call admission control(ran13.0_02)

Call Admission Control RAN13.0

Feature Parameter Description

Issue 02

Date 2011-12-30

HUAWEI TECHNOLOGIES CO., LTD.

Copyright Huawei Technologies Co., Ltd. 2012. All rights reserved.

No part of this document may be reproduced or transmitted in any form or by any means without prior

written consent of Huawei Technologies Co., Ltd.

Trademarks and Permissions

and other Huawei trademarks are trademarks of Huawei Technologies Co., Ltd.

All other trademarks and trade names mentioned in this document are the property of their respective

holders.

Notice

The purchased products, services and features are stipulated by the contract made between Huawei and

the customer. All or part of the products, services and features described in this document may not be

within the purchase scope or the usage scope. Unless otherwise specified in the contract, all statements,

information, and recommendations in this document are provided "AS IS" without warranties, guarantees or

representations of any kind, either express or implied.

The information in this document is subject to change without notice. Every effort has been made in the

preparation of this document to ensure accuracy of the contents, but all statements, information, and

recommendations in this document do not constitute the warranty of any kind, express or implied.

Huawei Technologies Co., Ltd.

Address: Huawei Industrial Base

Bantian, Longgang

Shenzhen 518129

People's Republic of China

Website: http://www.huawei.com

Email: [email protected]

WCDMA RAN

Call Admission Control Contents

Issue 02 (2011-12-30) Huawei Proprietary and Confidential

Copyright Huawei Technologies Co., Ltd

i

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 Call Admission Control ................................................................................... 2-1

3 Technical Description .............................................................................................................. 3-1

3.1 Overview ....................................................................................................................................... 3-1

3.1.1 Admission Resource and Basic Procedure .......................................................................... 3-1

3.1.2 HSDPA Admission Control .................................................................................................... 3-2

3.1.3 HSUPA Admission Control .................................................................................................... 3-2

3.2 CAC Based on Code Resources ................................................................................................... 3-3

3.3 CAC Based on Power Resources ................................................................................................. 3-4

3.3.1 Overview ............................................................................................................................... 3-4

3.3.2 Power-based Admission Control on RRC Connection Setup Requests .............................. 3-5

3.3.3 Power-based Admission Algorithm 1 for RAB Setup ............................................................ 3-7

3.3.4 Power-based Admission Algorithm 2 for RAB Setup .......................................................... 3-14

3.3.5 Power-based Admission Algorithm 3 for RAB Setup .......................................................... 3-17

3.4 CAC Based on NodeB Credit Resources ................................................................................... 3-18

3.4.1 NodeB Credit Resources .................................................................................................... 3-18

3.4.2 NodeB Credit Resource-based Admission Decisions ........................................................ 3-18

3.5 CAC Based on Iub Resources .................................................................................................... 3-19

3.6 CAC Based on the Number of HSPA Users ................................................................................ 3-20

3.6.1 CAC for HSDPA Users ....................................................................................................... 3-20

3.6.2 CAC for HSUPA Users ....................................................................................................... 3-20

4 Parameters.................................................................................................................................. 4-1

5 Counters ...................................................................................................................................... 5-1

6 Glossary ...................................................................................................................................... 6-1

7 Reference Documents ............................................................................................................. 7-1

WCDMA RAN

Call Admission Control 1 Introduction



1-1

1 Introduction

1.1 Scope

This document describes the call admission control feature WRFD-020101 Admission Control. It describes how services are granted the network access and provides the parameters associated with this feature.

1.2 Intended Audience

This document is intended for:

Personnel who are familiar with WCDMA basics

Personnel who need to understand Call Admission Control (CAC)

Personnel who work with Huawei products

1.3 Change History

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

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

Feature change: refers to a change in the CAC feature of a specific product version.

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

Document Issues

The document issues are as follows:

02 (2011-12-30)

01 (2011-04-30)

Draft B (2011-03-30)

Draft A (2010-12-30)

02 (2011-12-30)

This is the document for the second commercial release of RAN13.0.

Compared with 01 (2011-04-30) of RAN13.0, this issue incorporates the following changes:

Change Type Change Description Parameter Change

Feature change The admission for RRC connections is optimized. For detailed information, see the following section:

3.2 CAC Based on Code Resources

3.3.2 Power-based Admission Control on RRC Connection Setup Requests

3.4.2 NodeB Credit Resource-based Admission Decisions

None.

WCDMA RAN

Call Admission Control 1 Introduction



1-2

Change Type Change Description Parameter Change

The admission for AMR services is optimized to increase the access success rate of AMR services. For detailed information, search the phrase to increase the access success rate of AMR services.

None.

Editorial change The detailed information about call admission control is provided.

None.

01 (2011-04-30)

This is the document for the first commercial release of RAN13.0.

Compared with Draft B (2011-03-30) of RAN13.0, this issue has no change.

Draft B (2011-03-30)

This is the second draft of the document for RAN13.0.

Compared with Draft A (2010-12-30) of RAN13.0, this issue optimizes the description.

Draft A (2010-12-30)

This is the first draft of the document for RAN13.0.

Compared with issue 04 (2010-12-20) of RAN12.0, this issue optimizes the description.

WCDMA RAN

Call Admission Control 2 Overview of Call Admission Control



2-1

2 Overview of Call Admission Control

Call Admission Control (CAC) is used to determine whether the system resources in a cell are sufficient to accept a resource request. If the system resources are sufficient, the resource request is accepted; otherwise, the resource request is rejected.

A radio link sends a resource request to the CAC functional module when additional resources are required, in cases such as radio resource control (RRC) connection setup, new service setup, change of existing services, soft handover, and cell change. Upon receiving a resource request, the CAC functional module determines whether the request can be accepted by measuring the cell load and the requested resources. For details about measuring the cell load, see the Load Control Feature Parameter Description.

The admission decision performed using CAC is based on the following resources: code resources, power resources, NodeB credit resources, and Iub resources. In the case of an 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.

With CAC, an overloaded cell can accept resource requests for an RRC connection setup only in the case of emergency calls, detachments, or registrations. This is because the priority of such requests is very high. This helps maintain system stability when cells are overloaded. In addition, admitting or rejecting users over FACH or enhanced FACH channels (HS-DSCH) in an overloaded cell can be specified by setting FACH_UU_ADCTRL of the NBMCacAlgoSwitch parameter.

WCDMA RAN

Call Admission Control 3 Technical Description



3-1

3 Technical Description

3.1 Overview

3.1.1 Admission Resource and Basic Procedure

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 performs the admission decision based on the following resources:

Available cell code resources

Available cell power resources

NodeB credit resources, which are used to measure the channel demodulation capability of NodeBs

Available Iub transmission bandwidth

Number of HSDPA users (only for HSDPA services)

Number of HSUPA users (only for HSUPA services)

A call can be admitted only when all of these resources are available.

Code resource-based and Iub resource-based admission control are mandatory and cannot be disabled. For HSDPA/HSUPA services, admission control based on the number of HSUPA/HSDPA users is also mandatory. Other admission control policies are enabled or disabled by running the MOD UCELLALGOSWITCH or SET UCACALGOSWITCH command.

Figure 3-1 shows the basic procedure for a resource-based admission decision.

WCDMA RAN




3-2

Figure 3-1 Basic procedure for a resource-based admission decision

3.1.2 HSDPA Admission Control

HSDPA admission control (WRFD-01061003 HSDPA Admission Control) enables the HSDPA service along with other R99 services to access the network by using the remaining power resources and other resources. Admission control based on the number of HSDPA users is also considered.

Iub resource admission for HSDPA users is also performed during admission control to grant HSDPA services and other R99 services the access to resources to ensure a certain QoS.

HSDPA admission control is described in this document, along with R99 admission control.

3.1.3 HSUPA Admission Control

HSUPA admission control (WRFD-01061202 HSUPA Admission Control) enables HSUPA services along with other R99 services to access the network by using the remaining uplink cell load and other resources. Admission based on the number of HSUPA users is also considered.

Iub resource admission and NodeB credit resources for HSUPA users are also performed during admission control to grant HSUPA service and other R99 services the access to resources to ensure a certain QoS.

WCDMA RAN




3-3

HSUPA admission control is described in this document, along with R99 admission control.

3.2 CAC Based on Code Resources

Code resource-based admission is mandatory when a non-HSDPA service attempts to access the network.

The reserved code resources are shared by all HSDPA services and therefore code resource-based admission control for HSDPA services is not required. For details about code allocation for HSDPA services, see the HSDPA Feature Parameter Description.

In code resource-based admission, the admission criteria vary with the service request.

RRC Connection Setup Requests

For an RRC connection setup request, code resource-based admission is implemented as follows:

When RSVDBIT11 under the RsvdPara1 parameter in the ADD UCELLALGOSWITCH command is set to 0, code resource-based admission succeeds if the remaining code resources are sufficient for setting up an RRC connection.

When RSVDBIT11 under the RsvdPara1 parameter in the ADD UCELLALGOSWITCH command is set to 1, the RNC implements code resource-based admission based on the cause carried in the RRC connection setup request:

If the cause is "Emergency Call" or "Detach", code resource-based admission succeeds if the remaining code resources are sufficient.

For any other cause, the RNC must ensure that the remaining codes (the remaining minimum SF of the current cell) do not exceed the reserved minimum spreading factor (SF) for an RRC connection upon admitting an RRC connection setup request. The reserved minimum SF is specified by RSVDBIT12 under the RsvdPara1 parameter in the ADD UCELLALGOSWITCH command.

a. If RSVDBIT12 under the RsvdPara1 parameter is set to 0, the reserved minimum SF is SF128.

b. If RSVDBIT12 under the RsvdPara1 parameter is set to 1, the reserved minimum SF is SF32.

Handover Service Requests

For handover service requests, code resource-based admission succeeds if the remaining code resources are sufficient for the service to be admitted.

PS Service/CS Service (Non-AMR Service) Requests

For PS services/CS service (non-AMR service) requests, the RNC must ensure that the remaining codes (the remaining minimum SF of the current cell) upon admitting a new service do not exceed the threshold which is specified by the DlHoCeCodeResvSf parameter.

AMR Service Requests

For AMR service requests,

When RSVDBIT11 under the RsvdPara1 parameter in the ADD UCELLALGOSWITCH command is set to 0, the RNC must ensure that the remaining codes (the remaining minimum SF of the current cell) upon admitting a new service do not exceed the threshold specified by the DlHoCeCodeResvSf parameter.

When RSVDBIT11 under the RsvdPara1 parameter in the ADD UCELLALGOSWITCH command is set to 1, code resource-based admission succeeds if the remaining code resources are sufficient for the service to be admitted.

WCDMA RAN




3-4

3.3 CAC Based on Power Resources

3.3.1 Overview

Power-based admission is used for RRC connection setup requests and radio access bearer (RAB) admission. The power-based admission algorithm is enabled or disabled by the NBMUlCacAlgoSelSwitch/NBMDlCacAlgoSelSwitch parameter.

To enable power-based admission control for HSDPA or HSUPA services, select HSDPA_UU_ADCTRL or HSUPA_UU_ADCTRL under the NBMCacAlgoSwitch parameter.

CAC based on power resources is performed by using one of the following three algorithms:

Algorithm 1 (ALGORITHM_FIRST): admission control based on the expected load increase caused by a new service

Depending on the current cell power load, the RNC determines whether the cell load will exceed the threshold upon admitting the new service. If the cell load exceeds the threshold, the RNC rejects the access request. Otherwise, the RNC admits the service.

Algorithm 2 (ALGORITHM_SECOND): admission control based on the equivalent number of users (ENU)

Depending on the current ENU load and the access request, the RNC determines whether the ENU will exceed the threshold upon admitting the new request. If the ENU exceeds the threshold, the RNC rejects the access request. Otherwise, the RNC admits the service.

Algorithm 3 (ALGORITHM_THIRD): admission control without considering load increase caused by a new service

This algorithm assumes that the load increase caused by the new service is 0. Based on the current cell power load, the RNC determines whether the cell load will exceed the threshold. If the cell load exceeds the threshold, the RNC rejects the access request. Otherwise, the RNC admits the service.

Figure 3-2 shows the basic procedure for a power-based admission decision.

WCDMA RAN




3-5

Figure 3-2 Basic procedure for a power-based admission decision

The basic principles for a power-based admission decision are as follows:

For an intra-frequency handover request, only a downlink admission decision is required.

For a non-intra-frequency handover request, both uplink and downlink decisions are required.

If there is a rate downsizing request, the RNC accepts it directly. For a rate upsizing request, both uplink and downlink admission control are required.

3.3.2 Power-based Admission Control on RRC Connection Setup Requests

The RNC performs loose or strict admission control on RRC connection setup requests.

If RSVDBIT8, RSVDBIT9, and RSVDBIT10 under the RsvdPara1 parameter in the ADD UCELLALGOSWITCH command are all set to 0 on the RNC, the RNC performs loose admission control on RRC connection setup requests. Otherwise, the RNC performs strict admission control on RRC connection setup requests.

Admission control is performed on RRC connection setup requests the same way as it is performed on RAB setup requests, except that the admission thresholds are different. This section only describes the admission thresholds for RRC connection setup requests in loose and strict admission control. For details about admission control for RAB setup, see section 3.3.3 "Power-based Admission Algorithm 1 for RAB Setup."

If load increase is considered when the RNC performs admission control on an RRC connection setup request, the RNC calculates the load increase based on the signaling radio bearer (SRB) rate of the RRC connection setup request. The SRB rate of an RRC connection setup request is set by running the SET URRCESTCAUSE command.

WCDMA RAN




3-6

Loose Admission Control

If an RRC connection setup request comes from emergency calls, detachments, or registrations, the RRC connection is set up directly.

If an RRC connection setup request comes from other services, admission control is performed as follows:

When UL_UU_OLC or DL_UU_OLC under the NBMLdcAlgoSwitch parameter is set to 1,

If the cell is overloaded, the RRC connection setup request is rejected.

If the cell is not overloaded, the uplink or downlink OLC triggering threshold (UlOlcTrigThd or DlOlcTrigThd) is used for admission control.

When UL_UU_OLC or DL_UU_OLC is set to 0, the uplink or downlink OLC triggering threshold (UlOlcTrigThd or DlOlcTrigThd) is used for admission control.

For details about the state of an overloaded cell and overload control (OLC), see the Load Control Feature Parameter Description.

Strict Admission Control

If an RRC connection setup request comes from emergency calls or detachments, the RRC connection is set up directly.

If an RRC connection setup request comes from other services, the RNC determines the admission threshold based on one of the following request causes:

RRC connection setup requests of real-time services

RRC connection setup requests of non-real-time services

RRC connection setup requests of other services (excluding real-time services, non-real-time services, emergency calls, and detachments)

The RNC determines the admission threshold using the following formulas:

Admission threshold for RRC of real-time services = Admission threshold offset for RRC of real-time services + UlNonCtrlThdForAMR (for the uplink) or DlConvAMRThd (for the downlink)

Admission threshold for RRC of non-real-time services = Admission threshold offset for RRC of non-real-time services + UlNonCtrlThdForOther (for the uplink) or DlOtherThd (for the downlink)

Admission threshold for RRC of other services = Admission threshold offset for RRC of other services + UlOlcTrigThd (for the uplink) or DlOlcTrigThd (for the downlink)

The offsets in these three formulas vary with the settings of RSVDBIT8, RSVDBIT9, and RSVDBIT10 under the RsvdPara1 parameter. See Table 3-1.

Table 3-1 Admission threshold offsets for three types of RRC connection setup request in strict admission control

Settings of RSVDBIT8, RSVDBIT9, and RSVDBIT10

Admission Threshold Offset for RRC of Real-Time Service

Admission Threshold Offset for RRC of Non-Real-Time Service

Admission Threshold Offset for RRC of Other Service

(0, 0, 1) 5% 5% 0%

(0, 1, 0) 0% 0% 0%

(0, 1, 1) -5% -5% -5%

WCDMA RAN




3-7

Settings of RSVDBIT8, RSVDBIT9, and RSVDBIT10

Admission Threshold Offset for RRC of Real-Time Service

Admission Threshold Offset for RRC of Non-Real-Time Service

Admission Threshold Offset for RRC of Other Service

(1, 0, 0) 5% 5% -15%

(1, 0, 1) 0% 0% -15%

(1, 1, 0) -5% -5% -20%

(1, 1, 1) 15% 10% -10%

3.3.3 Power-based Admission Algorithm 1 for RAB Setup

There are two types of power-based admission decisions based on algorithm 1: uplink and downlink.

The RNC performs admission control on services based on cell load. The measurement quantities relevant to cell load are processed and reported by the load measurement module of the RNC. For details about how measurement quantities relevant to cell load are measured and reported, see the section of load measurements in the Load Control Feature Parameter Description.

Uplink Power-based Admission Decisions for R99 Cells Based on Algorithm 1

In an R99 cell, uplink power-based admission decisions are made according to the RTWP-based total uplink load. The RTWP-based total uplink load is calculated in real time by the load measurement module of the RNC. It is represented by UL,R99-Total and calculated using the following formula:

UL,R99-Total = 1 PN/RTWP + UL,CCH

Where

PN is the received uplink background noise. It is set by the BackgroundNoise parameter. If the auto-adaptive background noise update algorithm is enabled, PN is updated in real time. For details about the auto-adaptive background noise update algorithm, see the Load Control Feature Parameter Description.

RTWP is the received total wideband power in the uplink. It is measured by the NodeB and reported to the RNC periodically.

UL,CCH is the reserved load on the uplink common channels. It is set by the UlCCHLoadFactor parameter.

Upon receiving a service access request, the RNC makes the uplink power-based admission decision for an R99 service. The procedure is as follows:

1. The RNC calculates the uplink load increase (UL) based on the initial admission rate of the service. For details about the initial admission rate, see the Load Control Feature Parameter Description.

2. If the sum of the RTWP-based total uplink load (UL,R99-Total) and the load increase caused by the new service (UL) is lower than or equal to the corresponding admission threshold (UlNonCtrlThdForAMR, UlNonCtrlThdForNonAMR, UlNonCtrlThdForOther, or UlNonCtrlThdForHo), the RNC admits the service. Otherwise, the RNC performs the next step.

When RSVDBIT11 under the RsvdPara1 parameter in the ADD UCELLALGOSWITCH command is set to 1, the RNC

uses the following admission threshold for AMR service setup, reconfiguration, or handover requests to increase the access success rate of AMR services:

WCDMA RAN




3-8

When the OLC algorithm switch (UL_UU_OLC under the NBMLdcAlgoSwitch parameter) is turned on, the uplink OLC triggering threshold (UlOlcTrigThd) is used as the admission threshold.

When the OLC algorithm switch (UL_UU_OLC under the NBMLdcAlgoSwitch parameter) is turned off, the admission

threshold is 100%.

3. The RNC checks whether the control RTWP anti-interference function switch (RTWP_RESIST_DISTURB under the NBMCacAlgoSwitch parameter) is turned on. If it is turned on, the RNC checks whether the total uplink load of ENU on the cell is lower than CellUlEquNumCapacity. If it is lower than CellUlEquNumCapacity, the RNC admits the service. Otherwise, the RNC rejects the access request. For details about the total uplink load of ENU on the cell, see section 3.3.4 "Power-based Admission Algorithm 2 for RAB Setup."

Uplink Power-based Admission Decisions for HSPA Cells Based on Algorithm 1

In an HSPA cell, uplink power-based admission decisions are made based on the following load

measurements:

The RTWP-based total uplink load, which is calculated in real time by the load measurement module

of the RNC. It is represented by UL,HSUPA-Total and calculated using the following formula:

UL,HSUPA-Total = 1 PN/RTWP + UL,CCH + HS-DPCCH

Where HS-DPCCH is the reserved load for the uplink HS-DPCCH. It is set by the

UlHsDpcchRsvdFactor parameter. The other variables are defined the same way as for an R99 cell

in "Uplink Power-based Admission Decisions for R99 Cells Based on Algorithm 1."

The uncontrollable uplink load, which is the load factor for the receive power of a cell excluding the

receive power used for scheduling services. It is represented by UL,NonCtrl and calculated using the

following formula:

UL,NonCtrl = UL,HSUPA-Total UL,Ctrl

Where UL,Ctrl is the controllable uplink load and equals the received scheduled E-DCH power share

(RSEPS). RSEPS is the ratio of the receive power of all scheduled users to RTWP in the current cell.

RSEPS is measured by the NodeB and periodically reported to the RNC.

The total uplink load for preferential admission of R99 services, which is represented by UL,R99Prefer-Total.

When the guaranteed bit rate (GBR) for HSUPA services is too high, the RTWP-based total uplink load

may also be too high, and therefore R99 service admission is difficult. In this case, UL,R99Prefer-Total

ensures that R99 services are preferentially admitted. It is calculated using the following formula:

UL,R99Prefer-Total = UL,NonCtrl + ThdHSUPAMaxGBP + UL,CCH + HS-DPCCH

Where ThdHSUPAMaxGBP is the maximum guaranteed load threshold for HSUPA services when the RNC

makes an admission decision on an R99 service. It is set by the HsupaMaxGBPThd parameter.

If the periodic measurement switch of the total receive power used for scheduling services on the E-DCH is turned off

(HSUPA_EDCH_RSEPS_MEAS under the NBMCacAlgoSwitch parameter is set to 0), the RNC performs admission control for the cell based on ENU. For details about ENU-based admission control, see section 3.3.4 "Power-based Admission Algorithm 2 for RAB Setup."

Upon receiving a service access request, the RNC performs the uplink power-based admission decision. The procedure is as follows:

1. The RNC calculates the uplink load increase (UL) based on the initial admission rate of the service.

2. The RNC determines whether to admit the service. If service admission succeeds, the RNC admits the service. If service admission fails, the RNC performs the next step. Note that the admission criteria vary with the bearer type in an HSPA cell, which is described in follow-up sections.

WCDMA RAN




3-9

3. The RNC checks whether the control RTWP anti-interference function switch (RTWP_RESIST_DISTURB under the NBMCacAlgoSwitch parameter) is turned on. If it is turned on, the RNC checks whether the total uplink load of ENU on the cell is lower than CellUlEquNumCapacity. If it is lower than CellUlEquNumCapacity, the RNC admits the service. Otherwise, the RNC rejects the access request. For details about the total uplink load of ENU on the cell, see section 3.3.4 "Power-based Admission Algorithm 2 for RAB Setup."

The admission criteria for different bearer types in an HSPA cell are as follows:

For the DCH RAB

If the bearer type is the DCH RAB, a service is admitted only when the following criteria are both met:

The sum of the uncontrollable uplink load (UL,NonCtrl) and the load increase caused by the new service

(UL) is lower than or equal to the corresponding admission threshold (UlNonCtrlThdForAMR,

UlNonCtrlThdForNonAMR, UlNonCtrlThdForOther, or UlNonCtrlThdForHo).

The sum of the RTWP-based total uplink load (UL,HSUPA-Total) and the load increase caused by the new

service (UL), or the sum of the total uplink load for preferential admission of R99 services

(UL,R99Prefer-Total) and the load increase caused by the new service (UL), is lower than or equal to

UlCellTotalThd.





threshold is 100%.

For the HSUPA RAB

If the bearer type is the HSUPA RAB, the CAC algorithm combines the PBR-based admission decision with the load-based admission decision. The RNC admits an HSUPA service if either PBR-based admission or load-based admission succeeds.

IMS signaling services carried on HSUPA RABs are admitted directly.

PBR-based admission decisions

The uplink provided bit rate (PBR) is the effective uplink throughput on all UEs corresponding to a scheduling priority indicator (SPI) successfully received by the NodeB. PBR is reported by the NodeB to the RNC periodically.

The RNC performs PBR-based admission control only when the HSUPA PBR measurement switch is turned on (HSUPA_PBR_MEAS under the NBMCacAlgoSwitch parameter is set to 1). If the sum of PBRs of some UEs is larger than the sum of their GBRs multiplied by a certain factor, the RNC decides that the QoS requirements of the cell are met. In this case, the RNC can admit new services. PBR-based service admission succeeds if any of the following criteria are met:

WCDMA RAN




3-10

Where

ThdL is the PBR threshold (HsupaLowPriorityUserPBRThd) for all HSUPA users whose scheduling priorities are lower than the priority of users to be admitted.

ThdE is the PBR threshold (HsupaEqualPriorityUserPBRThd) for all HSUPA users whose scheduling priorities are equal to the priority of users to be admitted.

ThdGE is the PBR threshold (HsupaHighPriorityUserPBRThd) for all HSUPA users whose scheduling priorities are higher than the priority of users to be admitted.

Load-based admission decisions

For HSUPA scheduling services, if the sum of the RTWP-based total uplink load (UL,HSUPA-Total) and

the load increase caused by the new service (UL) is lower than or equal to UlCellTotalThd,

load-based service admission succeeds. Otherwise, load-based service admission fails.

For HSUPA non-scheduling services, load-based service admission succeeds only when both of the

following criteria are met:

The sum of the RTWP-based total uplink load (UL,HSUPA-Total) and the load increase caused by the

new service (UL) is lower than or equal to UlCellTotalThd.

The sum of the uncontrollable uplink load (UL,NonCtrl) and the load increase caused by the new

service (UL) is lower than or equal to the corresponding admission threshold

(UlNonCtrlThdForAMR, UlNonCtrlThdForNonAMR, UlNonCtrlThdForOther, or

UlNonCtrlThdForHo).

Otherwise, load-based service admission fails.



When the OLC algorithm switch (UL_UU_OLC under the NBMLdcAlgoSwitch parameter) is turned on, the uplink OLC

triggering threshold (UlOlcTrigThd) is used as the admission threshold.


threshold is 100%.

Downlink Power-based Admission Decisions for R99 Cells Based on Algorithm 1

In an R99 cell, downlink power-based admission decisions are made according to the TCP-based total downlink load, which is calculated in real time by the load measurement module of the RNC. It is represented by DL,R99-Total and calculated using the following formula:

DL,R99-Total = TCP + DL,CCH

Where

TCP is equal to the transmitted carrier power (TCP), which is the ratio of the total transmitted power on one downlink carrier to the maximum transmission power (set by the MaxTxPower parameter).

DL,CCH is the reserved load on the downlink common channels. It is set by the DlCCHLoadRsrvCoeff parameter.

Upon receiving a service access request, the RNC makes the downlink power-based admission decision for an R99 service. The procedure is as follows:

1. The RNC calculates the downlink load increase (DL) based on the initial admission rate of the service and the pilot signal quality the user receives.

WCDMA RAN




3-11

2. If the TCP-based total downlink load (DL,R99-Total) is lower than or equal to the corresponding

admission threshold (DlConvAMRThd, DlConvNonAMRThd, DlOtherThd, or DlHOThd), the RNC

admits the service. Otherwise, the RNC rejects the service.



When the OLC algorithm switch (DL_UU_OLC under the NBMLdcAlgoSwitch parameter) is turned on, the downlink OLC triggering threshold (DlOlcTrigThd) is used as the admission threshold.

When the OLC algorithm switch (DL_UU_OLC under the NBMLdcAlgoSwitch parameter) is turned off, the admission

threshold is 100%.

Downlink Power-based Admission Decisions for HSPA Cells Based on Algorithm 1

In an HSPA cell, downlink power-based admission decisions are made based on the following load measurements:

TCP-based total downlink load, which is represented by DL,HSDPA-Total and calculated using the following formula:

DL,HSDPA-Total = TCP + DL,CCH + DL,HSUPARes

Where DL,HSUPARes is the power load reserved for HSUPA downlink control channels

(E-AGCH/E-RGCH/E-HICH). It is set by the DlHSUPARsvdFactor parameter. The other variables are

defined the same way as for an R99 cell in "Downlink Power-based Admission Decisions for R99 Cells

Based on Algorithm 1."

Downlink non-HSPA power load, which is represented by DL,NonHSPA. It is the ratio of the total

transmitted power of the codes not used for HS-PDSCH/HS-SCCH/E-AGCH/E-RGCH/E-HICH

transmission on one downlink carrier to the maximum transmission power (set by the MaxTxPower

parameter). DL,NonHSPA is measured by the NodeB and periodically reported to the RNC.

Load of HSDPA power requirement for GBR (HSDPA GBP), which is represented by DL,GBP and calculated based on the GBR of HSDPA users in the cell. The NodeB periodically reports DL,GBP to the RNC.

HSDPA GBP-based total downlink load, which is represented by DL,GBP-Total and calculated using the following formula:

DL,GBP-Total = DL,NonHSPA + min (DL,GBP + DL,HSUPARes, DL,MaxHSPA) + DL,CCH

Where DL,MaxHSPA is the threshold for the maximum available HSDPA power. It is calculated based on the HspaPower parameter.

The total downlink load for preferential admission of R99 services, which is represented by

DL,R99Prefer-Total. When the GBR for HSDPA services is too high, the HSDPA GBP-based total downlink

load may also be too high, and therefore R99 service admission is difficult. In this case, DL,R99Prefer-Total ensures that R99 services are preferentially admitted. It is calculated using the following formula:

DL,R99Prefer-Total = DL,NonHSPA + ThdHSDPAMaxGBP + DL,HSUPARes + DL,CCH

Where ThdHSDPAMaxGBP is the maximum guaranteed load threshold for HSDPA services when the RNC

makes an admission decision on an R99 service. It is set by the HsdpaMaxGBPThd parameter.

Upon receiving a service access request, the RNC performs the downlink power-based admission decision. The procedure is as follows:

1. The RNC calculates the downlink load increase (DL) based on the initial admission rate of the service and the pilot signal quality the user receives.

WCDMA RAN




3-12

2. The RNC determines whether to admit the service. The admission criteria vary with the bearer type in an HSPA cell.

The admission criteria for different bearer types in an HSPA cell are as follows:

For the DCH RAB

If the bearer type is the DCH RAB, a service is admitted only when the following criteria are both met:

1. The sum of the downlink non-HSPA power load (DL,NonHSPA) and the load increase caused by the new service (DL) is lower than or equal to the corresponding admission threshold (DlConvAMRThd, DlConvNonAMRThd, DlOtherThd, or DlHOThd).

2. The sum of the TCP-based total downlink load (DL,HSDPA-Total) and the load increase caused by the

new service (DL), the sum of the total downlink load based on the guaranteed power for HSDPA

services (DL,GBP-Total) and the load increase caused by the new service (DL), or the sum of the total downlink load for preferential admission of R99 services (DL,R99Prefer-Total) and the load increase caused by the new service (DL) is lower than or equal to the threshold for the total downlink power

of the cell (DlCellTotalThd). Otherwise, the RNC rejects the service.





threshold is 100%.

If the current cell supports DC-HSDPA, the current total power of the DC-HSDPA cell group must also be lower than the sum of the total downlink power threshold of the primary cell and that of the secondary cell for DCH RAB admission.

For the HSDPA RAB

If the bearer type is the HSDPA RAB, the CAC algorithm combines the PBR-based admission control with the load-based admission control. The RNC admits an HSDPA service if either PBR-based admission or load-based admission succeeds.

PBR-based admission decisions

The downlink PBR is the effective downlink throughput on all UEs corresponding to an SPI successfully sent by the NodeB. PBR is reported by the NodeB to the RNC periodically.

The RNC performs PBR-based admission control only when the HSDPA PBR measurement switch is turned on (HSDPA_PBR_MEAS under the NBMCacAlgoSwitch parameter is set to 1). If the sum of PBRs of some UEs is larger than the sum of their GBRs multiplied by a certain factor, the RNC decides that the QoS requirements of the cell are met. In this case, the RNC can admit new services. PBR-based service admission succeeds if equation a (for streaming services) or equation b (for BE services) is satisfied:

a.

b.

Where

WCDMA RAN




3-13

PBRstrm is the provided bit rate of all existing streaming services.

Thdhsdpa-str is the admission threshold of the PBR-based decision for streaming services (HsdpaStrmPBRThd).

PBRbe is the provided bit rate of all existing BE services.

Thdhsdpa-be is the admission threshold of the PBR-based decision for BE services (HsdpaBePBRThd).

Load-based admission decisions

Load-based service admission succeeds only when both of the following criteria are met:

The sum of the HSDPA GBP load (DL,GBP) and the load increase caused by the new service (DL) is

lower than or equal to the threshold for the maximum available HSDPA power, which is equal to 110

(-HspaPower/10).

The sum of the TCP-based total downlink load (DL,HSDPA-Total) and the load increase caused by the

new service (DL), or the sum of the HSDPA GBP-based total downlink load (DL,GBP-Total) and the

load increase caused by the new service (DL) is lower than or equal to the threshold for the total

downlink power of the cell (DlCellTotalThd).

Otherwise, load-based service admission fails.





threshold is 100%.

If the current cell supports DC-HSDPA, the total power of the DC-HSDPA cell group must be lower than the sum of the downlink total power threshold of the primary cell and that of the secondary cell for HSDPA RAB admission.

Conversational services in the PS domain carried on HSPA RABs can be considered as streaming services in admission control.

For the DC-HSDPA RAB

If the bearer type is the DC-HSDPA RAB, admission control is based on the power of the DC-HSDPA cell group because the RAB is set up on both carriers.

The RNC admits DC-HSDPA RABs in the following situations:

PBR-based service admission in the DC-HSDPA cell group succeeds. PBR-based admission control in the DC-HSDPA cell group is similar to that in the SC-HSDPA cell. The difference between them is that users selected during an admission decision are DC-HSDPA users in the DC-HSDPA cell group, not SC-HSDPA users.

Load-based service admission in the DC-HSDPA cell group succeeds. This means that the total downlink load factor of the DC-HSDPA cell group is lower than the sum of the total downlink load threshold of the primary cell and that of the secondary cell.

For HSUPA Control Channels

The power for downlink control channels (E-AGCH/E-RGCH/E-HICH) is specified by the DlHSUPARsvdFactor parameter. Therefore, power-based admission control is not required on these channels.

WCDMA RAN




3-14

For MBMS

For details about MBMS, see the MBMS Feature Parameter Description.


There are two types of power-based admission decisions based on algorithm 2: uplink and downlink.

The ENU of MBMS downlink control channels (MICH and MCCH) is reserved. Therefore, power-based admission is not performed on these channels.

The ENU of HSUPA downlink control channels (E-AGCH, E-RGCH, and E-HICH) is reserved by DlHSUPARsvdFactor. Therefore, power-based admission is not performed on these channels.

Equivalent Number of Users

When the activation factor is 100%, a 12.2 kbit/s AMR service is defined as one ENU. The following aspects are considered when the ENU is calculated:

Cell type (a typical urban cell or a suburban cell)

Traffic QoS, which is the Block Error Rate (BLER)

Target number of retransmissions

The activity factor of the traffic type, which can be set with the SET UADMCTRL command.

Table 3-2 describes the ENU references for some services in typical scenarios. Configurations in typical scenarios are as follows:

The cell is a typical urban cell.

The target BLER of R99 users in the cell is 1%.

Target number of retransmissions:

10% for 2 ms TTI HSUPA users

1% for 10 ms TTI HSUPA users

Activation factors for different service types:

Activation factor SRB = 10%

Activation factor for AMR 12.2 kbit/s services = 50%

Activation factor for DCH PS services = 10%

Activation factor HSPA PS services = 100%

Table 3-2 ENU references in the typical scenarios

Service ENU

Uplink for DCH Downlink for DCH HSDPA 2 ms TTI HSUPA

10 ms TTI HSUPA

3.4 kbit/s SIG 0.2847 0.0420 0.0279 0.3107 0.1369

13.6 kbit/s SIG 0.5057 0.1115 0.0738 0.36 0.1655

3.4 kbit/s + 12.2 kbit/s

0.8196 0.5420 - 2.0242 1.0869

3.4 kbit/s + 8 kbit/s (PS)

0.7548 0.1044 0.545 3.5098 1.7611

WCDMA RAN




3-15

Service ENU

Uplink for DCH Downlink for DCH HSDPA 2 ms TTI HSUPA

10 ms TTI HSUPA


0.6500 0.1248 0.8749 3.8713 1.9786


0.6228 0.2187 1.463 4.5856 2.4106


0.7566 0.3252 2.5545 5.9806 3.2625


0.9248 0.5926 4.6851 8.6430 4.9192


1.0305 0.6615 5.2225 9.2279 5.2463


1.4399 1.0489 9.1193 13.1063 7.4698


2.1150 1.5523 13.9332 17.1227 9.8773

In Table 3-2,

HSDPA (3.4 kbit/s SIG or 13.6kbit/s SIG) indicates the ENU when SRB over HSDPA is used.

HSDPA (3.4 kbit/s + n kbit/s) indicates the ENU when SRB over DCH and TRB over HSDPA are used.

HSUPA (3.4 kbit/s SIG or 13.6kbit/s SIG) indicates the ENU when SRB over HSUPA is used.

HSUPA (3.4 kbit/s + n kbit/s) indicates the ENU when SRB over DCH and TRB over HSUPA are used.

Uplink ENU Resource Admission Decisions

In the uplink, ENU-based admission decisions are made based on the following load measurements:

Uplink total ENU load, which is represented by UL,ENU and calculated using the following formula:

UL,ENU = ENUUL,Total/ENUUL,Max + UL,CCH

Where

ENUUL,Total is the sum of ENUs corresponding to the RABs in a cell.

ENUUL,Max is the maximum ENU of a cell. It is set by the UlTotalEqUserNum parameter.

UL,CCH is the reserved load on the uplink common channels. It is set by the UlCCHLoadFactor parameter.

The total uplink load of ENU for preferential admission of R99 services, which is represented by UL,R99Prefer-ENU. When the GBR for HSUPA services is too high, the total uplink load of ENU may also be too high, and therefore R99 service admission is difficult. In this case, UL,R99Prefer-ENU ensures that R99 services are preferentially admitted. It is calculated using the following formula:

UL,R99Prefer-ENU = UL,DCH_ENU + Thd HSUPAMaxGBP Where

UL,DCH_ENU is the ENU load of all DCH RABs in a cell. It is the ratio of the sum of ENUs for all DCH RABs to the maximum ENU in a cell (UlTotalEqUserNum).

WCDMA RAN




3-16

Where ThdHSUPAMaxGBP is the maximum guaranteed load threshold for HSUPA services when the RNC makes an admission decision on an R99 service. It is set by the HsupaMaxGBPThd parameter.

Upon receiving a service access request, the RNC makes the uplink ENU-based admission decision.

If a cell is in the OLC state triggered by the RTWP:

The system checks whether the uplink total ENU load (UL,ENU) of the cell is lower than CellUlEquNumCapacity if the control RTWP anti-interference function switch (RTWP_RESIST_DISTURB under the NBMCacAlgoSwitch parameter) is turned on. If it is lower than CellUlEquNumCapacity, the RNC admits the service. Otherwise, the RNC rejects the access request.

The RNC rejects the access request if the control RTWP anti-interference function is disabled.

If a cell is not in the OLC state, the RNC makes the uplink ENU-based admission decision. The procedure is as follows:

1. The RNC estimates the ENU load (UL,ENU) based on the initial admission rate of the service.

2. The RNC determines whether to admit the service.

If the bearer type is the DCH RAB, the RNC admits a service when the sum of the uplink total ENU

load (UL,ENU) and the ENU load increase caused by the new service (UL,ENU) is lower than or equal to the corresponding admission threshold (UlNonCtrlThdForAMR, UlNonCtrlThdForNonAMR,

UlNonCtrlThdForOther, or UlNonCtrlThdForHo), or when the sum of the total uplink ENU load for

preferential admission of R99 services (UL,R99Prefer-ENU) and the ENU load increase caused by the

new service (UL,ENU) is lower than or equal to UlCellTotalThd. Otherwise, the RNC rejects the

access request.

If the bearer type is the HSUPA RAB, the RNC admits a service only when the sum of the uplink total

ENU load (UL,ENU) and the ENU load increase caused by the new service (UL,ENU) is lower than or equal to the corresponding admission threshold (UlNonCtrlThdForAMR,

UlNonCtrlThdForNonAMR, UlNonCtrlThdForOther, or UlNonCtrlThdForHo). Otherwise, the

RNC rejects the access request.





threshold is 100%.

Downlink ENU Resource Admission Decisions

In the downlink, ENU-based admission decisions are made based on the following load measurements:

Downlink total ENU load, which is represented by DL,ENU and calculated using the following formula:

DL,ENU = ENUDL,Total/ENUDL,Max + DL,CCH Where

ENUDL,Total is the sum of ENUs corresponding to the RABs in a cell.

ENUDL,Max is the maximum ENU of a cell. It is set by the DlTotalEqUserNum parameter.

DL,CCH is the reserved load on the downlink common channels. It is set by the DlCCHLoadRsrvCoeff parameter.

WCDMA RAN




3-17

The total downlink load for preferential admission of R99 services, which is represented by

DL,R99Prefer-ENU. When the GBR for HSDPA services is too high, the HSDPA GBP-based total downlink load may also be too high, and therefore R99 service admission is difficult. In this case, DL,R99Prefer-ENU ensures that R99 services are preferentially admitted. It is calculated using the following formula:

DL,R99Prefer-ENU = DL,DCH_ENU + ThdHSDPAMaxGBP Where

DL,DCH_ENU is the ENU load of all DCH RABs in a cell. It is the ratio of the sum of ENUs for all DCH RABs to the maximum ENU in a cell (DlTotalEqUserNum).

ThdHSDPAMaxGBP is the maximum guaranteed load threshold for HSDPA services when the RNC

makes an admission decision on an R99 service. It is set by the HsdpaMaxGBPThd parameter.

Upon receiving a service access request, the RNC makes the downlink ENU-based admission decision.

For non-DC-HSDPA RABs

The RNC estimates the ENU load (DL,ENU) of the service based on the initial admission rate, and

then makes the ENU-based admission decision.

For DCH RABs, if the sum of the downlink total ENU load (DL,ENU) and the ENU load increase caused by the new service (DL,ENU) is lower than or equal to the corresponding admission threshold

(DlConvAMRThd, DlConvNonAMRThd, DlOtherThd or DlHOThd), or if the sum of the total

downlink load for preferential admission of R99 services (DL,R99Prefer-ENU) and the ENU load increase caused by the new service (DL,ENU) is lower than or equal to DlCellTotalThd, the RNC admits the

service. Otherwise, the RNC rejects the access request.

For HSDPA RABs, if the sum of the downlink total ENU load (DL,ENU) and the ENU load increase caused by the new service (DL,ENU) is lower than or equal to the corresponding admission threshold

(DlConvAMRThd, DlConvNonAMRThd, DlOtherThd or DlHOThd), the RNC admits the service.

Otherwise, the RNC rejects the access request.





threshold is 100%.

For DC-HSDPA RABs

The admission succeeds when the total ENU of the DC-HSDPA cell group divided by the maximum ENU of the DC-HSDPA cell group is lower than the sum of admission thresholds of the primary cell and that of the secondary cell.


Algorithm 3 is similar to algorithm 1. The only difference is that the estimated load increase in algorithm 3 is always set to 0.

Based on the current cell load, the RNC determines whether the cell load exceeds the threshold, with the estimated load increase set to 0. If the cell load exceeds the threshold, the RNC rejects the access request. If not, the RNC admits the service.

WCDMA RAN




3-18

3.4 CAC Based on NodeB Credit Resources

NodeB credit resource-based admission is optional for admission control. This admission mode takes effect only when NODEB_CREDIT_CAC_SWITCH under the CacSwitch parameter and CRD_ADCTRL under the NBMCacAlgoSwitch parameter are selected.

3.4.1 NodeB Credit Resources

The NodeB credit resource is a concept on the RNC side. It is referred to as the channel element (CE) on the NodeB side.

CEs are used to measure the channel demodulation capability of NodeBs. CEs are classified into uplink and downlink CEs.

One uplink CE needs to be consumed by an uplink 12.2 kbit/s voice service (SF = 64) plus 3.4 kbit/s signaling traffic.

One downlink CE needs to be consumed by a downlink 12.2 kbit/s voice service (SF = 128) plus 3.4 kbit/s signaling traffic.

If only 3.4 kbit/s signaling traffic is carried on a DCH or HSPA channel, one CE is still needed. CEs have been reserved for common and HSDPA-related channels. For details about CEs and CE consumption of different types of service, see the CE Resource Management Feature Parameter Description.

NodeB credit resource-based admission is implemented at NodeB level, local cell group (LCG) level (if any), and local cell (LC) level. Cells in an LCG share the CEs of the LCG in the uplink. The NodeB sends the RNC an audit response message, reporting the CE capability of the three levels. The NodeB considers physical and licensed CEs when reporting the CE capability to the RNC.

The NodeB-level CEs are the licensed CEs supported by the NodeB.

In the uplink, the number of LCG-level CEs are the smaller one between the number of LCG-level physical CEs and the number of NodeB-level licensed CEs. In the downlink, the number of LCG-level CEs are the sum of downlink CEs on all boards of the LCG.

In the uplink, the LC-level CEs are the physical CEs of the uplink resource group to which the cell belongs. In the downlink, the LC-level CEs are the physical CEs of the baseband processing board to which the cell belongs.

The relationship between NodeB credit resources and CEs is as follows:

In the uplink, the quantity of NodeB credit resources is twice that of CEs.

In the downlink, the quantity of NodeB credit resources equals that of CEs.

The RNC calculates the remaining NodeB credit resources based on the reported CE capability, relationship between NodeB credit resources and CEs, and the CE consumption rule. The RNC implements admission control based on the calculation result. Uplink and downlink CEs are independent from each other. Therefore, NodeB credit resource-based admission is implemented separately in the uplink and downlink.

3.4.2 NodeB Credit Resource-based Admission Decisions

In NodeB credit resource-based admission, the admission criteria vary with the service request.

NodeB credit resource-based admission is not required for common and HSDPA-related channels because CEs have been reserved for these channels.

WCDMA RAN




3-19

RRC Connection Setup Requests

For an RRC connection setup request, NodeB credit resource-based admission is implemented as follows:

When RSVDBIT11 under the RsvdPara1 parameter in the ADD UCELLALGOSWITCH command is set to 0, NodeB credit resource-based admission succeeds if the available credit resources of the local cell, local cell group (if any), and NodeB are sufficient for setting up an RRC connection.

When RSVDBIT11 under the RsvdPara1 parameter in the ADD UCELLALGOSWITCH command is set to 1, the RNC implements NodeB credit resource-based admission based on the cause carried in the RRC connection setup request:

If the cause is "Emergency Call" or "Detach", NodeB credit resource-based admission succeeds if the available credit resources are sufficient.

For any other cause, the RNC must ensure that the available credit resources of the local cell, local cell group (if any), and NodeB exceed the reserved credit resources upon admitting an RRC connection setup request. The reserved credit resources are calculated using SF which is specified by RSVDBIT12 under the RsvdPara1 parameter in the ADD UCELLALGOSWITCH command.

a. If RSVDBIT12 under the RsvdPara1 parameter is set to 0, SF64 is used for the uplink and SF128 is used for the downlink.

b. If RSVDBIT12 under the RsvdPara1 parameter is set to 1, SF16 is used for the uplink and SF32 is used for the downlink.

Handover Service Requests

For a handover service request, NodeB credit resource-based admission succeeds if the available credit resources of the local cell, local cell group (if any), and NodeB are sufficient for the service to be admitted.

PS Service/CS Service (Non-AMR Service) Requests

For PS or CS service (non-AMR service) requests, the RNC must ensure that the available credit resources of the local cell, local cell group (if any), and NodeB exceed the reserved credit resources upon admitting a new service. The reserved credit resources are calculated using SF which is specified by the UlHoCeResvSf (for the uplink) or DlHoCeCodeResvSf (for the downlink) parameter.

AMR Service Requests

For AMR service requests,

When RSVDBIT11 under the RsvdPara1 parameter in the ADD UCELLALGOSWITCH command is set to 0, the RNC must ensure that the available credit resources of the local cell, local cell group (if any), and NodeB exceed the reserved credit resources upon admitting a new service. The reserved credit resources are calculated using SF which is specified by the UlHoCeResvSf (for the uplink) or DlHoCeCodeResvSf (for the downlink) parameter.

When RSVDBIT11 under the RsvdPara1 parameter in the ADD UCELLALGOSWITCH command is set to 1, NodeB credit resource-based admission succeeds if the available credit resources of the local cell, local cell group (if any), and NodeB are sufficient for the service to be admitted.

3.5 CAC Based on Iub Resources

Iub resource-based admission control is mandatory when a new service attempts to access the network.

For details about resource-based admission at the transport layer over the Iub interface, see the Transmission Resource Management Feature Parameter Description.

WCDMA RAN




3-20

3.6 CAC Based on the Number of HSPA Users

3.6.1 CAC for HSDPA Users

HSDPA admission control is based on the number of HSDPA users.

When a new HSDPA service attempts to access the network, the algorithm admits the service if the following conditions are met:

The number of HSDPA users in the cell does not exceed the maximum value specified by the MaxHsdpaUserNum parameter.

The number of HSDPA users in the cell does not exceed the licensed number of users.

The number of HSDPA users in NodeB does not exceed the maximum value specified by the NodeBHsdpaMaxUserNum parameter.

Otherwise, the HSDPA service performs Directed Retry Decision (DRD) to access one of the cells that support blind handovers. If none of these cells can be accessed, the HSDPA service is degraded to an R99 service and then attempts to access a cell. For details about DRD, see the Directed Retry Decision Feature Parameter Description.

3.6.2 CAC for HSUPA Users

HSUPA admission control is based on the number of HSUPA users.

When a new HSUPA service attempts to access the network, the algorithm admits the service if the following conditions are met:

The number of HSUPA users in the cell does not exceed the maximum value specified by the MaxHsupaUserNum parameter.

The number of HSDPA users in the cell does not exceed the licensed number of users.

The number of HSUPA users in NodeB does not exceed the maximum value specified by the NodeBHsupaMaxUserNum parameter.

Otherwise, the HSUPA service performs Directed Retry Decision (DRD) to access one of the cells that support blind handovers. If none of these cells can be accessed, the HSUPA service is degraded to an R99 service and then attempts to access a cell. For details about DRD, see the Directed Retry Decision Feature Parameter Description.

WCDMA RAN

Call Admission Control 4 Parameters



4-1

4 Parameters

Table 4-1 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

Unit: 0.1dBm

Default Value: 61

CacSwitch BSC6900 SET UCACALGOSWITCH(Optional)

Meaning: The parameter values are described as follows:

NODEB_CREDIT_CAC_SWITCH: The system performs CAC based on the usage state of NodeB credit. When the NodeB's credit is not enough, the system rejects new access requests.

GUI Value Range: NODEB_CREDIT_CAC_SWITCH(NodeB Credit CAC Switch)

Actual Value Range: NODEB_CREDIT_CAC_SWITCH

Unit: None

Default Value: None

CellUlEquNumCapacity



Meaning: Used to check whether the number of equivalent users is overlarge in a cell. If the rate of equivalent users to total equivalent users allowed in the cell is greater than this parameter, the number of equivalent users will be judged as overlarge, Otherwise the number of equivalent users will not be judged as overlarge. If the number of equivalent users is not overlarge, and the switch of RTWP anti-interference algorithm is enabled, the RTWP anti-interference algorithm is validated. Admission requests will be accepted even when the RTWP value is great, and related OLC operations will be cancelled.


Actual Value Range: 0~1

Unit: %

Default Value: 40

DlCCHLoadRsrvCoeff

BSC6900 ADD UCELLCAC(Optiona

Meaning: Different admission policies are used for dedicated channel and common channel users. For common channel users, resources instead of separate

WCDMA RAN




4-2


l)


power admission decision are reserved. For dedicated channel users, according to the current load factor and the characteristics of the new call, the CAC algorithm predicts the new TX power with the assumption of admitting the new call, then plus with the premeditated common channel DL load factor to get the predicted DL load factor. Then, compare it with the DL admission threshold. If the value is not higher than the threshold, the call is admitted; otherwise, rejected.



Unit: %

Default Value: 0

DlCellTotalThd BSC6900 ADD UCELLCAC(Optional)


Meaning: Admission threshold of the total cell downlink power. If the value is too high, too many users will be admitted. However, the throughput of a single user is easy to be limited. If the value is too low, cell capacity will be wasted.



Unit: %

Default Value: 90

DlConvAMRThd



Meaning: The percentage of the conversational AMR service threshold to the 100% downlink load. It is applicable to algorithm 1 and algorithm 2. The parameter is used for controlling the AMR service admission. That is, when an AMR service is accessing, the RNC evaluates the measurement value of the downlink load after the service is accessed. If the DL load of a cell is higher than this threshold after the access of an AMR speech service, this service will be rejected. If the DL load of a cell will not be higher than this threshold, this service will be admitted.

The DL load factor thresholds include parameters of [DL threshold of Conv AMR service], [DL threshold of Conv non_AMR service], [DL handover access threshold] and [DL threshold of other services]. The four parameters can be used to limit the proportion between the conversational service, handover user and other services in a specific cell, and to guarantee the access priority of the conversational AMR service.



Unit: %

Default Value: 80

DlConvNonAM BSC6900 ADD UCELLCAC(Optiona

Meaning: The percentage of the conversational non-AMR service threshold to the 100% downlink load.

WCDMA RAN




4-3


RThd l)


It is applicable to algorithm 1 and algorithm 2. The parameter is used for controlling the non-AMR service admission. That is, when a non-AMR service is accessing, the RNC evaluates the measurement value of the downlink load after the service is accessed. If the DL load of a cell is higher than this threshold after the access of a non-AMR speech service, this service will be rejected. If the DL load of a cell will not be higher than this threshold, this service will be admitted.

The DL load factor thresholds include parameters of [DL threshold of Conv AMR service], [DL threshold of Conv non_AMR service], [DL handover access threshold] and [DL threshold of other services]. The four parameters can be used to limit the proportion between the conversational service, handover user and other services in a specific cell, and to guarantee the access priority of the conversational non-AMR service.



Unit: %

Default Value: 80

DlHOThd BSC6900 ADD UCELLCAC(Optional)


Meaning: The percentage of the handover service admission threshold to the 100% downlink load. It is applicable to algorithm 1 and algorithm 2. The parameter is used for controlling the handover admission. That is, when a service is handing over to a cell, the RNC evaluates the measurement value of the downlink load after the service is accessed. If the DL load of a cell is higher than this threshold after the access, this service will be rejected. If the DL load of a cell will not be higher than this threshold, this service will be admitted.



Unit: %

Default Value: 85

DlHSUPARsvdFactor



Meaning: Reserved DL power factor for HSUPA user. The higher the value is, the more resources reserved for the HSUPA control channel, which leads to resource waste. If the value is too low, HSUPA user quality may be impacted.



Unit: %

Default Value: 0

WCDMA RAN




4-4


DlHoCeCodeResvSf



Meaning: Some cell resources can be reserved for handover UEs to guarantee handover success rate and improve access priority of handover services. This parameter defines the quantity of downlink code and CE resources reserved for handover. SFOFF refers to that no resources is reserved. SF32 refers to that a code resource with SF = 32 and its corresponding credit resource are reserved.

GUI Value Range: SF4(SF4), SF8(SF8), SF16(SF16), SF32(SF32), SF64(SF64), SF128(SF128), SF256(SF256), SFOFF(SFOFF)

Actual Value Range: SF4, SF8, SF16, SF32, SF64, SF128, SF256, SFOFF

Unit: None

Default Value: SF32

DlOlcTrigThd BSC6900 ADD UCELLLDM(Optional)

MOD UCELLLDM(Optional)

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.



Unit: %

Default Value: 95

DlOtherThd BSC6900 ADD UCELLCAC(Optional)


Meaning: The percentage of other service thresholds to the 100% downlink load. The services refer to other admissions except the conversational AMR service, conversational non-AMR service, and handover scenarios. It is applicable to algorithm 1 and algorithm 2. The parameter is used for controlling other service admissions. That is, when a service is accessing, the RNC evaluates the measurement value of the downlink load after the service is accessed. If the DL load of a cell is higher than this threshold after the access of a service, this service will be rejected. If the DL load of a cell will not be higher than this threshold, this service will be admitted.

The DL load factor thresholds include parameters of [DL threshold of Conv AMR service], [DL threshold of Conv non_AMR service], [DL handover access threshold] and [DL threshold of other services]. The four parameters can be used to limit the proportion

WCDMA RAN




4-5


between the conversational service, handover user and other services in a specific cell, and to guarantee the access priority of other services.



Unit: %

Default Value: 75

DlTotalEqUserNum



Meaning: When the algorithm 2 is used, this parameter defines the total equivalent user number corresponding to the 100% downlink load. The parameter should be related to the admission threshold and actual condition of the network.



Unit: None

Default Value: 80

HsdpaBePBRThd



Meaning: Average throughput admission threshold of the HSDPA best effort traffic. If the sum of PBR of all the accessed HSDPA BE users is lower than the average throughput admission threshold of the HSDPA BE service multiplied by the sum of GBR of all the accessed HSDPA BE users, it indicates that the QoS of the accessed users cannot be satisfied and new HSDPA BE services are not allowed. Otherwise, the QoS can be satisfied and new HSDPA BE services are allowed.



Unit: %

Default Value: 30

HsdpaMaxGBPThd



Meaning: Threshold of the maximum guaranteed power for HSDPA users. This threshold limits the power that can be used by HSDPA users. Thus, some power resources are reserved for DCH users to ensure their network access.



Unit: %

Default Value: 100

HsdpaStrmPBRThd


MOD UCELLCAC(Optiona

Meaning: Average throughput admission threshold of the HSDPA streaming service. If the sum of PBR of all the accessed streaming users is lower than the average throughput admission threshold of the HSDPA streaming service multiplied by the sum of GBR of all the accessed streaming users, it indicates that the

WCDMA RAN




4-6


l) QoS of the accessed users cannot be satisfied and new HSDPA streaming services are not allowed. Otherwise, the QoS can be satisfied and new HSDPA streaming services are allowed.



Unit: %

Default Value: 70

HspaPower BSC6900 ADD UCELLHSDPA(Optional)

MOD UCELLHSDPA(Optional)

Meaning: This parameter specifies the offset between the total HSPA power and the maximum transmission power of a cell. The total HSPA power is the maximum value of HSPA dynamical power can be adjusted. For details about this parameter, refer to 3GPP TS 25.308.

GUI Value Range: -500~0

Actual Value Range: -50~0

Unit: 0.1dB

Default Value: 0

HsupaEqualPriorityUserPBRThd



Meaning: Threshold of all the HSUPA user PBR whose schedule priority is the same as that of users to be admitted.



Unit: %

Default Value: 100

HsupaHighPriorityUserPBRThd



Meaning: Threshold of all the HSUPA user PBR whose schedule priority is higher than that of users to be admitted.



Unit: %

Default Value: 100

HsupaLowPriorityUserPBRThd



Meaning: Threshold of all the HSUPA user PBR whose schedule priority is lower than that of users to be admitted.



Unit: %

Default Value: 100

HsupaMaxGBPThd


MOD UCELLCAC(Optiona

Meaning: Threshold of the maximum guaranteed power for HSUPA users. This threshold limits the power that can be used by HSUPA users. Thus, some power resources are reserved for DCH users to ensure their network access.

WCDMA RAN




4-7


l) GUI Value Range: 0~100


Unit: %

Default Value: 100

MaxHsdpaUserNum



Meaning: Maximum number of users supported by the HSDPA

channel. The user in this parameter refers to the user with

services on the HSDPA channel, regardless of the number of RABs

carried on the HSDPA channel. Maximum HSDPA user number cannot

exceed the HSDPA capability of the NodeB product, In practice,

the value can be set based on the cell type and the richness of

the available HSDPA power and code resources.



Unit: None

Default Value: 64

MaxHsupaUserNum



Meaning: Maximum number of users supported by the HSUPA

channel. The user in this parameter refers to the user with

services on the HSUPA channel, regardless of the number of RABs

carried on the HSUPA channel. Maximum HSUPA user number cannot

exceed the HSUPA capability of the NodeB product, In practice,

the value can be set based on the cell type and the richness of

the available HSUPA power and code resources.



Unit: None

Default Value: 20

MaxTxPower BSC6900 ADD UCELLSETUP(Optional)

ADD UCELLQUICKSETU

Meaning: Sum of the maximum transmit power of all DL channels in a cell. For detailed information of this parameter, refer to 3GPP TS 25.433.



WCDMA RAN




4-8


P(Optional)

MOD UCELL(Optional)

ADD UIMBCELLSETUP(Optional)

ADD UIMBCELLQUICKSETUP(Optional)

Unit: 0.1dBm

Default Value: 430

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. This swtich does not work when uplink is beared on

HSUPA and downlink is beared on HSDPA. 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. This switch does not work when uplink is beared on

HSUPA and downlink is beared on HSDPA. 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

WCDMA RAN




4-9


is abnormal.

FACH_UU_ADCTRL: Admission control switch for the FACH on the Uu

interface. This switch determines whether to admit a user in

the RRC state on the CELL_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 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.Parameter withdrawal

explanation:The current version supports synchronization and

delivery of the setting of this parameter. The RNC, however,

does not use this parameter any longer. Later

WCDMA RAN




4-10


versions will not

support this parameter. Therefore, users should not use this

parameter. After this parameter is withdrawn, the RNC always

performs cell resource admission on Fast Dormancy users. If

cell resources are insufficient, Fast Dormancy users cannot

enter the CELL_FACH state. If switches above are selected, the