comparatively high value. Because the basic congestion control algorithm is designed to slowly decrease cell load, you need to set this parameter to a comparatively low value. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None Default Value: 1

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ZeroRateUpFailToRelTimerLen

BSC6900

SET UCOIFTIMER(Optional)

Meaning: For the PS BE service at a rate of 0 kbit/s, this parameter is used for the rate upsizing for DCCC triggered by event 4A. Unsuccessful rate upsizing indicates that the resources are insufficient in the cell. The service may run at a rate of 0 kbit/s for a long time. If the timer is started, the 0 kbit/s service of the UE is released after the timer expires. If the length is set to 0, the timer is not started. GUI Value Range: 0~65535 Actual Value Range: 0~65535 Unit: s Default Value: 180

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Load Control 10 Counters



10-1

10 Counters

For details, see the BSC6900 UMTS Performance Counter Reference and the NodeB Performance Counter Reference.

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Load Control 11 Glossary



11-1

11 Glossary

For the acronyms, abbreviations, terms, and definitions, see the Glossary.

Glossary.htm

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Load Control 12 Reference Documents



12-1

12 Reference Documents

[1] 3GPP TS 25.133: Requirements for Support of Radio Resource Management (FDD)

[2] 3GPP TS 25.215: Physical layer - Measurements (FDD)

[3] 3GPP TS 25.321: Medium Access Control (MAC) protocol specification

[4] 3GPP TS 25.331: Radio Resource Control (RRC)

[5] 3GPP TS 25.413: UTRAN Iu Interface RANAP Signaling

[6] AMR Feature Parameter Description

[7] DCCC Feature Parameter Description

[8] State Transition Feature Parameter Description

[9] MBMS Feature Parameter Description

[10] HSDPA Feature Parameter Description

[11] HSUPA Feature Parameter Description

[12] Transmission Resource Management Feature Parameter Description

[13] Handover Feature Parameter Description

AMR.htm

DCCC.htm

State%20Transition.htm

MBMS.htm

HSDPA.htm

HSUPA.htm


Handover.htm

load control

Documents

pwr meas cycle

hspa technological satisfaction

mml command description

quick tf restriction

l3 filtering coefficient

fast tf restriction

smoothing filter window

initial rate definition