intra-rat huawei algo and parametrs

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eRAN

eRAN7.0

Intra-RAT Mobility Management in ConnectMode Feature Parameter Description

Issue 03



Date 2014-09-30

HUAWEI TECHNOLOGIES CO., LTD.

Copyright © Huawei Technologies Co., Ltd. 2015. All rights reserved.No part of this document may be reproduced or transmitted in any form or by any means without prior writtenconsent 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.

NoticeThe purchased products, services and features are stipulated by the contract made between Huawei and thecustomer. All or part of the products, services and features described in this document may not be within thepurchase scope or the usage scope. Unless otherwise specified in the contract, all statements, information, andrecommendations in this document are provided "AS IS" without warranties, guarantees or representations ofany kind, either express or implied.The information in this document is subject to change without notice. Every effort has been made in thepreparation of this document to ensure accuracy of the contents, but all statements, information, andrecommendations in this document do not constitute a 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]

Contents

1 About This Document

1.1 Scope

1.2 Intended Audience

1.3 Change History

1.4 Differences Between eNodeB Types

2 Overview

2.1 Definition

2.2 Benefits

2.3 Architecture

3 Intra-Frequency Mobility Management

3.1 Intra-Frequency Measurement

3.2 Triggering of an Intra-Frequency Handover 3.3 Handover Decision

3.4 Handover Execution

3.5 Signaling Procedures

3.5.1 Procedure of a Successful Handover

3.5.2 Procedure of RRC Connection Reestablishment After a Handover Failure

4 Inter-Frequency Mobility Management

4.1 Coverage-based Inter-Frequency Handover

4.1.1 Triggering and Stopping of Inter-Frequency Measurement

4.1.1.1 Event A2

4.1.1.2 Event A1

4.1.2 Inter-Frequency Measurement

4.1.3 Inter-Frequency Handover Triggering

4.1.3.1 Event A3

4.1.3.2 Event A4

4.1.3.3 Event A5

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4.1.4 Blind Handover

4.2 Service-based Inter-Frequency Handover




4.3 Distance-based Inter-Frequency Handover




4.4 UL-Quality-based Inter-Frequency Handover





4.5 Frequency-Priority-based Inter-Frequency Handover





4.6 Handover Decision

4.6.1 Target Decision

4.6.2 Admission Decision



5 Related Features

5.1 Coverage-based Intra-Frequency Handover




6 Network Impact


6.2 Coverage-based Inter-Frequency Handover 6.3 Service-based Inter-Frequency Handover


7 Engineering Guidelines


7.1.1 When to Use Coverage-based Intra-Frequency Handover

7.1.2 Required Information





















































































































7.1.3 Requirements

7.1.4 Data Preparation

7.1.5 Activation

7.1.6 Activation Observation

7.1.7 Deactivation

7.1.8 Performance Monitoring

7.1.9 Parameter Optimization

7.1.10 Troubleshooting


7.2.1 When to Use Coverage-based Inter-Frequency Handover


7.2.3 Requirements


7.2.5 Activation


7.2.7 Deactivation





7.3.1 When to Use Service-based Inter-Frequency Handover


7.3.3 Requirements


7.3.5 Activation


7.3.7 Deactivation





7.4.1 When to Use Distance-based Inter-Frequency Handover

7.4.2 Required Information 7.4.3 Requirements


7.4.5 Activation


7.4.7 Deactivation



























































































































7.5 UL-quality-based Inter-Frequency Handover

7.5.1 When to Use UL-quality-based Inter-Frequency Handover


7.5.3 Requirements


7.5.5 Activation


7.5.7 Deactivation





7.6.1 When to Use Frequency-Priority-based Inter-Frequency Handover


7.6.3 Requirements


7.6.5 Activation


7.6.7 Deactivation




8 Reference Documents

1 About This Document

1.1 Scope

This document describes intra-RAT mobility management in connected mode, including its technicalprinciples, related features, network impact, and engineering guidelines.

This document covers the following features:

LBFD-00201801 Coverage Based Intra-frequency Handover

LBFD-00201802 Coverage Based Inter-frequency Handover

LBFD-00201804 Distance Based Inter-frequency Handover

LBFD-00201805 Service Based Inter-frequency Handover

Any managed objects (MOs), parameters, alarms, or counters described herein correspond to thesoftware release delivered with this document. Any future updates will be described in the productdocumentation delivered with future software releases.



















































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This document applies only to LTE FDD. Any "LTE" in this document refers to LTE FDD, and "eNodeB"refers to LTE FDD eNodeB.

This document applies to the following types of eNodeBs.

eNodeB Type Model

Macro 3900 series eNodeB

Micro BTS3202E and BTS3203E

LampSite DBS3900

1.2 Intended Audience

This document is intended for personnel who:

Need to understand the features described herein

Work with Huawei products

1.3 Change History

This section provides information about the changes in different document versions. There are two typesof changes:

Feature change

Changes in features and parameters of a specified version as well as the affected entities.

Editorial change

Changes in wording or addition of information and any related parameters affected by editorialchanges. Editorial change does not specify the affected entities.

eRAN7.0 03 (2014-09-30)

This issue includes the following changes.

Change Type Change Description Parameter Change

Feature change None None

Editorial change Changed blind handling to blind handover. Fordetails, see descriptions about blind handover inthis document.

None

eRAN7.0 02 (2014-07-25)


Change Type Change Description Parameter Change Affected Entity

Feature change None None N/A

Editorial change Revised descriptions about inter-frequency measurement object

None N/A










selection in inter-frequencyhandovers. For details, see 4.1.2Inter-Frequency Measurement.

eRAN7.0 01 (2014-04-26)

This issue does not include any changes.

eRAN7.0 Draft B (2014-03-07)



Feature change None None N/A

Editorial change Added 1.4 Differences Between

eNodeB Types, which describesdifferences in feature supportbetween eNodeB types.

None N/A

eRAN7.0 Draft A (2014-01-20)

This is a draft for eRAN7.0.

1.4 Differences Between eNodeB Types

Features Support by Macro, Micro, and LampSite eNodeBs

Feature ID Feature Name Supported byMacro

eNodeBs

Supported byMicro eNodeBs

Supported byLampSite eNodeBs

LBFD-00201801 Coverage BasedIntra-frequencyHandover

Yes Yes Yes

LBFD-00201802 Coverage BasedInter-frequencyHandover

Yes Yes Yes

LBFD-00201804 Distance BasedInter-frequencyHandover

Yes No No


Yes Yes Yes

Function Implementation in Macro, Micro, and LampSite eNodeBs

Each feature or function is implemented in the same way on micro, macro, and LampSite sites.

2 Overview





















Based on the frequency of the target cell, intra-RAT mobility management can be classified into intra-frequency mobility management and inter-frequency mobility management.

2.1 Definition

Intra-Frequency Mobility Management

Intra-frequency mobility management is implemented by handovers between E-UTRAN cells using thesame frequency. A network may use the same frequency in different cells, and therefore the eNodeBneeds to support intra-frequency handovers within the network.

Inter-Frequency Mobility Management

Intra-frequency mobility management is implemented by handovers between E-UTRAN cells using thedifferent frequencies. A network may use different frequencies in different geographical areas, andtherefore the eNodeB needs to support inter-frequency handovers within the network.

2.2 Benefits

Intra-RAT mobility management in connected mode provides the following benefits:

Ensures the continuity of radio network coverage and provides uninterrupted communicationservices for UEs.

Provides means to transfer UEs and supports flexible networking to meet operators' servicesteering and load balancing requirements.

2.3 Architecture

For the network architecture for intra-RAT mobility management in connected mode, see Overview ofMobility Management in Connected Mode.

3 Intra-Frequency Mobility Management

Intra-frequency mobility management is implemented through coverage-based intra-frequency

handovers. This chapter describes the basic feature LBFD-00201801 Coverage Based Intra-frequencyHandover. For details about the engineering guidelines for this feature, see 7.1 Coverage-based Intra-Frequency Handover . The coverage-based intra-frequency handover is enabled or disabled by the switchIntraFreqCoverHoSwitch under the ENodeBAlgoSwitch.HoAlgoSwi tch parameter.

Blind handover is not supported during intra-frequency mobility management, and the coverage-basedintra-frequency handover process can be divided into the following phases:

1. Intra-frequency measurement

When a UE establishes a radio bearer, the eNodeB sends the UE the intra-frequencymeasurement configuration, based on which the UE performs measurements. Then, the UEgenerates a candidate cell list based on measurement results.

2. Triggering intra-frequency handovers

Intra-frequency handovers are triggered by event A3. For details, see 3.2 Triggering of anIntra-Frequency Handover .

3. Handover decision

In the handover decision phase, the eNodeB checks the cells in the candidate cell list anddetermines whether a handover needs to be initiated and, if so, to which cell the UE is to behanded over.

4. Handover execution



























In the handover execution phase, the eNodeB controls the procedure of UE handover to thetarget cell.

3.1 Intra-Frequency Measurement

If the switch for the coverage-based intra-frequency handover is turned on, the eNodeB sends the UE theintra-frequency measurement configuration in a Measurement Configuration message when the UE

establishes a radio bearer.

Based on the measurement configuration, the UE measures all cells on the associated frequency withinthe measurement scope.

After the UE enters the RRC connected mode or a handover is complete, the eNodeB checks whetherthe measurement configuration for the UE needs to be updated. If yes, the eNodeB delivers the entirelyor partially updated measurement configuration to the UE through an RRC Connection Reconfigurationmessage. If no, the eNodeB does not deliver updated measurement configuration. In this case, the UEuses the original measurement configuration.

The Measurement Configuration message used for intra-frequency measurements contains the basicinformation listed in Table 3-1. For details about the measurement report configuration, see 3.2 Triggeringof an Intra-Frequency Handover .

Table 3-1 Parameters in the measurement configuration

MeasurementConfiguration

ParameterName

Parameter ID Parameter Description

Measurementobjects

DownlinkEARFCN

Cell.DlEarfcn It is a cell-level parameter.

Frequencyoffset

Cell.QoffsetFreq It is a frequency-levelparameter.

Measurementbandwidth

CellResel.MeasBandWidth It is a cell-level parameter.

EUTRANRSRP filtercoefficient


HoMeasComm.EutranFi l terCoeffRSRP They are eNodeB-levelcommon parameters.

EUTRANRSRQ filtercoefficient

HoMeasComm.EutranFi l terCoeffRSRQ

3.2 Triggering of an Intra-Frequency Handover

Event A3 indicates that the signal quality in a neighboring cell is better than that in the serving cell. Whencoverage-based intra-frequency handover is enabled, the eNodeB sends measurement configurationsrelated to event A3 to the UE during UE radio bearer setup.

The entering and leaving conditions of event A3 are shown in Figure 3-1 and Figure 3-2. For details aboutevent A3, see section 5.5.4.4 "Event A3 (Neighbour becomes offset better than PCell)" in 3GPP TS36.331 V10.1.0.

Entering condition: Mn + Ofn + Ocn – Hys > Ms + Ofs + Ocs + Off

After receiving an event A3 from a UE, the eNodeB makes handover decision based on thereported candidate cell list.



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Leaving condition: Mn + Ofn + Ocn + Hys < Ms + Ofs + Ocs + Off

If the leaving condition of event A3 is met, the UE no longer reports event A3.

Figure 3-1 Event A3 triggering condition

Figure 3-2 Event A3 leaving condition

The variables in the preceding formulas are described in Table 3-2.

Assume that both Hys and Off are set to 2 dB. The eNodeB detects that the signal quality in the sourcecell always drops rapidly and the signal quality in the target cell always rises quickly in a handover.







To facilitate intra-frequency handovers, you can set Ocs to -1 dB for the serving cell and set Ocn to 1 dBfor the target cell.

Ofs and Ofn use the same value for an intra-frequency handover. Assume that they are set to 0 dB, thenthe entering condition of event A3 is as follows: Mn + 0 + 1 - 2 > Ms + 0 - 1 + 2. That is, event A3 can betriggered when the signal quality of the target cell is 2 dB higher than that of the serving cell.

Table 3-2 Parameters related to event A3

Variables in theFormula

Parameter Name


Ms - - Ms is the measurement result of theserving cell and Mn is the measurementresult of the neighboring cell. Themeasurement result type is specified bytheIntraRatHoComm.IntraFreqHoA3Trig Quan parameter.

Mn - -

Ofs/Ofn Frequency offset

Cell.QoffsetFreq This is a frequency-level parameter.

This parameter is contained in themeasurement configuration.

Ocs Cellspecificoffset

Cell.CellSpecif icOffset This is a cell-level parameter. Thisparameter is contained in themeasurement configuration.

Ocn Cellindividualoffset

EutranIntraFreqNCell.Cell IndividualO

ffset This is a cell-level parameter.

If the value is not 0, the parameteris contained in the measurementconfiguration.

If the value is 0, the parameter isnot contained in the measurementconfiguration and the default value0 is used for calculation.

Hys Intrafreqhandoverhysteresis

IntraFreqHoGroup.IntraFreqHoA3Hy st

This parameter is set for each QCI.

Off Intrafreqhandoveroffset

IntraFreqHoGroup.IntraFreqHoA3Off

set

Table 3-3 lists other parameters related to the reporting of event A3.

Table 3-3 Other parameters related to the reporting of event A3






ParameterName


Intrafreqhandover timeto trigger

IntraFreqHoGroup.IntraFreqHoA3TimeToTrig This parameter is set for each QCI.

Max report cellnumber

IntraRatHoComm.IntraRATHoMaxRprtCel l Cells included inthe measurementreport aresequenced basedon the value of Mn for triggering event A3.

These arecommoneNodeB-levelparametersused for intra-RAThandovers.

Measurementreport amount

IntraRatHoComm.In traRATHoRprtAmount This parameter isused to limit thenumber ofmeasurement

reports, reducingthe number ofhandover retries.

A3measurementtrigger quantity

IntraRatHoComm.IntraFreqHoA3TrigQuan This parameterspecifies the Mnand Ms type andtriggering quantityfor event A3.

A3measurementreport quantity

IntraRatHoComm.IntraFreqHoA3RprtQuan This parameterspecifies thereporting quantity

to be included inthe measurementreports after event A3 is triggered.

A3measurementreport interval

IntraRatHoComm.IntraFreqHoRprtInterval This parameterspecifies theinterval betweentwo event A3measurementreports from theUE. Setting thisparameter to a

proper valuereduces signalingtraffic on the airinterface.


In the handover decision phase, the eNodeB checks the cells in the candidate cell list and determineswhether a handover needs to be initiated and, if so, to which cell the UE is to be handed over.






The eNodeB first filters out following cells from the candidate cell list:

Blacklisted neighboring cells

Neighboring cells with a handover prohibition flag

Neighboring cells that have a different PLMN from the serving cell

These cells will not be filtered out if the inter-PLMN handover switch is turned on.InterPlmnHoSwitch under the ENodeBAlgoSwitch.HoAlgoSwi tch parameter controls theinter-PLMN handover switch.

Neighboring cells in the areas indicated by the IE Handover Restriction List in the INITIALCONTEXT SETUP REQUEST message sent from the MME

When a UE is performing VoIP services, cells that forbid VoIP handovers are also filtered.VoipHoControlSwitch under the ENodeBAlgoSwitch.HoAlgoSwi tch parameter specifies whether toenable this function.

When this switch is turned on, cells specified by EutranVoipHoBlkList are filtered when a UE isperforming VoIP services.

When this switch is turned off, cells specified by EutranVoipHoBlkList are not filtered when aUE is performing VoIP services.

The ENodeBAlgoSwitch.EutranVoipSupportSwi tch parameter indicates whether the VoIP services areallowed in the E-UTRAN cell.

When this switch is turned on, VoIP services are allowed in the E-UTRAN cell, which means thatthe establishment, handover in, admission, and reestablishment of VoIP services are allowed.

When this switch is turned off, VoIP services are not allowed in the E-UTRAN cell, which meansthat the establishment, handover in, admission, and reestablishment of VoIP services are notallowed.

Assume that eNodeB1 cells are neighboring cells of eNodeB2. It is recommended that eNodeB1 cells beadded to the EutranVoipHoBlkList parameter of eNodeB2 if eNodeB1 forbids VoIP service handover in.

Otherwise, the handover attempt fails.

The eNodeB then sends a handover request to the target cell at the top of the candidate cell list. If thehandover request fails, the eNodeB sends the handover request to the next target cell.

A cell with the best signal quality (as indicated in the measurement result) has the highest priority. If themeasurement result of an intra-eNodeB cell is the same as that of an inter-eNodeB cell, the eNodeBassigns the intra-eNodeB cell a higher priority to avoid signaling and data forwarding required in an inter-eNodeB handover.

If the eNodeB has tried all cells indicated in the measurement report but failed to perform a handover, theeNodeB waits for the next measurement report from the UE.


After making a handover decision, the eNodeB initiates a handover towards the best cell in the filteredcandidate cell list.

During an intra-frequency handover, the eNodeB sends handover requests and forwards data through theX2 or S1 interface adaptively.

If the handover succeeds, the target eNodeB (in an X2-based handover) or the MME (in an S1-based handover) sends a Release Resource message to the source eNodeB after dataforwarding is complete. The source eNodeB then release related resources.






If the handover fails, the UE performs a cell selection procedure and then initiates an RRCconnection reestablishment procedure towards the selected cell.

If the handover admission fails, the eNodeB initiates a handover attempt to the next best cell in thecandidate cell list. For details about the retry and penalty mechanism, see Overview of MobilityManagement in Connected Mode.


3.5.1 Procedure of a Successful Handover

This section describes the signaling procedure of a successful intra-MME inter-eNodeB handover, asshown in Figure 3-3.

Figure 3-3 Signaling procedure of a successful intra-MME inter-eNodeB handover

1. When the UE establishes a radio bearer, the source eNodeB sends the UE an RRCConnection Reconfiguration message that contains the measurement configuration, whichcontrols the measurements of the UE in RRC connected mode.

2. The UE sends measurement reports to the source eNodeB based on the measurement results.













3. The source eNodeB makes a handover decision based on the measurement reports.

4. After deciding that a handover is to be performed, the source eNodeB sends a HandoverRequest message to the target eNodeB, requesting the target eNodeB to prepare for thehandover.

5. The target eNodeB makes admission decisions. If resources can be granted by the target

eNodeB, the target eNodeB performs admission control depending on the QoS informationabout the Evolved Packet System (EPS) bearer.

6. The target eNodeB prepares layer 1 and layer 2 resources for the handover and then sends aHandover Request Acknowledge message to the source eNodeB.

7. The source eNodeB sends the UE an RRC Connection Reconfiguration message that containsthe MobilityControlInfo IE, indicating that the handover should start.

NOTE:

Data forwarding starts when the source eNodeB sends the UE an RRC ConnectionReconfiguration message that contains the MobilityControlInfo IE.

8. The UE performs a random access procedure towards the target eNodeB for uplink

synchronization with the target eNodeB.

9. After successfully accessing the target cell, the UE sends the target eNodeB an RRCConnection Reconfiguration Complete message, indicating that the handover procedure iscomplete. Subsequently, the target eNodeB can start sending data to the UE.

10. The downlink data path switching is performed.

11. The target eNodeB sends the source eNodeB a UE Context Release message to inform thesource eNodeB of a handover success and to trigger the resource release at the sourceeNodeB.

12. After receiving the UE Context Release message, the source eNodeB releases the radio andcontrol-plane resources associated with the UE context.

Intra-frequency mobility management is applicable to intra-eNodeB handovers, intra-MME inter-eNodeBhandovers, and inter-MME inter-eNodeB handovers. For either of the latter two handover types, thesignaling procedure varies depending on whether the X2 interface is available between the eNodeBs.

In the case of an intra-MME handover between eNodeBs where the X2 interface is unavailable,the signaling and the data forwarding between the two eNodeBs as shown in Figure 3-3 areimplemented over the S1 interface.

In the case of an inter-MME handover between eNodeBs where the X2 interface is unavailable,the signaling and the data forwarding between the two eNodeBs as shown in Figure 3-3 areimplemented over the S1 interface and Evolved Packet Core network (EPC), which is an indirectroute compared with the route over the X2 interface.

In the case of an inter-MME handover between eNodeBs where the X2 interface is available, the

signaling between the two eNodeBs as shown in Figure 3-3 is implemented through the S1interface and EPC, which is an indirect route compared with the route over the X2 interface. Inaddition, the data forwarding between them is implemented over the X2 interface.

3.5.2 Procedure of RRC Connection Reestablishment After a Handover Failure

After a handover fails, the UE performs a cell selection procedure and then initiates a procedure of RRCconnection reestablishment towards the selected cell. The RRC connection can be reestablishedsuccessfully only when the selected cell is a prepared cell.


















The RRC connection reestablishment procedure is different in successful RRC reestablishment and failedRRC reestablishment.

A successful reestablishment procedure, as shown in Figure 3-4, consists of the following steps:

1. The UE sends an RRC Connection Reestablishment Request message to the eNodeB towhich the prepared cell belongs, to request the reestablishment of the RRC connection.

2. The eNodeB responds with an RRC Connection Reestablishment message, indicating that ithas accepted the request.

3. The UE performs the RRC connection reestablishment and sends an RRC ConnectionReestablishment Complete message.

Figure 3-4 Successful RRC connection reestablishment procedure

If the RRC connection reestablishment fails, the UE enters the idle mode. A failedreestablishment procedure, as shown in Figure 3-5, consists of the following steps:

1. The UE sends an RRC Connection Reestablishment Request message to the eNodeB towhich the prepared cell belongs, to request the reestablishment of the RRC connection.

2. The eNodeB responds with an RRC Connection Reestablishment Reject message, indicatingthat it rejects the request.

Figure 3-5 Failed RRC connection reestablishment procedure

4 Inter-Frequency Mobility Management

Inter-frequency mobility management can be implemented in different manners. This section describesthe following features/functions:

LBFD-00201802 Coverage Based Inter-frequency Handover


LBFD-00201804 Distance Based Inter-frequency Handover

UL-quality-based inter-frequency handover

Frequency-priority-based inter-frequency handover














The triggering condition for each feature or function is different, and the mobility management can mainlybe divided into the following phases:

1. Target cell/frequency selection

For a measurement, the eNodeB generates a candidate cell list based on inter-RATmeasurement results.

For a blind handover, the eNodeB selects a blind handover target based on the blind handoverpriority or frequency priority of neighboring cells.

2. Handover decision

In the handover decision phase, the eNodeB checks the candidate cell list. Based on the checkresult, the eNodeB determines whether a handover needs to be initiated and, if so, to whichcell the UE is to be handed over.

3. Handover execution

In the handover execution phase, the eNodeB controls the procedure of UE handover to thetarget cell.

4.1 Coverage-based Inter-Frequency Handover This section describes the basic feature LBFD-00201802 Coverage Based Inter-frequency Handover. Fordetails about the engineering guidelines for this feature, see 7.2 Coverage-based Inter-FrequencyHandover . The coverage-based inter-frequency handover is enabled or disabled by the switchInterFreqCoverHoSwitch under the ENodeBAlgoSwitch.HoAlgoSwi tch parameter.

During a coverage-based inter-frequency handover, measurements or blind handover can be triggeredand stopped by different events, as shown in Table 4-1.

Table 4-1 Events for triggering/stopping measurements or blind handover during a coverage-based inter-frequency handover

Procedure Subprocedure Triggering Events Stopping Events

Measurement Inter-frequencymeasurement

Event A2 Event A1

Inter-frequencyhandover

Event A3, event A4, or event A5

-

Blindhandover

- Event A2 Event A1

The eNodeB delivers measurement configuration for event A2 for inter-frequency measurement or event A2 for blind handover as follows:

If the UE is in RRC-connected mode, the eNodeB delivers measurement configuration for both

event A2 for inter-frequency measurement and event A2 for blind handover.

If the signal quality in the serving cell is lower than the specified threshold, the UE reportsevent A2 for inter-frequency measurement. After receiving the report, the eNodeB deliversan inter-frequency measurement configuration.

If the signal quality in the serving cell further deteriorates and the eNodeB does notperform a handover for the UE, the UE reports event A2 for blind handover. After receivingthe report, the eNodeB considers that the serving cell can no longer provide services forthe UE and performs a blind handover.
















In the following scenarios, the eNodeB delivers measurement configuration for event A2 only forblind handover:

The UE does not support inter-frequency measurements.

The configured event A2 threshold for inter-frequency measurements is less than or equalto that for blind handover.


Inter-frequency measurements are triggered by event A2 and stopped by event A1.

During a coverage-based inter-frequency handover, the sequence that the measurement configuration forevents A1 and A2 is sent is controlled by the ReduceInvalidA1A2RptSigSwitch switch under theENodeBAlgoSwitch.HoSignal ingOptSwi tch parameter.

If the switch is turned on, the eNodeB sends measurement configuration for event A2 when theUE sets up an RRC connection, and sends measurement configuration for event A1 after itreceives an event A2 from the UE. This reduces the reporting of invalid event A1.

If the switch is turned off, the eNodeB sends measurement configuration for both event A2 andevent A1 when the UE sets up an RRC connection.

4.1.1.1 Event A2

Event A2 indicates that the signal quality of the serving cell is lower than a threshold.

Event A2 for Inter-Frequency Measurement

The entering and leaving conditions of event A2 are shown in Figure 4-1. For details about event A2, seesection 5.5.4.3 "Event A2 (Serving becomes worse than threshold)" in 3GPP TS 36.331 V10.1.0.

Entering condition: Ms + Hys < Thresh

If the entering condition is met, the UE reports an event A2. After receiving the event A2 report,the eNodeB delivers a measurement configuration to start inter-frequency measurement.

Leaving condition: Ms - Hys > Thresh














Figure 4-1 Entering and leaving conditions of event A2

The variables in the preceding formulas are described in Table 4-2 and Table 4-3. Thresholds related toevent A2 vary according to events that are used to trigger inter-frequency handovers.


Variables in theFormul

a

Parameter Name


Ms - - Ms is the measurement result of theserving cell. The measurement result typeis specified by theIntraRatHoComm.InterFreqHoA1A2Tri gQuan parameter.

Hys Interfreq A1A2hysteresis

InterFreqHoGroup.InterFreqHoA1A2Hyst


Table 4-3 Thresholds related to event A2 according to events that are used to trigger inter-frequencyhandovers











EventsThat

TriggerInter-

Frequency

Handover

Parameter

Nameof the

Threshold

Parameter ID of the Threshold Parameter Description

Event A3

A3basedInterfreq A2RSRPthreshold

InterFreqHoGroup.A3InterFreqHoA2ThdRsrp


If event A3 is used to trigger inter-frequency handover, the threshold forevent A2 can only be the RSRP threshold.

Events A4 and

A5

Interfreq A2

RSRPthreshold

InterFreqHoGroup.InterFreqHoA2T hdRSRP


The

IntraRatHoComm.InterFreqHoA1A2Trig Quan parameter determines whichthreshold is to be used.

IfIntraRatHoComm.InterFreqHoA1A2TrigQuan is set to BOTH, two A2events are reported, with one beingRSRP-based and the other RSRQ-based. When the entering conditionfor either of the A2 events is met, theUE reports the A2 event.

IfIntraRatHoComm.InterFreqHoA1A2TrigQuan is set to RSRP or RSRQ,the UE reports an A2 event onlywhen the entering condition for therelated A2 event is met.

Interfreq A2RSRQthreshold

InterFreqHoGroup.InterFreqHoA2T hdRSRQ

Table 4-4 lists other parameters related to the event A2 report.

Table 4-4 Other parameters related to the event A2 report

Parameter Name Parameter ID Parameter Description

Interfreq A1A2 timeto trigger

InterFreqHoGroup.InterFreqHoA1A2TimeToTrig This parameter is set foreach QCI.

InterFreq A1A2Measurement triggerquantity

IntraRatHoComm.InterFreqHoA1A2TrigQuan This is a commonparameter for intra-RAThandover and is set foreach eNodeB.

This parameter specifiesthe Ms type and triggering







quantity for events A1 and A2.

Event A2 for Target-based Measurement

Huawei eNodeBs allow different event A2 parameters to be set for target FDD and TDD frequencies sothat coverage-based handovers can be preferentially triggered for FDD or TDD frequencies.

The variables Ms and Hys for event A2 for target-based measurement are the same as those for event A2 for inter-frequency measurement. Table 4-5 lists the thresholds related to event A2 for target-basedmeasurement.

Table 4-5 Thresholds related to event A2 for target-based measurement

FrequencyType

Parameter ID of theThreshold Offset

Parameter ID of the Threshold Parameter

Description

FDD CnOperatorHoCfg.FddIfH oA2ThdRsrpOffset

InterFreqHoGroup.A3InterFreqHoA2ThdRsrp /InterFr eqHoGroup.InterFreqHoA2ThdRSRP

Thethreshold forevent A2 isthesum oftheRSRPthreshold.

Only

theRSRPthreshold forevent A2 isaccompaniedby anoffset,whiletheRSRQthreshold forevent A2 isnot.

TDD CnOperatorHoCfg.TddIfH oA2ThdRsrpOffset

The eNodeB delivers measurement configurations for event A2 for target-based measurement as follows:

If CnOperatorHoCfg.FddIfHoA2ThdRsrpOffset andCnOperatorHoCfg.TddIfHoA2ThdRsrpOffset are set to different values, the eNodeB delivers







two measurement configurations for events A2, with one corresponding to an FDD frequencyand the other corresponding to a TDD frequency. After a UE reports an event A2 related to afrequency, the eNodeB delivers the measurement configuration of the related frequency.

If CnOperatorHoCfg.FddIfHoA2ThdRsrpOffset andCnOperatorHoCfg.TddIfHoA2ThdRsrpOffset are set to the same value, the eNodeB deliversone measurement configuration for event A2, without distinguishing between the FDD and TDD

frequencies. After a UE reports an event A2, the eNodeB delivers two measurementconfigurations, one for the FDD frequency and the other for the TDD frequency.

Pay attention to the following points related to event A2 for target-based measurement:

If only either of the offset is set to -100, the inter-frequency measurement of an FDD or TDDfrequency is not triggered.

If both offset values are set to -100, the effect is the same as those set to 0. In this case, theeNodeB sends an inter-frequency event A2, with the threshold set to the event A2 thresholdvalue.

If the calculated RSRP threshold is lower than the protocol-specified minimum value, theprotocol-specified minimum value is used as the RSRP threshold.

If the calculated RSRP threshold is higher than the protocol-specified maximum value, theprotocol-specified maximum value is used as the RSRP threshold.

4.1.1.2 Event A1

Event A1 indicates that the signal quality of the serving cell is higher than a threshold.

The entering and leaving conditions of event A1 are shown in Figure 4-2. For details about event A1, seesection 5.5.4.2 "Event A1 (Serving becomes better than threshold)" in 3GPP TS 36.331 V10.1.0.

Entering condition: Ms - Hys > Thresh

When event A1 is triggered, the eNodeB receives an event A1 from the UE.

Leaving condition: Ms + Hys < Thresh

When the leaving condition of event A1 is met, the eNodeB no longer reports event A1.










Figure 4-2 Entering and leaving conditions of event A1

The variables in the formulas for event A1 are the same as those in the formulas for event A2. Thresholdsrelated to event A1 also vary according to events that are used to trigger inter-frequency handovers, asdescribed in Table 4-6.

Table 4-6 Thresholds related to event A1 according to events that are used to trigger inter-frequencyhandovers

EventsThat

TriggerInter-

Frequency

Handover

Parameter

Nameof the

Threshold


Event A3

A3basedInterfreq A1RSRPthreshold

InterFreqHoGroup.A3InterFreqHoA1ThdRsrp

This parameter is set for each QCI.If event A3 is used to trigger inter-frequency handover, the threshold forevent A1 can only be the RSRP threshold.







EventsThat

TriggerInter-

Frequency

Handover

Parameter

Nameof the

Threshold


Events A4 and A5

Interfreq A1RSRPthreshold

InterFreqHoGroup.InterFreqHoA1T hdRSRP


TheIntraRatHoComm.InterFreqHoA1A2Trig Quan parameter determines whichthreshold is to be used.

IfIntraRatHoComm.InterFreqHoA1A2TrigQuan is set to BOTH, two A1events are reported, with one beingRSRP-based and the other RSRQ-based. The eNodeB stops coverage-based inter-frequency measurementonly when both RSRP-based andRSRQ-based measurement resultsmeet the entering condition.

IfIntraRatHoComm.InterFreqHoA1A2TrigQuan is set to RSRP or RSRQ,the UE reports an A1 event onlywhen the entering condition for therelated A1 event is met.

Interfreq A1RSRQthreshol

d

InterFreqHoGroup.InterFreqHoA1T hdRSRQ

Other parameters related to the event A1 report are the same as those related to event A2 report. Fordetails, see Table 4-4.

You must set the thresholds related to event A1 to be higher than those related to event A2. If the RSRPthreshold offset for FDD or TDD frequencies are set, the thresholds related to event A1 must be greaterthan or equal to the sum of the thresholds related to event A2 and the offset.


The Measurement Configuration message used for inter-frequency measurements contains the basicinformation listed in Table 4-7. 4.1.3 Inter-Frequency Handover Triggering lists information contained inthe reporting configuration.

Table 4-7 Parameters in the measurement configuration


ParameterName


Measurementobjects

DownlinkEARFCN

EutranInterNFreq.DlEarfcn This is a cell-levelparameter.

If an inter-frequencyneighboring cell is amulti-band cell, theeNodeB calculates and



















ParameterName


delivers an EARFCNbased on the bandsupporting capability of

the UE.For details about therelationship between theband and EARFCN, seesection 5.7.3 "Carrierfrequency and EARFCN"in 3GPP TS 36.101V10.2.1.

For details about multi-band cells, see CellManagement .

Frequency

offset

EutranInterNFreq.QoffsetFreqConn This is a frequency-level

parameter.


EutranInterNFreq.MeasBandWidth This is a frequency-levelparameter.

Cellindividualoffset

EutranInterFreqNCell.Cell IndividualOffset This is a parameter for aneighboring cell.

Filtercoefficients


HoMeasComm.EutranFi l terCoeffRSRP This is an eNodeB-levelcommon parameter.

EUTRANRSRQ filtercoefficient

HoMeasComm.EutranFi l terCoeffRSRQ

Measurementgapconfiguration

GAPmeasurementpattern

HoMeasComm.GAPPatternType

The FixedMeasObjIDSwitch option of the CellAlgoSwitch.MultiFreqPriControlSwitch parameter specifies the frequency priority for UEs. The eNodeB selects the frequencies formeasurement in descending order of frequency priority till the number of selected frequenciesreaches the maximum. If all frequencies with the same priority are selected and the number offrequencies for measurement exceeds the maximum, the eNodeB randomly selects frequencies

with this priority till the number of selected priorities reaches the maximum.

When this option is deselected, the frequency priority is determined by theEutranInterNFreq.ConnFreqPriori ty parameter. A larger value indicates a higher priority.The eNodeB selects the frequencies for measurement in descending order of frequencypriority till the number of selected frequencies reaches the maximum.

When this option is selected, the frequency priority is determined by theEutranInterNFreq.MeasFreqPriori ty parameter. A larger value indicates a higher priority.The eNodeB sets measurement object IDs based on frequency priorities to control the



UE's actual measurement priorities. This ensures that the UE preferentially reports themeasurement reports on high-priority frequencies.

The eNodeB delivers information about a cell for measurement only if the cell individual offset(CIO) of the cell is not set to the default value (0 dB). The measurement priority of an inter-frequency neighboring cell is determined by the combination of the high bit and low bit specifiedby the EutranInterFreqNCell.CellMeasPriori ty and

EutranInterFreqNCell.Cell IndividualOffset parameters, respectively.

For details about the specifications of the number of frequencies and neighboring cells in ameasurement configuration message, see Overview of Mobility Management in ConnectedMode.


Coverage-based inter-frequency handovers can be triggered by event A3, A4, or A5. TheEutranInterNFreq.InterFreqHoEventType parameter specifies which event triggers coverage-basedinter-frequency handovers.

When receiving event A2 that triggers inter-frequency measurement, the eNodeB sends relatedinter-frequency handover event according to parameter configurations.

If carrier aggregation (CA) is enabled and the EutranInterNFreq.InterFreqHoEventType parameter is set to EventA4(EventA4), the eNodeB will send a measurement configuration forevent A5 to trigger an inter-frequency measurement when a CA UE reports an event A2 in theprimary serving cell (PCell). For details, see Carrier Aggregation.

4.1.3.1 Event A3

Event A3 triggers inter-frequency handovers the same way as it triggers intra-frequency handovers. Fordetails, see 3.2 Triggering of an Intra-Frequency Handover .

All parameters (other than Ofn and Off) for event A3 that triggers inter-frequency handovers are the sameas those for event A3 that triggers intra-frequency handovers. Table 4-8 lists the parameters related toevent A3.



Parameter Name


Ms - - Ms is the measurement result of theserving cell and Mn is the measurementresult of the neighboring cell. Themeasurement result type is specified bytheIntraRatHoComm.IntraFreqHoA3Trig Quan parameter.

Mn - -

Ofs Frequency offset

Cell.QoffsetFreq This is a frequency-level parameter.

This parameter is contained in themeasurement configuration.

Ofn Frequency offset

EutranInterNFreq.QoffsetFreqConn


















Parameter Name


Ocs Cellspecific

offset

Cell.CellSpecif icOffset This parameter is contained in themeasurement configuration.


EutranInterFreqNCell.Cell IndividualO

ffset If the value is not 0, the parameter

is contained in the measurementconfiguration.

If the value is 0, the parameter isnot contained in the measurementconfiguration and the default value0 is used for calculation.

Hys Intrafreqhandoverhysteresis

IntraFreqHoGroup.IntraFreqHoA3Hy st


Off Interfreq A3 offset

InterFreqHoGroup.InterFreqHoA3Off

set



ParameterName


Intrafreq

handover timeto trigger

IntraFreqHoGroup.IntraFreqHoA3TimeToTrig This parameter is set for each QCI.


IntraRatHoComm.IntraRATHoMaxRprtCel l The reported cellsare sequencedaccording to thevalue of Mn thattriggers event A3.

These arecommoneNodeB-levelparametersused for intra-RAThandovers.Measurement

report amountIntraRatHoComm.In traRATHoRprtAmount This parameter is

used to limit thenumber ofmeasurement

reports, reducingthe number ofhandover retries.

A3measurementtrigger quantity

IntraRatHoComm.IntraFreqHoA3TrigQuan This parameterspecifies the Mnand Ms type andtriggering quantityfor event A3.






ParameterName


A3measurementreport quantity

IntraRatHoComm.IntraFreqHoA3RprtQuan This parameterspecifies thereporting quantity

to be included inthe measurementreports after event A3 is triggered.

A3measurementreport interval

IntraRatHoComm.IntraFreqHoRprtInterval This parameterspecifies theinterval betweentwo event A3measurementreports from theUE. Setting thisparameter to a

proper valuereduces signalingtraffic on the airinterface.

4.1.3.2 Event A4

Event A4 indicates that the signal quality of a neighboring cell is higher than a threshold.

The entering and leaving conditions of event A4 are shown in Figure 4-3. For details about event A4, seesection 5.5.4.5 "Event A4 (Neighbour becomes better than threshold)" in 3GPP TS 36.331 V10.1.0.

Entering condition: Mn + Ofn + Ocn - Hys > Thresh

If the entering condition is met, the UE reports an event A4.

Leaving condition: Mn + Ofn + Ocn + Hys < Thresh











Figure 4-3 Entering condition of event A4

The variables in the preceding formulas are described in Table 4-10.


Variables inthe

Formula

Parameter Name


Mn - - Mn is the measurement result of theneighboring cell. The measurement resulttype is specified by theIntraRatHoComm.InterFreqHoA1A2Tri gQuan parameter.

Ofn Frequency offset

EutranInterNFreq.QoffsetFreqConn This is a frequency-level parameter.This parameter is contained in themeasurement configuration.

This parameter adjusts the UE topreferentially hands over to a specificfrequency. This parameter adjusts thehandover difficulty between cells ofdifferent frequencies.







Variables inthe

Formula

Parameter Name



EutranInterFreqNCell.Cell Individual Offset

This parameter is contained in theassociated measurement object in thedelivered measurement configuration.

Hys Interfreqhandoverhysteresis

InterFreqHoGroup.InterFreqHoA4Hy st


Table 4-11 lists the threshold parameters related to event A4.

Table 4-11 Threshold parameters related to event A4

ThresholdParameter

Threshold Value Parameter Description

CoverageBased InterfreqRSRPthreshold

When the triggering threshold is RSRP,the threshold value equalsInterFreqHoGroup.InterFreqHoA4Thd RSRP plusEutranInterNFreq.I fHoThdRsrpOffset .

The threshold parameter is set for each QCI.

The threshold offset parameter is set for eachinter-frequency neighboring frequency.

The threshold parameter is set for each QCI.

The threshold offset parameter is set for eachinter-frequency neighboring frequency.

TheIntraRatHoComm.InterFreqHoA1A2TrigQu

an parameter determines which triggeringthreshold is to be used.

WhenIntraRatHoComm.InterFreqHoA1A2Tr igQuan is set to BOTH, the eNodeBdelivers a measurement configurationrelated to event A4 according to thetriggering quantity of the reported event A2.

WhenIntraRatHoComm.InterFreqHoA1A2Tr igQuan is set to RSRP or RSRQ, theeNodeB delivers a measurementconfiguration related to event A4 for

which the triggering quantity is RSRP orRSRQ, respectively.

TheIntraRatHoComm.InterFreqHoA4RprtQuan parameter determines the reporting quantityto be included in the measurement reportsafter event A4 is triggered.

WhenIntraRatHoComm.InterFreqHoA4Rprt

CoverageBased InterfrqRSRQthreshold

When the triggering threshold is RSRQ,the threshold value equalsInterFreqHoGroup.InterFreqHoA4Thd RSRQ .






ThresholdParameter

Threshold Value Parameter Description

Quan is set to BOTH, two A4 eventsare reported, with one being RSRP-based and the other RSRQ-based. An

inter-frequency handover is triggeredonly when both measurement quantitiesmeet the condition that the sum of theMn, Ofn, Ocn, and Hys values is greaterthan or equal to the threshold value.

WhenIntraRatHoComm.InterFreqHoA4Rprt Quan is set toSAME_AS_TRIG_QUAN(Same as TrigQuan), coverage-based measurementreport type for event A4 is the same asthe measurement triggering quantity.



ParameterName


InterfreqHandOverTime to Trigger

InterFreqHoGroup.InterFreqHoA4TimeToTrig This parameter is set for each QCI.


IntraRatHoComm.IntraRATHoMaxRprtCel l The reported cellsare sequenced

according to thevalue of Mn thattriggers event A3.

This is acommon

parameter forintra-RAThandover andis set for eacheNodeB.Measurement

report amountIntraRatHoComm.In traRATHoRprtAmount This parameter

specifies thenumber of eventsto be reported.Setting thisparameter to aproper valuereduces thenumber of

handover retries.

InterFreq A1A2Measurementtrigger quantity

IntraRatHoComm.InterFreqHoA1A2TrigQuan This parameterspecifies the Mntype.

Measurement A4 reportquantity

IntraRatHoComm.InterFreqHoA4RprtQuan This parameterspecifies thereporting quantity






ParameterName


to be included inthe measurementreports after event

A4 is triggered.

Interfreqmeasurementreport interval

IntraRatHoComm.InterFreqHoRprtInterval This parameterspecifies theinterval at whichperiodicalmeasurementreports are sentafter event A4 istriggered.

4.1.3.3 Event A5

Event A5 indicates that the signal quality of the serving cell is lower than threshold 1 (Thresh1) and thesignal quality of a neighboring cell is higher than threshold 2 (Thresh 2).

The entering and leaving conditions of event A5 are shown in Figure 4-4. For details about event A5, seesection 5.5.4.6 "Event A5 (PCell becomes worse than threshold1 and neighbour becomes better thanthreshold2)" in 3GPP TS 36.331 V10.1.0.

Entering condition: Ms + Hys < Thresh1 and Mn + Ofn + Ocn - Hys > Thresh2

If the entering condition is met, the UE reports an event A5. After receiving the event A5 report,the eNodeB delivers a measurement configuration to start inter-frequency handover.

Leaving condition: Ms - Hys > Thresh1 or Mn + Ofn + Ocn + Hys < Thresh2











Figure 4-4 Entering condition of event A5

All parameters (other than thresholds) for event A5 are the same as those for event A4. For details, seeTable 4-10 and Table 4-12.

For event A5 that triggers inter-frequency handover, Thresh1 is the same as the event A2 threshold forcoverage-based inter-frequency handover and Thresh2 is the same as the event A4 threshold forcoverage-based inter-frequency handover. Table 4-13 describes threshold parameters.

Table 4-13 Thresh1 for event A5

Threshold

Parameter


Interfreq A2 RSRPthreshold

InterFreqHoGroup.InterFreqHoA2ThdRS RP


TheIntraRatHoComm.InterFreqHoA1A2TrigQu

an parameter determines which threshold isto be used.Interfreq

A2 RSRQthreshold

InterFreqHoGroup.InterFreqHoA2ThdRS RQ

Table 4-14 Thresh2 for event A5














Threshold

Parameter

Parameter ID Threshold Value Parameter Description

Coverage

BasedInterfreqRSRPthreshold

InterFreqHoGroup.InterFre

qHoA4ThdRSRP

When the triggering threshold

is RSRP, Thresh2 equalsInterFreqHoGroup.InterFreq HoA4ThdRSRP plusEutranInterNFreq.I fHoThdR srpOffset .

The threshold parameter is

set for each QCI.The threshold offsetparameter is set for eachinter-frequency neighboringfrequency.

TheIntraRatHoComm.InterFre qHoA4RprtQuan parameterdetermines which thresholdis to be used.

CoverageBasedInterfrqRSRQthreshold

InterFreqHoGroup.InterFre qHoA4ThdRSRQ

When the triggering thresholdis RSRQ, Thresh2 equalsInterFreqHoGroup.InterFreq HoA4ThdRSRQ .

4.1.4 Blind Handover Triggering and Stopping of Blind Handover

The eNodeB can deliver a measurement configuration related to event A2 for blind handover if the signalquality of the serving cell deteriorates to a specified level but the UE has not yet been handed over. TheeNodeB also delivers the measurement configuration related to event A1 to stop blind handover when thesignal quality in the serving cell does not further deteriorate.

The eNodeB records the reports of event A2 for blind handover during handover preparation andhandles them if the handover preparation fails.

If the eNodeB receives a report of event A1 used to stop a blind handover from the UE beforeblind handover is completed, the eNodeB stops performing blind handover.

If the EmcInterFreqBlindHoSwitch option of the ENodeBAlgoSwitch.HoAlgoSwi tch parameter isselected, the eNodeB performs a blind handover procedure for coverage-based inter-frequencyhandover. The eNodeB selects an inter-frequency target cell when the UE sends a report of event A2 forblind handover.

Table 4-15 lists parameters related to events A1 and A2 for blind handover.

Table 4-15 Parameters related to events A1 and A2

Variables inthe

Formula

Parameter Name


Ms - - Ms is the measurement result of theserving cell. The measurement result typeis specified by theInterRatHoComm.InterRatHoA1A2Trig Quan parameter.

Hys InterRAT A1A2

InterRatHoCommGroup.InterRatHoA1A2Hyst










Variables inthe

Formula

Parameter Name


hysteresis

Thresh BlindHO A1A2RSRPtriggerthreshold

CellHoParaCfg.Bl indHoA1A2ThdRsr

p This is a cell-level parameter.

TheInterRatHoComm.InterRatHoA1A2Trig Quan parameter determines whichthreshold is to be used.

IfInterRatHoComm.InterRatHoA1A2 TrigQuan is set to BOTH, two A2events are reported, with one beingRSRP-based and the other RSRQ-

based. When the entering conditionfor either of the A2 events is met,the UE reports the A2 event.

IfInterRatHoComm.InterRatHoA1A2 TrigQuan is set to RSRP or RSRQ,the UE reports an A2 event onlywhen the entering condition for therelated A2 event is met.

BlindHO A1A2RSRQ

triggerthreshold

CellHoParaCfg.Bl indHoA1A2ThdRsr

q

Table 4-16 lists other parameters related to the event A1/A2 report for blind handover.

Table 4-16 Other parameters related to the event A1/A2 report


InterRAT A1A2time to trigger

InterRatHoCommGroup.InterRatHoA1A2TimeToTrig This parameter is set foreach QCI.

InterRat A1A2measurementtrigger quantity

InterRatHoComm.InterRatHoA1A2TrigQuan This is a commonparameter for inter-RAThandover and is set foreach eNodeB.

This parameter specifiesthe Ms type andtriggering quantity for

events A1 and A2.

Event A2 for blind handover can be used to trigger both coverage-based inter-frequency blind redirectionand inter-RAT blind handover. Coverage-based inter-frequency blind redirection and inter-RAT blindhandover share the same thresholds related to event A2. The working principles for event A2 forcoverage-based inter-frequency blind redirection and inter-RAT blind handover are similar. For detailsabout event A2 for inter-RAT blind handover, see Inter-RAT Mobility Management in Connected Mode.For details about event A2 for inter-RAT blind handover, see Inter-RAT Mobility Management inConnected Mode.






Target Selection

Figure 4-5 shows the target selection process for blind handover. The related parameters are describedas follows:

In coverage-based inter-frequency blind handover, target cells must be the neighboring cellswhose EutranInterFreqNCell.Bl indHoPr ior i ty is set to a value within the range of 1 to 16. A

larger value indicates a higher priority.

The eNodeB preferentially selects a frequency with the highest priority for the redirection. Thefrequency priority is specified by the EutranInterNFreq.ConnFreqPriori ty parameter. A largervalue indicates a higher priority. When this parameter is set to 0, the frequency is not selectedfor redirection.

Figure 4-5 Target selection process for blind handover

For a coverage-based blind handover, E-UTRAN TDD and E-UTRAN FDD are considered as twoindependent systems, and the CnOperatorHoCfg.FirstRatPri and CnOperatorHoCfg.SecondRatPri parameters specify the priorities of E-UTRAN TDD and E-UTRAN FDD.

If the CnOperatorHoCfg.FirstRatPri parameter is set to EUTRAN, E-UTRAN TDD and E-UTRAN FDD are not prioritized.

If the CnOperatorHoCfg.SecondRatPri parameter is set to NULL, blind handover are performedonly to frequencies of the network specified the CnOperatorHoCfg.FirstRatPri parameter.


This section describes the basic feature LBFD-00201805 Service Based Inter-frequency Handover. Fordetails about the engineering guidelines for this feature, see 7.3 Service-based Inter-FrequencyHandover . Service-based inter-frequency handover can be enabled by theServiceBasedInterFreqHoSwitch switch under the ENodeBAlgoSwitch.HoAlgoSwi tch parameter.

Service-based inter-frequency handovers are applicable to two neighboring E-UTRAN frequencies thatcover the same area. Based on the QCIs of the services that are running on a UE, the eNodeB can divertthe UE to an appropriate co-coverage E-UTRAN frequency by means of a service-based inter-frequencyhandover to implement service steering.

Table 4-17 describes events for triggering/stopping measurement and handover during a service-basedinter-frequency handover. Blind handover is not applied to service-based inter-frequency handover.


















Table 4-17 Events for triggering/stopping measurement and handover during a service-based inter-frequency handover

Procedure Triggering Events Stopping Events

Inter-frequency

measurement

UE service with the highest-priority

QCI is allowed to be handed over toa frequency on a different band.

The UE service is terminated.


Event A4 -


To implement service-based inter-frequency handovers, operators need to configure service-based inter-frequency handover policies. Since the services of each operator are classified by QCIs, each QCI can beassociated with a service-based inter-frequency handover policy so that the frequency specified by thepolicy preferentially carries the services with this QCI. There must be at least one neighboring cellworking on this frequency. The eNodeB triggers a service-based inter-frequency handover for a UE

based on the highest-priority QCI of the services running on the UE.

1. Set the service-based inter-frequency handover policy (specified by theServiceIfHoCfgGroup.InterFreqHoState parameter) for a frequency (specified by theServiceIfDlEarfcnGrp.DlEarfcn parameter) to PERMIT_HO.

2. Associate a QCI (specified by CnOperatorStandardQci.Qci or ExtendedQci.ExtendedQci )with the service-based inter-frequency handover policy.

3. If the UE performs services with this QCI and the QCI is with the highest priority, the eNodeBdelivers a measurement configuration for event A4. Then the UE measures the frequency(specified by the ServiceIfDlEarfcnGrp.DlEarfcn parameter).

4. The UE stops service-based inter-frequency measurement when the UE stops services withthis QCI.

The QCI priority is specified by the CellStandardQci.QciPriori tyForHo parameter. A smaller valueindicates a higher priority.

If the configurations for QCI priorities are the same, handover parameter selection is based on the QCIpriority specified in 3GPP. For details, see section 6.1.7 "Standardized QoS characteristics" in 3GPP TS23.203 V10.3.0.


Before delivering the measurement configuration related to event A4, the eNodeB checks whether themeasurement gap has been activated. If the measurement gap has been activated and includes othermeasurement gap, the eNodeB does not perform any handling. Otherwise, the eNodeB activates themeasurement gap.

If a UE has performed gap-assisted measurements for a service-based inter-frequency handover for aperiod of time (internally set to 3s) but fails to trigger such a handover, the eNodeB will stop the service-based inter-frequency measurements.

Parameters in the measurement configuration for service-based inter-frequency measurement are thesame as those for coverage-based inter-RAT measurement. For details, see 4.1.2 Inter-FrequencyMeasurement.



















Service-based inter-frequency handovers can be triggered by event A4. Working principles of event A4for triggering service-based inter-frequency handovers are the same as those of event A4 for triggeringcoverage-based inter-frequency handovers. For details, see 4.1.3.2 Event A4.

All parameters (other than thresholds) for event A4 that triggers service-based inter-frequency handoversare the same as those for event A4 that triggers coverage-based inter-frequency handovers. Table 4-18 lists the thresholds related to event A4.

Table 4-18 Thresholds related to event A4 that triggers service-based inter-frequency handovers

Parameter Name


LoadBasedInterfreqRSRPthreshold

InterFreqHoGroup.InterFreqLoadBasedHoA4 ThdRSRP


TheIntraRatHoComm.InterFreqHoA4TrigQ

uan parameter determines whichthreshold is to be used.

IfIntraRatHoComm.InterFreqHoA4T

rigQuan is set to BOTH, two A4events are delivered, with one beingRSRP-based and the other RSRQ-based. When the entering conditionfor either of the A4 events is met,the UE reports the A4 event. Aninter-frequency handover istriggered only when the triggeringconditions for both of the A4 eventsare met.

WhenIntraRatHoComm.InterFreqHoA4T rigQuan is set to RSRP or RSRQ,

the eNodeB delivers a measurementconfiguration related to event A4 forwhich the triggering quantity isRSRP or RSRQ, respectively.

TheIntraRatHoComm.InterFreqHoA4RprtQ

uan parameter determines the reportingquantity to be included in themeasurement reports after event A4 istriggered.

WhenIntraRatHoComm.InterFreqHoA4R prtQuan is set to BOTH, two A4

events are reported, with one beingRSRP-based and the other RSRQ-based.

WhenIntraRatHoComm.InterFreqHoA4R prtQuan is set toSAME_AS_TRIG_QUAN(Same asTrig Quan), service-basedmeasurement report type for event

LoadBasedInterfreqRSRQthreshold

InterFreqHoGroup.InterFreqLoadBasedHoA4 ThdRSRQ











Parameter Name


A4 is the same as the measurementtriggering quantity.

The event A4 triggering quantity for service-based inter-frequency handovers is determined by theIntraRatHoComm.InterFreqHoA4TrigQuan parameter. Other parameters related to the event A4 reportfor service-based inter-frequency measurement are the same as the parameters related to the event A4report for coverage-based inter-frequency measurement. For details, see 4.1.3.2 Event A4.

When a service-based inter-frequency handover is triggered, the eNodeB checks the handover historyinformation of the UE. If the target frequency for the handover is the same as the frequency of the cellwhere the UE is previously located, the handover is not performed to prevent ping-pong handovers.


This section describes the basic feature LBFD-00201804 Distance Based Inter-frequency Handover. Fordetails about the engineering guidelines for this feature, see 7.4 Distance-based Inter-FrequencyHandover . The CellAlgoSwitch.DistBasedHoSwi tch parameter specifies whether to enable distance-

based inter-frequency handover.

Distance-based inter-frequency handover can be triggered only when theDistBasedHO.DistBasedMeasObjType parameter is set to EUTRAN.

Distance-based inter-frequency handover applies in high- and low-band hybrid networks where cells onthe low band cover a larger area than cells on the high band and overshoot coverage occurs on the highband while neighbor relations are missing on the low band.

As shown in Figure 4-6, the 1800 MHz band F1 is used to cover the urban area and the 800 MHz bandF2 is used to cover the suburban area. If there are only a few buildings along the border between theurban area and the suburban area, the RF signals from an F1 cell may be able to travel a long distance(typically three times the distance between sites), causing overshoot coverage to an F2 cell. The trianglearea in the UE moving direction indicates overshoot coverage.

As there are restrictions on number of cells between two neighboring cells, Cell D cannot be configuredas a neighboring cell of Cell A. However, because of overshoot coverage of Cell A, the UE cannot triggercoverage-based inter-frequency handover in Cell B and Cell C. When the UE reaches Cell D and movesout of the overshoot coverage area, service drops will occur because of the missing neighbor relationship.The deviation in the estimated distance between the UE and eNodeB is about 100 to 150 meters.

NOTE:

Obtaining the distance between the UE and the eNodeB is dependent on the uplink timing advance (TA).The eNodeB measures the TA of a UE and sends the TA value to the UE through a timing advancecommand. The TA accuracy is 16 Ts.

Ts is the minimum time unit at the physical layer in LTE. The formula for calculating Ts is as follows: Ts =1/(15000 x 2048)s = 32.55 ns.

The formula for calculating the distance in a distance-based inter-frequency handover is as follows: 16Ts/2 x Radio transmitting speed. That is, 16 x 32.55 ns /2 x 3 x 10^8 m/s = 78.12 m.




















Figure 4-6 Distance-based inter-frequency handover

Table 4-19 lists the triggering and stopping conditions for triggering/stopping measurement and handoverduring a distance-based inter-frequency handover. Blind handover is not applied to distance-based inter-frequency handover.

Table 4-19 Events for triggering/stopping measurement and handover during a distance-based inter-frequency handover

Procedure Triggering Events Stopping Events

Inter-frequencymeasurement

Distance between the UE andeNodeB exceeds the specifiedthreshold.

Distance between the UE and eNodeBfalls below the specified threshold.


Event A4 -


Distance-based inter-frequency handovers are triggered by the eNodeB based on the distance betweenthe eNodeB and the UE.

The eNodeB keeps monitoring the distance to all UEs. Upon detecting that the measured distance to aUE exceeds the threshold specified by the DistBasedHO.DistBasedHOThd parameter for 10 seconds(which is a fixed value), the eNodeB delivers the measurement configuration for event A4 to the UE.

While the measurements for a distance-based inter-frequency handover are being taken, if the eNodeBdetects that the reported TA value does not meet DistBasedHO.DistBasedHOThd for 10 seconds, themeasurements are immediately stopped.


Before delivering the measurement configuration related to event A4, the eNodeB checks whether themeasurement gap has been activated. If the measurement gap has been activated and includes other

measurement gap, the eNodeB does not perform any handling. Otherwise, the eNodeB activates themeasurement gap.

If a UE has performed gap-assisted measurements for a distance-based inter-frequency handover for aperiod of time (internally set to 3s) but fails to trigger such a handover, the eNodeB releases themeasurement gaps for distance-based inter-frequency handovers to stop the measurements.

Parameters in the measurement configuration for distance-based inter-frequency measurement are thesame as those for coverage-based inter-frequency measurement. For details, see 4.1.2 Inter-FrequencyMeasurement.



















Distance-based inter-frequency handovers can be triggered by event A4. Working principles of event A4for triggering distance-based inter-frequency handovers are the same as those of event A4 for triggeringcoverage-based inter-frequency handovers. For details, see 4.1.3.2 Event A4.

All parameters (other than thresholds) for event A4 that triggers distance-based inter-frequency

handovers are the same as those for event A4 that triggers coverage-based inter-frequency handovers.Table 4-20 lists the thresholds related to event A4.

Table 4-20 Thresholds related to event A4 that triggers distance-based inter-frequency handovers

ParameterName


CoverageBased InterfreqRSRPthreshold

InterFreqHoGroup.InterFreqHoA4Thd RSRP


TheIntraRatHoComm.InterFreqHoA4TrigQua

n parameter determines which threshold isto be used.

IfIntraRatHoComm.InterFreqHoA4Trig Quan is set to BOTH, two A4 eventsare delivered, with one being RSRP-based and the other RSRQ-based.When the entering condition for eitherof the A4 events is met, the UE reportsthe A4 event. An inter-frequencyhandover is triggered only when thetriggering conditions for both of the A4events are met.

WhenIntraRatHoComm.InterFreqHoA4Trig

Quan is set to RSRP or RSRQ, theeNodeB delivers a measurementconfiguration related to event A4 forwhich the triggering quantity is RSRPor RSRQ, respectively.

TheIntraRatHoComm.InterFreqHoA4RprtQua

n parameter determines the reportingquantity to be included in the measurementreports after event A4 is triggered.

WhenIntraRatHoComm.InterFreqHoA4Rpr tQuan is set to BOTH, two A4 events

are reported, with one being RSRP-based and the other RSRQ-based.

WhenIntraRatHoComm.InterFreqHoA4Rpr tQuan is set toSAME_AS_TRIG_QUAN(Same asTrig Quan), distance-basedmeasurement report type for event A4

CoverageBased InterfreqRSRQthreshold

InterFreqHoGroup.InterFreqHoA4Thd RSRQ













ParameterName


is the same as the measurementtriggering quantity.

The event A4 triggering quantity for distance-based inter-frequency handovers is determined by theIntraRatHoComm.InterFreqHoA4TrigQuan parameters. Other parameters related to the event A4report for distance-based inter-frequency measurement are the same as the parameters related to theevent A4 report for coverage-based inter-frequency measurement. For details, see 4.1.3.2 Event A4.

4.4 UL-Quality-based Inter-Frequency Handover

This section describes UL-quality-based inter-frequency handover. For details about the engineeringguidelines for this feature, see 7.5 UL-quality-based Inter-Frequency Handover . UL-quality-based inter-frequency handover can be enabled by the UlQualityInterFreqHoSwitch switch under theENodeBAlgoSwitch.HoAlgoSwi tch parameter.

A UL-quality-based inter-frequency handover prevents service drops caused by deteriorated UL quality.

Table 4-21 describes events for triggering and stopping measurement and blind handover during an UL-quality-based inter-frequency handover.

Table 4-21 Events for triggering/stopping measurement and blind handover during an UL-quality-basedinter-frequency handover



UL quality becomes worse. UL quality becomes better.


Event A4 -

BlindHandover

- UL quality becomes furtherworse, but the eNodeB doesnot receive any event A4reports.

-


UL-quality-based inter-frequency handovers are triggered based on the UL signal quality. When the ULsignal quality is unsatisfactory, call drops may occur if handovers are not performed in time. The eNodeBchecks the uplink signal quality. If the eNodeB finds that the uplink signal quality is poor, it delivers themeasurement configuration for event A4.

When a UE detects that the uplink quality becomes better, the eNodeB stops UL-quality-based inter-

frequency measurements.


Before delivering the measurement configuration related to event A4, the eNodeB checks whether themeasurement gap has been activated. If the measurement gap has been activated and includes othermeasurement gap, the eNodeB does not perform any handling. Otherwise, the eNodeB activates themeasurement gap.























If a UE has performed gap-assisted measurements for a UL-quality-based inter-frequency handover for aperiod of time (internally set to 3s) but fails to trigger such a handover, the eNodeB releases themeasurement gaps for UL-quality-based inter-frequency handovers to stop the measurements.

Parameters in the measurement configuration for UL-quality-based inter-frequency measurement are thesame as those for coverage-based inter-frequency measurement. For details, see 4.1.2 Inter-FrequencyMeasurement.


UL-quality-based inter-frequency handovers can be triggered by event A4. Working principles of event A4for triggering UL-quality-based inter-frequency handovers are the same as those of event A4 for triggeringcoverage-based inter-frequency handovers. For details, see 4.1.3.2 Event A4.

Parameters related to event A4 that triggers UL-quality-based inter-frequency handovers are the same asthose related to event A4 that triggers distance-based inter-frequency handovers. For details, see 4.3.3Inter-Frequency Handover Triggering.


Triggering of Blind Handover

If the UL quality for the UE further deteriorates but the eNodeB does not receive an event A4measurement report, the eNodeB considers that service drops may occur due to the poor UL quality. Inthis situation, the eNodeB performs blind handover for the UE.

Target Selection

The target selection process of UL-quality-based inter-frequency blind handover is the same as that ofcoverage-based inter-frequency blind handover. For details, see 4.1.4 Blind Handover .


This section describes frequency-priority-based inter-frequency handover. For details about theengineering guidelines for this function, see 7.6 Frequency-Priority-based Inter-Frequency Handover .

Frequency-priority-based inter-frequency handover can be enabled by the FreqPriorIFHOSwitch switchunder the CellAlgoSwitch.FreqPriori tyHoSwitch parameter.

When cells on a low band (for example, 900 MHz) and a high band (for example, 1800 MHz) have thesame coverage, a frequency-priority-based inter-frequency handover can be performed to preferentiallycarry services in the high band while sparing the low band for continuous coverage. Figure 4-7 showsfrequency-priority-based inter-frequency handover.








































Figure 4-7 Frequency-Priority-based Inter-Frequency Handover

Table 4-22 lists the triggering and stopping conditions for triggering/stopping measurement and handover

during a distance-based inter-frequency handover.

Table 4-22 Events for triggering/stopping measurement and blind handover during a frequency-priority-based inter-frequency handover



Event A1 Event A2


Event A4 -

Blindhandover - Event A1 Event A2

Events A1 and A2 are respectively used for triggering and stopping measurement and blind handover.When the eNodeB receives an event A1 report, blind handover or inter-frequency measurement istriggered as follows:

Blind handover is triggered if it has been enabled by turning on the FreqPriorIFBlindHOSwitch switch under the CellAlgoSwitch.FreqPriori tyHoSwitch .

If blind handover is not enabled, the eNodeB delivers a measurement configuration for event A4to trigger inter-frequency measurement.


During frequency-priority-based inter-frequency measurement, the sequence that the measurementconfiguration of events A1 and A2 for triggering and stopping inter-frequency measurements is sent iscontrolled by the ReduceInvalidA1A2EventRptSigSwitch switch under theENodeBAlgoSwitch.HoSignal ingOptSwi tch parameter.

If the switch is turned on, the eNodeB sends measurement configuration for event A1 when theUE sets up an RRC connection, and sends measurement configuration for event A2 after itreceives an event A1 from the UE. This reduces the reporting of invalid event A2.









If the switch is turned off, the eNodeB sends measurement configuration for both event A2 andevent A1 when the UE sets up an RRC connection.

Triggering of Inter-Frequency Measurement

When frequency-priority-based inter-frequency handover is enabled, the eNodeB delivers event A1 forfrequency-priority-based inter-frequency measurement.

Working principles of event A1 for triggering frequency-priority-based inter-frequency measurement is thesame as those of event A1 for triggering coverage-based inter-frequency measurement. Parameters(other than those for thresholds and triggering quantity) in the measurement configuration for frequency-priority-based inter-frequency measurement are the same as those for coverage-based inter-frequencymeasurement. For details, see 4.1.1.2 Event A1. Parameters for thresholds and triggering quantity arelisted in Table 4-23.

Table 4-23 Parameters for event A1 for triggering frequency-priority-based inter-frequency measurement

ParameterName of

theThreshold


FreqPriorityBasedInterfreq A1 RSRPthreshold

InterFreqHoGroup.FreqPri InterFreqHoA1ThdRsrp


TheIntraRatHoComm.FreqPri InterFreqHoA1Tri gQuan parameter determines which thresholdis to be used.

IfIntraRatHoComm.FreqPri InterFreqHo A1TrigQuan is set to BOTH, two A1events are reported, with one beingRSRP-based and the other RSRQ-based. When the entering condition for

either of the A1 events is met, the UEreports the A1 event.

IfIntraRatHoComm.FreqPri InterFreqHo A1TrigQuan is set to RSRP or RSRQ,the UE reports an A1 event only whenthe entering condition for the related A1event is met.

FreqPriorityBasedInterfreq A1 RSRQ

threshold

InterFreqHoGroup.FreqPri InterFreqHoA1ThdRsrq

A1A2Measurement triggerquantity of

FreqPriority

IntraRatHoComm.FreqPri InterFreqHoA1TrigQuan

This is a common eNodeB-level parameterused for intra-RAT handovers.

This parameter specifies the Ms type andtriggering quantity for events A1 and A2.

Stopping of Inter-Frequency Measurement

Inter-frequency measurement stops when the eNodeB receives an event A2 report for frequency-priority-based inter-frequency measurement.

Working principles of event A2 for stopping frequency-priority-based inter-frequency measurement is thesame as those of event A2 for stopping coverage-based inter-frequency measurement. Parameters (otherthan those for thresholds and triggering quantity) in the measurement configuration for frequency-priority-











based inter-frequency measurement are the same as those for coverage-based inter-frequencymeasurement. For details, see 4.1.1.1 Event A2. Parameters for thresholds and triggering quantity arelisted in Table 4-24.

Table 4-24 Parameters for event A2 for stopping frequency-priority-based inter-frequency measurement

Parameter

Name ofthe

Threshold


FreqPriorityBasedInterfreq A2 RSRPthreshold

InterFreqHoGroup.FreqPri InterFreqHoA2ThdRsrp


TheIntraRatHoComm.FreqPri InterFreqHoA1Tri gQuan parameter determines which thresholdis to be used.

IfIntraRatHoComm.FreqPri InterFreqHo A1TrigQuan is set to BOTH, two A2

events are reported, with one beingRSRP-based and the other RSRQ-based. When the entering condition foreither of the A2 events is met, the UEreports the A2 event.

IfIntraRatHoComm.FreqPri InterFreqHo A1TrigQuan is set to RSRP or RSRQ,the UE reports an A2 event only whenthe entering condition for the related A2event is met.

FreqPriority

BasedInterfreq A2 RSRQthreshold

InterFreqHoGroup.FreqPri InterFreqHoA2ThdRsrq

A1A2

Measurement triggerquantity ofFreqPriority

IntraRatHoComm.FreqPri InterFreqHoA

1TrigQuan

This is a common eNodeB-level parameter

used for intra-RAT handovers.This parameter specifies the Ms type andtriggering quantity for events A1 and A2.

The triggering quantity for event A2 forfrequency-priority-based inter-frequencymeasurement is the same as that for event A1for frequency-priority-based inter-frequencymeasurement.


Before delivering the measurement configuration related to event A4, the eNodeB checks whether themeasurement gap has been activated. If the measurement gap has been activated and includes other

measurement gap, the eNodeB does not perform any handling. Otherwise, the eNodeB activates themeasurement gap.

If a UE has performed gap-assisted measurements for a frequency-priority-based inter-frequencyhandover for a period of time (internally set to 3s) but fails to trigger such a handover, the eNodeB willstop the frequency-priority-based inter-frequency measurements.

Parameters (other than parameter for frequency selection) in the measurement configuration forfrequency-priority-based inter-frequency measurement are the same as those for coverage-based inter-frequency measurement. For details, see 4.1.2 Inter-Frequency Measurement.


















The EutranInterNFreq.FreqPriBasedHoMeasFlag parameter specifies the measurement flag for afrequency for frequency-priority-based inter-frequency measurement.

If EutranInterNFreq.FreqPriBasedHoMeasFlag is set to ENABLE(Enable) , the frequency is atarget frequency for frequency-priority-based inter-frequency measurement. If the number oftarget frequencies to be measured exceeds the maximum number allowed by 3GPPspecifications, the eNodeB contains random frequencies in the measurement configuration.

If EutranInterNFreq.FreqPriBasedHoMeasFlag is set to DISABLE(Disable), the selected inter-frequency neighboring cells must have a frequency priority ranging from 17 to 32. Only thefrequencies of these cells are measured. The frequency priority is set by theEutranInterFreqNCell.Bl indHoPr ior i ty parameter. If the number of target frequencies to bemeasured exceeds the maximum number allowed by 3GPP specifications, the eNodeB sorts thefrequencies according to the value of the EutranInterFreqNCell.Bl indHoPr ior i ty parameterand selects the frequencies of the neighboring cells with high priorities.


Frequency-priority-based inter-frequency handovers can be triggered by event A4. Working principles ofevent A4 for triggering frequency-priority-based inter-frequency handovers are the same as those ofevent A4 for triggering coverage-based inter-frequency handovers. For details, see 4.1.3.2 Event A4.

Parameters related to event A4 that triggers frequency-priority-based inter-frequency handovers are thesame as those related to event A4 that triggers service-based inter-frequency handovers. For details, see4.2.3 Inter-Frequency Handover Triggering.


Triggering and Stopping of Blind Handover

Blind handover is triggered when the eNodeB receives an event A1 report from a UE and blind handoveris enabled. Blind handover is enabled when the FreqPriorIFBlindHOSwitch switch under theCellAlgoSwitch.FreqPriori tyHoSwitch parameter is turned on.

Target Selection

The target selection process of frequency-priority-based inter-frequency blind handover is the same asthat of coverage-based inter-frequency blind handover. For details, see 4.1.4 Blind Handover .

In frequency-priority-based blind handover, the target inter-frequency neighboring cell must have a blind-handover priority ranging from 17 to 32. The frequency priority is set by theEutranInterFreqNCell.Bl indHoPr ior i ty parameter.

If an inter-frequency neighboring cell is not configured with a blind-handover priority, the subsequentprocessing depends on the setting of the EutranInterNFreq.FreqPriBasedHoMeasFlag parameter.

If EutranInterNFreq.FreqPriBasedHoMeasFlag is set to ENABLE(Enable) , measurement isperformed. The frequency of the neighboring cell is a target frequency. If the number of targetfrequencies to be measured exceeds the maximum number allowed by 3GPP specifications, theeNodeB contains random frequencies in the measurement configuration.

If EutranInterNFreq.FreqPriBasedHoMeasFlag is set to DISABLE(Disable), measurement isnot performed.


In the handover decision phase, the eNodeB checks the cells in the candidate cell list and determineswhether a handover needs to be initiated and, if so, to which cell the UE is to be handed over.

The candidate cell list varies according to handover type.























The candidate cell list generated for coverage-based inter-frequency handovers is controlled bythe CellAlgoSwitch.CovBasedInterFreqHoMode parameter.

When this parameter is set to HANDOVERIMMEDIATELY , the candidate cell list isgenerated based on measurement report.

When this parameter is set to BASEDONSIGNALSTRENGTH or

BASEDONFREQPRIORITY, the candidate cell list is generated as shown in Figure 4-8.

For other inter-frequency handovers, the candidate cell list is generated based on themeasurement report.

Figure 4-8 Candidate cell list generation procedure







As shown in Figure 4-8, the IntraRatHoComm.CovBasedIfHoWaitingTimer parameter specifies thetimer for candidate cell list generation during coverage-based inter-frequency handovers.

When the timer is set to 0, handover decision is started after candidate cell list is generatedaccording to measurement report.

After the timer expires, handover decision based on frequency priority performs handover attempt

according to the frequency priority sequence specified in the measurement report. If there arefrequencies with the same priority, a random frequency is selected for handover attempt.

If all the cells fail after the handover attempt is complete, the eNodeB waits until the UE sends the nextmeasurement report. After receiving the measurement report, the eNodeB no longer starts the timer towait but performs handover decision immediately.

4.6.1 Target Decision

In the handover decision phase, the eNodeB filters cells in the candidate cell list based on cell loadstatus. Then, the eNodeB determines whether a handover needs to be initiated and, if so, the handoversequence.

Basic Handover Decision

The eNodeB excludes the following cells from the neighboring cell list:

Blacklisted neighboring cells

Neighboring cells with a handover prohibition flag

Neighboring cells that have a different PLMN from the serving cell

These cells will not be filtered out if the inter-PLMN handover switch is turned on. Inter-PLMN handover is controlled by the InterPlmnHoSwitch switch under theENodeBAlgoSwitch.HoAlgoSwi tch parameter.

If the equivalent PLMN switch is turned on, the inter-PLMN list can include the EPLMN list.EPlmnSwitch under the ENodeBAlgoSwitch.HoAlgoSwi tch parameter specifies the

equivalent PLMN switch. Neighboring cells in the areas indicated by the IE Handover Restriction List in the INITIAL

CONTEXT SETUP REQUEST message sent from the MME

When a UE is performing VoIP services, cells that forbid VoIP handovers are also filtered.VoipHoControlSwitch under the ENodeBAlgoSwitch.HoAlgoSwi tch parameter specifies whether toenable this function.

When this switch is turned on, cells specified by EutranVoipHoBlkList are filtered when a UE isperforming VoIP services.

When this switch is turned off, cells specified by EutranVoipHoBlkList are not filtered when aUE is performing VoIP services.

Load Decision

If the handover target cell is an intra-site cell, the source cell checks the load status of the target cells. Ifthe load of any operator's target cell is high, the cell is not selected as the candidate cell. For detailsabout the load status of the target cell, see MLB.

When InterFreqMlbSwitch under the CellAlgoSwitch.MlbAlgoSwi tch parameter is turned on, whetherinter-frequency handover based on frequency priority is triggered is determined by cell load status.ReduceInvalidFreqPriHoSwitch under the ENodeBAlgoSwitch.HoSignal ingOptSwi tch parameterspecifies whether to enable this function.










When this switch is turned on, inter-frequency handover based on frequency priority is nottriggered if the load of the target cell is high.

When this switch is turned off, whether to trigger inter-frequency handover based on frequencypriority is not related to the load of the target cell.

The source eNodeB applies a penalty mechanism on UEs that performs unnecessary handovers when its

handover admission fails. This prevents a large number of initiated handover attempts from affecting thetarget eNodeB, especially when the eNodeB has insufficient resources. Unnecessary handovers include:

Service-based inter-frequency handover

Frequency-Priority-based Inter-Frequency Handover

SPID-based inter-frequency handover back to the HPLMN. For details, see Flexible UserSteering

Sequence Decision

The eNodeB then sends a handover request to the target cell at the top of the filtered candidate cell list. Ifthe handover request fails, the eNodeB sends the handover request to the next target cell, as describedin Table 4-25.

Table 4-25 Sequence of handover requests to be sent by the eNodeB

Candidate Cell ListGenerated by

Sequence of Handover Requests

Measurement A handover request is sent to the cell with the best signal quality.

If the measurement results are the same, the eNodeB assigns the intra-eNodeB cell a higher priority to avoid signaling and data forwardingrequired in an inter-eNodeB handover.

In handover based on frequency priority, a random cell is selected as thetarget cell when the cell measurement results are the same.

Blind Handover A handover request is sent to a cell or frequency that has the highestpriority. If multiple cells have the highest priority, the eNodeB randomlyselects a cell for blind handover.

In handover based on frequency priority, a random cell is selected as thetarget cell when the priorities are the same.

If the handover request fails in all candidate cells:

For a measurement procedure, the eNodeB waits until the UE sends the next measurementreport.

For a blind handover procedure, the eNodeB finishes the handover procedure.

4.6.2 Admission Decision MultiQciHoExecOptSwitch under the ENodeBAlgoSwitch.HoSignal ingOptSwi tch parameter indicateswhether the handover decision is triggered based on the admission result of all QCIs in SPID-basedhandovers to HPLMN and frequency-priority-based handovers.

If this switch is turned on, the handover decision is triggered only when all QCIs are successfullyadmitted.

If this switch is turned off, the handover decision is triggered when any of the QCIs is successfullyadmitted.










The eNodeB provides the ENodeBAlgoSwitch.EutranVoipSupportSwi tch parameter, which preventsUEs performing VoIP services from being handed over to an eNodeB that does not support VoIP.

When this switch is turned on, VoIP services are allowed in the E-UTRAN cell, which means thatthe establishment, handover in, admission, and reestablishment of VoIP services are allowed.

When this switch is turned off, VoIP services are not allowed in the E-UTRAN cell, which means

that the establishment, handover in, admission, and reestablishment of VoIP services are notallowed.

Assume that eNodeB1 cells are neighboring cells of eNodeB2. It is recommended that eNodeB1 cells beadded to the EutranVoipHoBlkList parameter of eNodeB2 if eNodeB1 forbids VoIP service handover in.Otherwise, the handover will fail due to handover penalty.


The eNodeB selects either a handover procedure or a redirection procedure.

The eNodeB selects the handover procedure for all measurement-based handovers.

The procedure selection for blind handover is as follows:

The eNodeB selects the redirection procedure for coverage-based and UL-quality-basedblind handover. Redirections are performed only on non-VoIP UEs, not on VoIP UEs.

The eNodeB selects the handover procedure for frequency-priority-based blind handover.

When the FDD and TDD cells of the same eNodeB are served by different MMEs, only theredirection procedure can be selected for coverage-based inter-frequency handover betweenFDD and TDD cells.

This is because there is a possibility that the MME cannot be changed during a handover insuch a case. For details about such MME configurations, see S1-Flex .

Other execution mechanisms for inter-frequency handover are the same as those for intra-frequencyhandover. For details, see 3.4 Handover Execution.


Signaling procedures for inter-frequency handovers are the same as those for intra-frequency handovers.For details, see 3.5 Signaling Procedures.

5 Related Features


Prerequisite Features

None

Mutually Exclusive Features

None

Impacted Features

None




























None


Coverage-based inter-frequency handovers support inter-frequency blind redirection in the

absence of neighbor relationship configurations. To use inter-frequency blind redirection in theabsence of neighbor relationship configurations, ensure that RAN sharing information about

inter-frequency frequencies is configured.

The parameters for RAN sharing and LOFD-001112 MOCN Flexible Priority Based Campingare mutually exclusive. Therefore, if inter-frequency blind redirection in the absence of neighbor

relationship configurations is used, LOFD-001112 MOCN Flexible Priority Based Camping

cannot be used.

Impacted Features

If LBFD-00201802 Coverage Based Inter-frequency Handover is used, you are advised not touse other inter-frequency handover features for multiple different frequencies. Otherwise, ping-

pong handovers between frequencies may occur due to differences in triggering conditions fordifferent types of inter-frequency handovers.

If other inter-frequency handover features need to be used for multiple frequencies with LBFD-

00201802 Coverage Based Inter-frequency Handover enabled, event A4 thresholds for those

inter-frequency handover features must be properly set. The event A4 threshold for each type of

inter-frequency handover must be higher than the event A2 threshold for coverage-based inter-frequency handover to ensure that a coverage-based inter-frequency measurement is not

triggered immediately after a UE is handed over to the target frequency.



None


None

Impacted Features

Good practice is to avoid enabling multiple inter-frequency handover types (excluding coverage-basedinter-frequency handovers) on multiple E-UTRAN frequencies. If multiple inter-frequency handover typesare enabled on multiple E-UTRAN frequencies, ping-pong handovers may occur due to the diversetriggering conditions of different inter-frequency handover types.

If coverage-based inter-frequency handovers are enabled on multiple E-UTRAN frequencies and anotherinter-frequency handover type is to be enabled on one frequency (for example, F1), ensure that thethreshold for event A4 for this inter-frequency handover type is greater than the threshold for inter-frequency measurement event A2. To further elaborate on the two thresholds mentioned here, thethreshold for event A4 is configured on the eNodeB providing F1, while the threshold for inter-frequencymeasurement event A2 is configured on the eNodeB providing a neighboring E-UTRAN frequency of F1.








None


None

Impacted Features

If LBFD-00201804 Distance Based Inter-frequency Handover is used, you are advised not to useother inter-frequency handover features for multiple different frequencies. Otherwise, ping-pong

handovers between frequencies may occur due to differences in triggering conditions for

different types of inter-frequency handovers.

If other inter-frequency handover features need to be used for multiple frequencies with LBFD-00201804 Distance Based Inter-frequency Handover enabled, event A4 thresholds for thoseinter-frequency handover features must be properly set. The event A4 threshold for each type of

inter-frequency handover must be higher than the event A2 threshold for coverage-based inter-

frequency handover to ensure that a coverage-based inter-frequency measurement is nottriggered immediately after a UE is handed over to the target frequency.

6 Network Impact


System Capacity

No impact.

Network Performance

Coverage-based intra-frequency handovers reduce interference from intra-frequency neighboring cells onan intra-frequency network, decreasing the call drop rate.


System Capacity

No impact.

Network Performance

With coverage-based inter-frequency handovers, the coverage in areas with weak LTE coverage orcoverage holes can be supplemented by inter-frequency neighboring cells, decreasing the call drop rate.


System Capacity


















No impact.

Network Performance

No impact.


System Capacity

No impact.

Network Performance

No impact.

7 Engineering Guidelines

This chapter provides engineering guidelines for mobility management in connection mode.


7.1.1 When to Use Coverage-based Intra-Frequency Handover

Mobility management is fundamental to service continuity. Coverage-based intra-frequencyhandovers are used by default. You are advised to keep this type of handover enabled.


Coverage-based intra-frequency handover is a basic feature and has no special requirements forthe network and UE.

To ensure the performance of coverage-based intra-frequency handover, verify that the E-

UTRAN provides effective and continuous coverage. If there are coverage holes in the E-

UTRAN, coverage-based intra-frequency handover may not achieve satisfactory performance.

In addition, collect information about intra-frequency neighbor relationships to ensure the

integrity of such relationships.

7.1.3 Requirements

Operating Environment

Coverage-based intra-frequency handovers have no requirements for operating environment.

Transmission Networking

Coverage-based intra-frequency handovers have no requirements for transmission networking.





















License

Coverage-based intra-frequency handovers have no requirements for licenses.


This section describes the data that you need to collect for setting parameters. Required data is data thatyou must collect for all scenarios. Collect scenario-specific data when necessary for a specific featuredeployment scenario.

There are three types of data sources:

Network plan (negotiation required): parameter values planned by the operator and negotiatedwith the EPC or peer transmission equipment

Network plan (negotiation not required): parameter values planned and set by the operator

User-defined: parameter values set by users

Required Data

This section describes the data required for configuring neighbor relationships with intra-frequency E-UTRAN cells.

The following table describes the parameters that must be set in the EutranExternalCell managed object(MO) to configure an external E-UTRAN cell. This MO is required only if an intra-frequency neighboringcell is under a different eNodeB from the local cell.

ParameterName

Parameter ID DataSource

Setting Notes

Mobilecountrycode

EutranExternalCell.Mcc Networkplan(negotiationrequired)

This parameter specifies the mobile countrycode (MCC) of the home eNodeB of theexternal E-UTRAN cell. If this external cellworks in RAN sharing mode, set this

parameter to the MCC of the primaryoperator.

This parameter references thecorresponding parameter defined in theCnOperator MO on the peer eNodeB.

Mobilenetworkcode

EutranExternalCell.Mnc Networkplan(negotiationrequired)

This parameter specifies the mobile networkcode (MNC) of the home eNodeB of theexternal E-UTRAN cell. If this external cellworks in RAN sharing mode, set thisparameter to the MNC of the primaryoperator.


eNodeB ID EutranExternalCell.eNodeBId Networkplan(negotiationrequired)

This parameter specifies the ID of the homeeNodeB of the external E-UTRAN cell. Ituniquely identifies the eNodeB within theentire network.






ParameterName


Setting Notes

This parameter references thecorresponding parameter defined in theeNodeBFunction MO on the peer eNodeB.

Cell ID EutranExternalCell.CellId Networkplan(negotiationrequired)

This parameter specifies the ID of theexternal E-UTRAN cell. It uniquely identifiesa cell within an eNodeB.

This parameter references thecorresponding parameter defined in the CellMO on the peer eNodeB.

DownlinkEARFCN

EutranExternalCell.DlEarfcn Networkplan(negotiationrequired)

This parameter specifies the DL EARFCN ofthe external E-UTRAN cell.

Physicalcell ID

EutranExternalCell.PhyCellId Networkplan(negotiationrequired)

This parameter references thecorresponding parameter defined in the CellMO on the peer eNodeB.

Trackingarea code

EutranExternalCell.Tac Networkplan(negotiationrequired)

This parameter references thecorresponding parameter defined in theCnOperatorTa MO on the peer eNodeB.

(Optional, required only if the home eNodeB of the external E-UTRAN cell works in RAN sharing withcommon carrier mode) The following table describes the parameters that must be set in theEutranExternalCellPlmn MO to configure an additional PLMN ID (representing a secondary operator) foran external E-UTRAN cell.

ParameterName


Setting Notes

Mobilecountrycode

EutranExternalCellPlmn.Mc c Networkplan(negotiationrequired)

This parameter specifies the MCC ofthe primary operator.

This parameter references thecorresponding parameter defined inthe CnOperator MO on the peereNodeB.

Mobilenetwork

code

EutranExternalCellPlmn.Mn c Networkplan

(negotiationrequired)

This parameter specifies the MNC ofthe primary operator.


eNodeB ID EutranExternalCellPlmn.eNodeBId Networkplan

This parameter specifies the ID of thehome eNodeB of the external E-



ParameterName


Setting Notes

(negotiationrequired)

UTRAN cell. It uniquely identifies theeNodeB within the entire network.

This parameter references thecorresponding parameter defined inthe eNodeBFunction MO on the peereNodeB.

Cell ID EutranExternalCellPlmn.CellId Networkplan(negotiationrequired)

This parameter specifies the ID of theexternal E-UTRAN cell. It uniquelyidentifies a cell within an eNodeB.

This parameter references thecorresponding parameter defined inthe Cell MO on the peer eNodeB.

Share

mobilecountrycode

EutranExternalCellPlmn.ShareMcc Network

plan(negotiationrequired)

This parameter specifies the MCC of

the secondary operator for theexternal E-UTRAN cell.


Sharemobilenetworkcode

EutranExternalCellPlmn.ShareMnc Networkplan(negotiationrequired)

This parameter specifies the MNC ofthe secondary operator for theexternal E-UTRAN cell.

This parameter references the

corresponding parameter defined inthe CnOperator MO on the peereNodeB.

(Optional, required only if the neighboring E-UTRAN cell is a multi-band cell) The following tabledescribes the parameters that must be set in the EutranExternalCellBand MO to configure thesecondary band for an external E-UTRAN cell.

ParameterName

Parameter ID Data Source Setting Notes

Mobilecountrycode

EutranExternalCellBand.Mc c Network plan(negotiationrequired)

This parameter specifies the MCC ofthe home eNodeB of the neighboringcell. If this neighboring cell works in

RAN sharing mode, set thisparameter to the MCC of the primaryoperator.

This parameter references thecorresponding parameter defined inthe eNodeB MO on the peereNodeB.



ParameterName


Mobilenetworkcode

EutranExternalCellBand.Mn c Network plan(negotiationrequired)

This parameter specifies the MNC ofthe home eNodeB of the neighboringcell. If this neighboring cell works inRAN sharing mode, set thisparameter to the MNC of the primaryoperator.


eNodeB ID EutranExternalCellBand.eNodeBId Network plan(negotiationrequired)

This parameter specifies the ID ofthe eNodeB of the neighboring cell. Ituniquely identifies the eNodeB withinthe entire network.


Cell ID EutranExternalCellBand.CellId Network plan(negotiationrequired)

This parameter specifies the ID ofthe neighboring E-UTRAN cell. Ituniquely identifies a cell within aneNodeB.

This parameter references thecorresponding parameter defined inthe Cell MO on the peer eNodeB.

Frequencyband

EutranExternalCellBand.FreqBand Network plan(negotiationrequired)

This parameter specifies otherfrequency band in which the celloperates.

Set this parameter to theprimary/secondary band identifier ofthe multi-band inter-frequencyneighboring cell.

The following table describes the parameters that must be set in the EutranIntraFreqNCell MO toconfigure the neighbor relationship with an intra-frequency E-UTRAN cell.

ParameterName


Setting Notes

Local cellID

EutranIntraFreqNCell.LocalCel l Id Networkplan(negotiationnotrequired)

Ensure that this parameter has been setin a Cell MO.



ParameterName


Setting Notes

Mobilecountrycode

EutranIntraFreqNCell.Mc c Networkplan(negotiationrequired)

This parameter specifies the MCC of thehome eNodeB of the intra-frequencyneighboring E-UTRAN cell. If thisneighboring E-UTRAN cell works inRAN sharing mode, set this parameterto the MCC of the primary operator.


Mobilenetworkcode

EutranIntraFreqNCell.Mn c Networkplan(negotiationrequired)

This parameter specifies the MNC of thehome eNodeB of the neighboring E-UTRAN cell. If this neighboring E-UTRAN cell works in RAN sharingmode, set this parameter to the MNC ofthe primary operator.


eNodeB ID EutranIntraFreqNCell.eNodeBId Networkplan(negotiationrequired)

This parameter specifies the ID of thehome eNodeB of the neighboring E-UTRAN cell. It uniquely identifies theeNodeB within the entire network.

This parameter references thecorresponding parameter defined in theeNodeBFunction MO on the peer

eNodeB.

Cell ID EutranIntraFreqNCell.CellId Networkplan(negotiationrequired)

This parameter specifies the ID of theneighboring E-UTRAN cell. It uniquelyidentifies a cell within an eNodeB.

This parameter references thecorresponding parameter defined in theCell MO on the peer eNodeB.

Scenario-specific Data

The following table describes the parameter that must be set in the ENodeBAlgoSwitch MO to configurecoverage-based intra-frequency handover.

Parameter Name


Setting Notes

Handover Algoswitch

ENodeBAlgoSwitch.HoAlgoS

wi tch Networkplan(negotiation notrequired)

To enable coverage-based intra-frequencyhandover, select theIntraFreqCoverHoSwitch(IntraFreqCoverHoSwitch) check box under this parameter.



By default, the intra-frequency handover parameter group Group0 is used for services with all QCIs. Toapply different intra-frequency handover parameter groups to services based on the QCI, thecorresponding parameter group ID must be changed.

The following table describes the parameter that must be set in the CellStandardQci MO to configureparameter groups for services with standard QCIs.

ParameterName


Setting Notes

Local cellID

CellStandardQci.LocalCel l Id Networkplan(negotiationnotrequired)

Ensure that this parameter hasbeen set in a Cell MO based onthe network plan.

QoS ClassIndication

CellStandardQci.Qci Networkplan(negotiationnotrequired)

This parameter specifies the indexof the standard QCI for which theparameter group is configured.

Intrafreqhandovergroup ID

CellStandardQci.IntraFreqHoGroupId Networkplan(negotiationnotrequired)

This parameter specifies the indexof the intra-frequency handoverparameter group.

QCIPriority ForHandover

CellStandardQci.QciPriori tyForHo Networkplan(negotiationnotrequired)

This parameter specifies prioritymapping the QCI.

The following table describes the parameter that must be set in the CellExtendedQci MO to configure

parameter groups for services with extended QCIs.

ParameterName


Setting Notes

ExtendedQCI

CellExtendedQci.ExtendedQci Networkplan(negotiationnotrequired)

Set this parameter to the index ofthe extended QCI for which theparameter group is configured.

Local cellID

CellExtendedQci.LocalCel l Id Networkplan(negotiation

notrequired)

Ensure that this parameter hasbeen set in a Cell MO based on thenetwork plan.


CellExtendedQci.IntraFreqHoGroupId Networkplan(negotiationnotrequired)

Set this parameter to the index ofthe corresponding parametergroup.



The following table describes the parameter that must be set in the EutranIntraFreqNCell MO toconfigure measurement priorities for intra-frequency neighboring cells.

ParameterName


Setting Notes

Cell

MeasurePriority

EutranIntraFreqNCell.CellMeasPriori ty Network

plan(negotiationnotrequired)

Neighboring cells with optimal

network coverage are easy to bemeasured and quickly meethandover conditions. You areadvised to set this parameter toHIGH_PRIORITY(High Priority) for such neighboring cells and setthis parameter toLOW_PRIORITY(Low Priority) for other neighboring cells.

7.1.5 Activation

Using the CME to Perform Batch Configuration for Newly Deployed eNodeBs

Enter the values of related parameters in a summary data file, which also contains other data for the neweNodeBs to be deployed. Then, import the summary data file into the Configuration Management Express(CME) for batch configuration. For detailed instructions, see section "Creating eNodeBs in Batches" in theinitial configuration guide for the eNodeB.

The summary data file may be a scenario-specific file provided by the CME or a customized file,depending on the following conditions:

Related managed objects (MOs) are contained in a scenario-specific summary data file. In thissituation, set the parameters in the MOs, and then verify and save the file.

Some related MOs are not contained in a scenario-specific summary data file. In this situation,customize a summary data file to include the MOs before you can set the parameters.

Related MOs and parameters in each scenario are listed as follows:

Table 7-1 Parameters related to coverage-based intra-frequency handovers

MO Sheet in the SummaryData File

Parameter Group Remarks

ENodeBAlgoSwitch User-defined sheet

ENodeBAlgoSwitch isrecommended.

Handover Algo switch A list-typesheet isrecommended.

EutranExternalCell User-defined sheet

EutranExternalCell isrecommended.

Mobile country code, Mobilenetwork code, eNodeB identity,Cell identity, Downlink EARFCN,Uplink EARFCN indicator, UplinkEARFCN, Physical cell identity,Tracking area code, Cell name

A list-typesheet isrecommended.

EutranExternalCellPlmn User-defined sheet Mobile country code, Mobilenetwork code, eNodeB identity,Cell identity, Share mobile









EutranExternalCellPlmn is recommended.

country code, Share mobilenetwork code

EutranIntraFreqNCell User-defined sheet

EutranIntraFreqNCell isrecommended.

Local cell identity, Mobile

country code, Mobile networkcode, eNodeB identity, Cellidentity, Cell individualoffset(dB), Cell offset(dB), Nohandover indicator, No removeindicator, ANR flag, Local cellname, Neighbour cell name

A list-type

sheet isrecommended.

Using the CME to Perform Batch Configuration for Existing eNodeBs

Batch reconfiguration using the CME is the recommended method to activate a feature on existingeNodeBs. This method reconfigures all data, except neighbor relationships, for multiple eNodeBs in asingle procedure. The procedure is as follows:

1. Choose CME > Advanced > Customize Summary Data File (U2000 client mode), or chooseAdvanced > Customize Summary Data File (CME client mode), to customize a summarydata file for batch reconfiguration.

NOTE:

For context-sensitive help on a current task in the client, press F1.

2. Choose CME > LTE Application > Export Data > Export Base Station Bulk ConfigurationData (U2000 client mode), or choose LTE Application > Export Data > Export Base StationBulk Configuration Data (CME client mode), to export the eNodeB data stored on the CME

into the customized summary data file.3. In the summary data file, set the parameters in the MOs listed in Table 7-1 and close the file.4. Choose CME > LTE Application > Import Data > Import Base Station Bulk Configuration

Data (U2000 client mode), or choose LTE Application > Import Data > Import Base StationBulk Configuration Data (CME client mode), to import the summary data file into the CME.

5. Choose CME > Planned Area > Export Incremental Scripts (U2000 client mode), or chooseArea Management > Planned Area > Export Incremental Scripts (CME client mode), toexport and activate the incremental scripts.

Using the CME to Perform Single Configuration

On the CME, set the parameters listed in the "Data Preparation" section for a single eNodeB. Theprocedure is as follows:

1. In the planned data area, click Base Station in the upper left corner of the configurationwindow.

2. In area 1 shown in Figure 7-1, select the eNodeB to which the MOs belong.

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Figure 7-1 MO search and configuration window

3. On the Search tab page in area 2, enter an MO name, for example, CELL.4. In area 3, double-click the MO in the Object Name column. All parameters in this MO are

displayed in area 4.5. Set the parameters in area 4 or 5.6. Choose CME > Planned Area > Export Incremental Scripts (U2000 client mode), or choose

Area Management > Planned Area > Export Incremental Scripts (CME client mode), toexport and activate the incremental scripts.

Using MML Commands

1. Run the MOD ENODEBALGOSWITCH command, and select the IntraFreqCoverHoSwitch option under the Handover Algo switch parameter.

2. Run the following commands to add neighbor relationships with intra-frequency E-UTRANcells:

a. (Optional) ADD EUTRANEXTERNALCELL, which is required when the intra-frequency

neighboring cell is under a different eNodeB from the local cell.b. (Optional) ADD EUTRANEXTERNALCELLPLMN, which is used to configure the PLMN

list for an external E-UTRAN cell when the neighboring E-UTRAN cell works in RANsharing mode.

c. ADD EUTRANINTRAFREQNCELL

MML Command Examples

//Activating coverage-based intra-frequency handover



MOD ENODEBALGOSWITCH: HoAlgoSwitch=IntraFreqCoverHoSwitch-1;

//Adding intra-frequency E-UTRAN neighboring cells

ADD EUTRANEXTERNALCELL: Mcc="460", Mnc="20", eNodeBId=123, CellId=0,

DlEarfcn=2350, UlEarfcnCfgInd=NOT_CFG, PhyCellId=101, Tac=1; ADDEUTRANEXTERNALCELLPLMN: Mcc="460", Mnc="20", eNodeBId=123, CellId=0,ShareMcc="460", ShareMnc="22"; ADD EUTRANINTRAFREQNCELL: LocalCellId=0,

Mcc="460", Mnc="20", eNodeBId=123, CellId=0;


The observation procedure is as follows:

1. Trace messages over the Uu interface on the U2000 client after UEs access the network.Check the RRC_CONN_RECFG message. If the message contains measurementconfiguration of event A3 for a coverage-based intra-frequency handover, you can infer thatcoverage-based intra-frequency handover has been activated.

2. Trace messages over the Uu interface while the UE is moving towards an intra-frequencyneighboring cell. Check the RRC_CONN_RECFG message, which is a handover command. Ifthe message contains target cell access information, you can infer that coverage-based intra-

frequency handover has been triggered.

7.1.7 Deactivation

Using the CME to Perform Batch Configuration

Batch reconfiguration using the CME is the recommended method to deactivate a feature on eNodeBs.This method reconfigures all data, except neighbor relationships, for multiple eNodeBs in a singleprocedure. The procedure for feature deactivation is similar to that for feature activation described inUsing the CME to Perform Batch Configuration for Existing eNodeBs. In the procedure, modify relatedparameters described below.

Table 7-2 Parameters related to coverage-based intra-frequency handovers

MO Sheet in theSummary Data File

Parameter Group Setting Notes

ENodeBAlgoSwitch ENodeBAlgoSwitch Handover Algoswitch

Clear theIntraFreqCoverHoSwitch check box.


On the CME, set the parameters listed in each scenario for a single eNodeB. For detailed instructions,see Using the CME to Perform Single Configuration for feature activation.

Using MML Commands

To deactivate coverage-based intra-frequency handover, disable its algorithm by running the MODENODEBALGOSWITCH command and clear the IntraFreqCoverHoSwitch option under the HandoverAlgo switch parameter.


//Deactivating coverage-based intra-frequency handover

MOD ENODEBALGOSWITCH: HoAlgoSwitch=IntraFreqCoverHoSwitch-0;





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Coverage-based intra-frequency handovers ensure service continuity when users move around. How wellthese handovers serve this purpose reflects their performance. After activating coverage-based intra-frequency handover, check the following counters to monitor and evaluate handover performance:

Success rate of X2 and S1 handovers. The interface-specific statistics helps locating thehandover failure cause. The related counters are: Intra-eNB Intra-frequency Handover Out Success Rate Inter-eNB Intra-frequency Handover Out Success Rate

Abnormal Release Rate indicating the service drop rate

If the handover success rate is low and the service drop rate is high, the performance of coverage-basedintra-frequency handover is poor. In this situation, check the related parameter settings and networkcoverage.


Intra-Frequency Handover Parameters

Intra-frequency handover parameters are contained in the IntraFreqHoGroup MO.

Parameter Name


Setting Notes

Local cellID

IntraFreqHoGroup.LocalCel l Id Networkplan(negotiation notrequired)

Ensure that this parameter has beenset in a Cell MO based on thenetwork plan.


IntraFreqHoGroup.IntraFreqHoGroupId Networkplan(negotiati

on notrequired)

This parameter specifies the ID ofthe parameter group related to intra-frequency handovers.

If you want to set different intra-frequency handover parameters forservices with a specific QCI, youmust create a parameter group, andreference the parameter group ID tothe corresponding QCI.

Intrafreqhandoverhysteresis

IntraFreqHoGroup.IntraFreqHoA3Hyst Networkplan(negotiation notrequired)

This parameter specifies thehysteresis for event A3 associatedwith intra-frequency handover. Alarger hysteresis value causes alower probability of triggering event

A3, affecting user experience. Asmaller hysteresis value causes ahigher probability of triggering event A3 but also a higher probability ofincorrect handover decisions andping-pong handovers.

It is recommended that the defaultvalue be used. You can suitably









Parameter Name


Setting Notes

decrease the value in areas withslight signal fluctuation.

Intrafreq

handoveroffset

IntraFreqHoGroup.IntraFreqHoA3Offse

t

Network

plan(negotiation notrequired)

This parameter specifies the offset

for event A3 associated with intra-frequency handover. A larger valuecauses a lower probability oftriggering event A3. A smaller valuecauses a higher probability.

It is recommended that you adjustthe parameter value based on theapplication scenario. Increase theparameter value if premature intra-frequency handovers occur.Decrease the parameter value ifdelayed intra-frequency handovers

occur.

Intrafreqhandovertime totrigger

IntraFreqHoGroup.IntraFreqHoA3Time

ToTrig Networkplan(negotiation notrequired)

This parameter specifies the time-to-trigger for event A3 associated withintra-frequency handover. Setting anappropriate triggering delayeffectively reduces the averagenumber of handovers and thenumber of wrong handovers,preventing unnecessary handovers.The average number of handovershas a negative correlation with thetime-to-trigger. At the same time, an

excessively large value of the time-to-trigger results in a high risk ofservice drops.

It is recommended that you adjustthe parameter value withIntraFreqHoGroup.IntraFreqHoA3 Offset based on the applicationscenario. Increase the parametervalue if premature intra-frequencyhandovers occur. Decrease theparameter value if delayed intra-frequency handovers occur.

Cell Individual Offset for Intra-Frequency Neighboring Cells

The following table provides the parameter that must be set in the EutranIntraFreqNCell MO to adjustcell individual offset for the intra-frequency neighboring cells.



ParameterName


Setting Notes

Cellindividualoffset

EutranIntraFreqNCell.Cell IndividualOffset Networkplan(negotiationnotrequired)

This parameter affects theprobability of reporting intra-frequency measurementevents. A larger parametervalue indicates a higherprobability.

If there are multiple target cellsfor the intra-frequencyhandover and relatedhandover parameters need tobe optimized, you candecrease this parameter valuefor a neighboring cell to reducethe possibility of the handoverto the neighboring cell, or youcan increase this parametervalue for a neighboring cell toraise the possibility of thehandover to the neighboringcell.

Intra-RAT Intra-Frequency Handover Parameters

Intra-RAT intra-frequency handover parameters are contained in the IntraRatHoComm MO.

ParameterName


Setting Notes

Max reportcell number

IntraRatHoComm.IntraRatHoMaxRprtCel l Networkplan(negotiationnotrequired)

This parameter specifiesthe maximum number ofcells to be included in eachintra-frequency or inter-frequency measurementreport after thecorresponding event istriggered. Set thisparameter to a larger valueif the eNodeB requiresmore candidate cells tomake a handover decision. An excessively large value,however, causes a wasteof air interface resources.

It is recommended that thedefault value be used.

Measurementreportamount

IntraRatHoComm.In traRatHoRprtAmount Networkplan(negotiationnotrequired)

This parameter specifiesthe number of intra-frequency or inter-frequency periodicalmeasurement reports to be



ParameterName


Setting Notes

sent after thecorresponding event istriggered. Set this

parameter to a larger valueif the eNodeB requiresmore measurement reportsto make a handoverdecision. An excessivelylarge parameter value,however, causes a wasteof air interface resources.


A3measurement

triggerquantity

IntraRatHoComm.IntraFreqHoA3TrigQuan Networkplan

(negotiationnotrequired)

This parameter specifiesthe triggering quantity for

event A3 associated withintra-frequency handover.The parameter can beeither RSRP or RSRQ.RSRQ-basedmeasurement resultsreflect signal quality in realtime, whereas RSRP-based measurementresults are stable with littlesignal fluctuation.

It is recommended that the

default value be used.

A3measurementreportquantity

IntraRatHoComm.IntraFreqHoA3RprtQuan Networkplan(negotiationnotrequired)

This parameter specifiesthe reporting quantity to beincluded in themeasurement reports afterevent A3 associated withintra-frequency handover istriggered. The parametercan be either the same asthe triggering quantity forthis event A3 or both RSRPand RSRQ. That is, themeasurement results of theserving cell andneighboring cells can beRSRP-based, RSRQ-based, or both in A3-related measurementreports.



ParameterName


Setting Notes


Intrafreq

measurementreport interval

IntraRatHoComm.IntraFreqHoRprtInterval Network


This parameter specifies

the interval between thereports that are triggeredby event A3 associatedwith intra-frequencyhandover. A smaller valuecauses more measurementreports and greaterconsumption of air interfaceresources, but a higherprobability of triggeringhandovers. An excessivelylarge parameter value,however, causes a long

delay in retries and a lowhandover success rate.



Fault description

An eNodeB may not initiate a handover procedure upon receipt of an event A3 measurement report.

Fault handling

When this problem occurs, perform the following steps to determine whether it has occurred because thetarget cell has not been configured as a neighboring cell:

1. Check the messages over the Uu interface and locate the PCI of the neighboring cell in themeasurement report.

2. Run the LST EUTRANEXTERNALCELL command to list all external E-UTRAN cells of theeNodeB, run the LST CELL command to list all local cells of the eNodeB, and check these listsfor the cell whose PCI equals the PCI found in the previous step.

If this cell can be found, go to 4.

If this cell cannot be found, the target cell has not been configured as an external cell. Tosolve this problem, go to 3.

3. Find out the CGI of the cell whose PCI equals the PCI found in 1 in the command output in 2.

Then, run the ADD EUTRANINTRAFREQNCELL command to add the CGI to theEutranIntraFreqNCell MO.4. Find out the CGI of the cell whose PCI equals the PCI found in 1 in the command output in 2.

Then, run the ADD EUTRANEXTERNALCELL and ADD EUTRANINTRAFREQNCELLcommands to add the CGI to the EutranExternalCell and EutranIntraFreqNCell MOs,respectively.




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7.2.1 When to Use Coverage-based Inter-Frequency Handover

Mobility management is fundamental to service continuity. Coverage-based inter-frequency handoversare used by default. You are advised to keep this type of handover enabled.

If the live network does not require inter-frequency networking, you can disable coverage-based inter-frequency handover.


If blind handovers or redirections are required to implement inter-frequency handovers, collect theinformation about the neighboring cells to which blind handovers or redirections will be allowed as well astheir blind-handover priorities.

The information to be collected before deploying coverage-based inter-frequency handover includes theinformation to be collected before deploying coverage-based intra-frequency handover.

Collect UE information to determine whether the eNodeB needs to handle UEs that report an abnormalfrequency-supporting capability.

In addition to the information described in 7.1.2 Required Information, collect the information about thecoverage at the inter-frequency handover area. This information serves as a basis for setting the

thresholds used to trigger events A1, A2, and A4.The event A2 threshold for coverage-based inter-frequency handover and the event A2 threshold forcoverage-based inter-RAT handover can be separately set. If users expect coverage-based inter-frequency handover to be triggered earlier than coverage-based inter-RAT handover, the event A2threshold for coverage-based inter-frequency handover must be set to a value greater than the event A2threshold for coverage-based inter-RAT handover.

7.2.3 Requirements


None


None

License

None







Required Data



















This section describes the data required for configuring neighbor relationships with inter-frequency E-UTRAN cells.

The following table describes the parameters that must be set in the EutranInterNFreq MO to configure aneighboring E-UTRAN frequency.

Parameter

Name


Local cell ID EutranInterNFreq.LocalCel l Id Network plan(negotiation notrequired)

Ensure that this parameterhas been set in a Cell MO.

DownlinkEARFCN

EutranInterNFreq.DlEarfcn Network plan(negotiation notrequired)

This parameter specifies theDL EARFCN of the cells onthe neighboring E-UTRANfrequency.

This parameter referencesthe corresponding parameterdefined in the Cell MO on the

peer eNodeB.


EutranInterNFreq.MeasBandWidth Network plan(negotiation notrequired)

This parameter referencesthe corresponding parameterdefined in the Cell MO on thepeer eNodeB.

NOTE:

If an inter-frequency neighboring cell is a multi-band cell, the EARFCN in the secondary band also needsto be added in the EutranInterNFreq MO. For details about the relationship between the band andEARFCN, see section 5.7.3 in 3GPP TS 36.101 V10.2.1 (2011-04).

For details about multi-band cells, see Cell Management.

(Optional, required only if an inter-frequency neighboring cell is under a different eNodeB from the localcell) Collect the parameters in the EutranExternalCell MO used to configure an external E-UTRAN cell.For details about the key parameters in this MO, see 7.1.4 Data Preparation.

(Optional, required only if a neighboring E-UTRAN cell is a multi-band cell) Collect the parameters in theEutranExternalCellBand MO used to configure the secondary band for an external E-UTRAN cell. Fordetails about the key parameters in this MO, see 7.1.4 Data Preparation.

(Optional, required only if the home eNodeB of the external E-UTRAN cell works in RAN sharing withcommon carrier mode and multiple operators share the same external E-UTRAN cell) Collect theparameters in the EutranExternalCellPlmn MO used to configure an additional PLMN ID for an externalE-UTRAN cell. For details about the key parameters in this MO, see 7.1.4 Data Preparation.

The following table describes the parameters that must be set in the EutranInterFreqNCell MO toconfigure the neighbor relationship with an inter-frequency E-UTRAN cell.















ParameterName


Setting Notes

Local cellID

EutranInterFreqNCell.LocalCel l Id Networkplan(negotiationnotrequired)

Ensure that this parameter has beenset in a Cell MO.

Mobilecountrycode

EutranInterFreqNCell.Mc c Networkplan(negotiationrequired)

This parameter specifies the MCC ofthe home eNodeB of the inter-frequency neighboring E-UTRAN cell. Ifthis neighboring E-UTRAN cell works inRAN sharing mode, set this parameterto the MCC of the primary operator.

This parameter references thecorresponding parameter defined in theeNodeB MO on the peer eNodeB.

Mobilenetworkcode

EutranInterFreqNCell.Mn c Networkplan(negotiationrequired)

This parameter specifies the MNC ofthe home eNodeB of the neighboring E-UTRAN cell. If this neighboring E-UTRAN cell works in RAN sharingmode, set this parameter to the MNC ofthe primary operator.


eNodeB ID EutranInterFreqNCell.eNodeBId Networkplan(negotiationrequired)

This parameter specifies the ID of thehome eNodeB of the neighboring E-UTRAN cell. It uniquely identifies theeNodeB within the entire network.


Cell ID EutranInterFreqNCell.CellId Networkplan(negotiationrequired)

This parameter specifies the ID of theneighboring E-UTRAN cell. It uniquelyidentifies a cell within an eNodeB.

This parameter references thecorresponding parameter defined in theCell MO on the peer eNodeB.


The following table describes the parameter that must be set in the ENodeBAlgoSwitch MO to configurecoverage-based inter-frequency handover.



Parameter Name


Setting Notes

Handover Algoswitch

ENodeBAlgoSwitch.HoAlgoSwi t

ch Networkplan(negotiation notrequired)

To enable coverage-based inter-frequencyhandover, select theInterFreqCoverHoSwitch(InterFreqCoverHoSwitch) check box under this parameter.

To reduce the number of signaling messagesover the air interface, clear theEmcBlindHoA1Switch(EmcBlindHoA1Switch) check box under this parameter.

To reduce the call drop rate, select theEmcInterFreqBlindHoSwitch(EmcInterFreqBlindHoSwitch) check box under thisparameter.

CompatibilityControlSwitch

ENodeBAlgoSwitch.Compat ib i l i

tyCtr lSwi tch Networkplan(negotiation notrequired)

It is recommended that theUECapRprtAbnormalCtrlSwitch option of

this parameter be selected when the UEreporting capability is abnormal.

By default, the inter-frequency handover parameter group Group0 is used for services with all QCIs. Toapply different inter-frequency handover parameter groups to services based on the QCI, thecorresponding parameter group ID must be changed.

The following table describes the parameters that must be set in the CellStandardQci MO to configureinter-frequency handover parameter groups for services with standard QCIs.

Parameter

Name

Parameter ID Data

Source

Setting Notes

Local cellID

CellStandardQci.LocalCel l Id Networkplan(negotiationnotrequired)

Ensure that this parameter hasbeen set in a Cell MO based on thenetwork plan.

QoS ClassIndication

CellStandardQci.Qci Networkplan(negotiationnotrequired)

This parameter specifies thestandard QCI for which theparameter group is configured.

Interfreq

handovergroup ID

CellStandardQci.InterFreqHoGroupId Network


This parameter specifies the index

of the inter-frequency handoverparameter group.

QCIPriority ForHandover

CellStandardQci.QciPriori tyForHo Networkplan(negotiation

This parameter specifies prioritymapping the QCI.



ParameterName


Setting Notes

notrequired)

The following table describes the parameters that must be set in the CellExtendedQci MO to configureinter-frequency handover parameter groups for services with extended QCIs.

ParameterName


ExtendedQCI

CellExtendedQci.ExtendedQci Network plan(negotiationnot required)

Set this parameter to the index ofthe extended QCI for which theparameter group is configured.

Local cellID

CellExtendedQci.LocalCel l Id Network plan(negotiationnot required)

Ensure that this parameter hasbeen set in a Cell MO based onthe network plan.

Interfreq

handovergroup ID

CellExtendedQci.InterFreqHoGroupId Network plan

(negotiationnot required)

Set this parameter to the index of

the corresponding parametergroup.

The following table describes the parameters that must be set in the EutranInterFreqNCell MO toconfigure blind handover priorities and measurement priorities for inter-frequency neighboring cells.

ParameterName


Setting Notes

BlindhandoverPriority

EutranInterFreqNCell.Bl indHoPr ior i ty Networkplan(negotiationnot

required)

If this parameter value is set to 0,blind handovers and frequency-priority-based handovers cannotbe performed. The values 1 to 16

indicate blind-handover priorities.Multiple neighboring cells can beconfigured with the same blind-handover priority. If multipleneighboring cells have the highestblind-handover priority, theeNodeB randomly selects onefrom them.

The values 17 to 32 indicate thepriorities for frequency-priority-based handovers. Set thisparameter (with a value ranging

from 1 to 16) only for those inter-frequency neighboring cells thathave overlapped coverage withthe serving cell. Set this parameterto a larger value for a neighboringcell that has wider overlappedcoverage or a lower frequency.



ParameterName


Setting Notes

Set this parameter to 0 for all inter-frequency neighboring cells if nointer-frequency neighboring cells

have overlapped coverage withthe serving cell.

CellMeasurePriority

EutranInterFreqNCell.CellMeasPriori ty Networkplan(negotiationnotrequired)

Neighboring cells with optimalnetwork coverage are easy to bemeasured and quickly meethandover conditions. You areadvised to set this parameter toHIGH_PRIORITY(High Priority) for such neighboring cells and setthis parameter toLOW_PRIORITY(Low Priority) for other neighboring cells.

The following table describes the parameters that must be set in the EutranInterNFreq MO to configurethe event for triggering a coverage-based inter-frequency handover and to configure the frequency priorityused during the selection of a target frequency for blind redirection.

ParameterName


Setting Notes

Inter-FreqHO triggerEventType

EutranInterNFreq.InterFreqHoEventType Networkplan(negotiationnotrequired)

This parameter specifies theevent for triggering a coverage-based inter-frequencyhandover. It can be set to event A3, event A4, or event A5.

Interference may be strongin the following scenarios:overlapping scenario,inter-frequency with thesame bandwidth, andinter-frequency in thesame frequency band.Event A3 is recommendedfor coverage-based inter-frequency handovers insuch scenarios as itprovides better handoverperformance.

When the interference oftwo cells is irrelevant, theabsolute threshold ofsignal quality is used asthe handover criterion.Event A4 is recommendedfor coverage-based inter-frequency handovers insuch scenario.



ParameterName


Setting Notes

There is no recommendedscenario for event A5.

Connectfrequencypriority

EutranInterNFreq.ConnFreqPriori ty Networkplan(negotiationnotrequired)

Based on the frequency priorityspecified by this parameter, theeNodeB selects a targetfrequency for blind redirection orcontains a frequency in ameasurement configuration. Alarger value indicates a higherpriority. If this priority is set to 0for a frequency, this frequencyis not selected as the targetfrequency for a blind redirection.Multiple frequencies can beconfigured with the same

priority. If multiple frequencieshave the highest priority, theeNodeB randomly selects onefrom them.

You are advised to set thisparameter for frequencies withcontinuous coverage. If thereare multiple frequencies withcontinuous coverage, set thisparameter to a larger value for afrequency in a lower frequencyband. Set this parameter to 0 for

a frequency with non-continuous coverage.

(Optional, required for only coverage-based inter-frequency handovers) The following table describes theparameters that must be set in the CnOperatorHoCfg MO to configure the RSRP threshold offset andpriorities for TDD/FDD frequencies during the selection of the target cells for coverage-based inter-frequency handovers.

Parameter Name


Setting Notes

CNOperator

ID

CnOperatorHoCfg.CnOperatorId Networkplan

(negotiation notrequired)

This parameter specifies the ID of anoperator and is defined in the

CnOperator MO.

Set this parameter to the ID of theoperator that needs to be configuredwith a priority.

FirstRATPriority

CnOperatorHoCfg.FirstRatPri Networkplan(negotiati

This parameter specifies the priorities ofE-UTRAN TDD and E-UTRAN FDD. Toprioritize E-UTRAN TDD or E-UTRANFDD, set this parameter to



Parameter Name


Setting Notes

on notrequired)

EUTRAN_TDD or EUTRAN_FDD. Togive E-UTRAN TDD and E-UTRANFDD the same priority, set this

parameter to EUTRAN.

Set this parameter based on the actualconditions.

SecondRATPriority

CnOperatorHoCfg.SecondRatPri Networkplan(negotiation notrequired)

This parameter specifies the priorities ofE-UTRAN TDD and E-UTRAN FDD. Toprioritize E-UTRAN TDD or E-UTRANFDD, set this parameter toEUTRAN_TDD or EUTRAN_FDD. IfFirstRatPri is set to EUTRAN, setSecondRatPri to NULL, indicating thatE-UTRAN TDD and E-UTRAN FDD arenot prioritized.


LTETDDinter-freq A2Threshold RSRPOffset

CnOperatorHoCfg.TddIfHoA2ThdRsr

pOffset Networkplan(negotiation notrequired)

This parameter value plus the value ofInterFreqHoGroup.InterFreqHoA2Thd Rsrp orInterFreqHoGroup.A3InterFreqHoA2T hdRsrp is the offset of the RSRPthreshold for LTE TDD inter-frequencymeasurement event A2.

Set this parameter based on the actual

conditions.

LTEFDDinter-freq A2Threshold RSRPOffset

CnOperatorHoCfg.FddIfHoA2ThdRsr

pOffset Networkplan(negotiation notrequired)

This parameter value plus the value ofInterFreqHoGroup.InterFreqHoA2Thd Rsrp orInterFreqHoGroup.A3InterFreqHoA2T hdRsrp is the offset of the RSRPthreshold for LTE FDD inter-frequencymeasurement event A2.


(Optional, required for only coverage-based inter-frequency handovers) The following table describes theparameters that must be set in the EutranNFreqRanShare MO to configure the PLMN information in theRAN sharing configuration of the neighboring frequencies for enabling inter-frequency blind handoverswhen there is no neighboring cells.

ParameterName


Setting Notes

Local cellID

EutranNFreqRanShare.LocalCel l Id Networkplan

Ensure that this parameter has beenset in a Cell MO.



ParameterName


Setting Notes


DownlinkEARFCN

EutranNFreqRanShare.DlEarfcn Networkplan(negotiationnotrequired)

This parameter specifies the DLEARFCN of the cells on theneighboring E-UTRAN frequency. Thisparameter references thecorresponding parameter in the CellMO on the peer eNodeB.

Add only the frequencies for blindhandovers triggered when there is noneighboring cells, and ensure thatEARFCN has been set in an EutranInterNFreq MO.

Mobilecountrycode

EutranNFreqRanShare.Mcc Networkplan(negotiationrequired)

This parameter specifies the MCC ofthe frequency for blind handoverstriggered when there is no neighboringcells.

This parameter references thecorresponding parameter in theeNodeB MO on the peer eNodeB.

Mobilenetworkcode

EutranNFreqRanShare.Mnc Networkplan(negotiationrequired)

This parameter specifies the MNC ofthe frequency for blind handoverstriggered when there is no neighboringcells.

This parameter references thecorresponding parameter in theeNodeB MO on the peer eNodeB.

7.2.5 Activation












Table 7-3 Coverage-based Inter-Frequency Handover





Handover Algo switch A list-type sheet is

recommended.



Mobile country code,Mobile network code,eNodeB identity, Cellidentity, DownlinkEARFCN, UplinkEARFCN indicator, UplinkEARFCN, Physical cellidentity, Tracking areacode, Cell name

A list-type sheet isrecommended.

EutranExternalCellPlmn User-defined sheet


Mobile country code,Mobile network code,eNodeB identity, Cellidentity, Share mobilecountry code, Sharemobile network code


EutranInterNFreq User-defined sheet

EutranInterNFreq isrecommended.

Local cell identity,Downlink EARFCN,Uplink EARFCN configureindicator, UplinkEARFCN, Inter frequencycell resel priorityconfigure indicator, Interfrequency cell reselpriority, EUTRANreselection time(s),Speed dependent reselparameter configuringindicator, Scaling factor oftreseleutra in mediummobility state, Scalingfactor of treseleutra inhigh mobility state,Measurementbandwidth(MHz),Frequency offset(dB),

Inter frequency highpriority threshold(2dB),Inter frequency lowerpriority threshold(2dB),Minimum required RXlevel(2dBm), PMAXconfigure indicator,PMAX(dBm), Neighborcell config, Presence






antenna port1, Inter-FreqHO trigger Event Type

EutranInterFreqNCell User-defined sheet

EutranInterFreqNCell isrecommended.

Local cell identity, Mobile

country code, Mobilenetwork code, eNodeBidentity, Cell identity, Cellindividual offset(dB), Celloffset(dB), No handoverindicator, No removeindicator, Blind handoverPriority, ANR flag, Localcell name, Neighbour cellname

A list-type sheet is

recommended.




NOTE:


2. Choose CME > LTE Application > Export Data > Export Base Station Bulk ConfigurationData (U2000 client mode), or choose LTE Application > Export Data > Export Base StationBulk Configuration Data (CME client mode), to export the eNodeB data stored on the CMEinto the customized summary data file.

3. In the summary data file, set the parameters in the MOs listed in Table 7-3 and close the file.4. Choose CME > LTE Application > Import Data > Import Base Station Bulk Configuration





















Using MML Commands

1. Run the MOD ENODEBALGOSWITCH command to enable coverage-based inter-frequencyhandover.

2. Run the following commands to add neighbor relationships with inter-frequency E-UTRANcells:

a. ADD EUTRANINTERNFREQ

b. (Optional) ADD EUTRANEXTERNALCELL, which is required when the inter-frequencyneighboring cell is under a different eNodeB from the local cell.

c. (Optional) ADD EUTRANEXTERNALCELLPLMN, which is used to configure the PLMNlist for an external E-UTRAN cell when the neighboring E-UTRAN cell works in RANsharing mode.

d. ADD EUTRANINTERFREQNCELL




//Activating coverage-based inter-frequency handover

MOD ENODEBALGOSWITCH: HoAlgoSwitch=InterFreqCoverHoSwitch-1;

//Adding inter-frequency neighboring E-UTRAN cells

ADD EUTRANINTERNFREQ: LocalCellId=0, DlEarfcn=2860,UlEarfcnCfgInd=NOT_CFG, CellReselPriorityCfgInd=NOT_CFG,

SpeedDependSPCfgInd=NOT_CFG, MeasBandWidth=MBW100, PmaxCfgInd=NOT_CFG,QqualMinCfgInd=NOT_CFG;

ADD EUTRANEXTERNALCELL: Mcc="460", Mnc="20", eNodeBId=123, CellId=1,DlEarfcn=2860, UlEarfcnCfgInd=NOT_CFG, PhyCellId=101, Tac=1;

ADD EUTRANEXTERNALCELLPLMN: Mcc="460", Mnc="20", eNodeBId=123, CellId=1,ShareMcc="460", ShareMnc="22";

ADD EUTRANINTERFREQNCELL: LocalCellId=0, Mcc="460", Mnc="20",eNodeBId=123, CellId=1;


This section uses A4-triggered inter-frequency handover as an example. The observation procedure is asfollows:

1. Trace messages over the Uu interface on the U2000 client after UEs access the network.Check the RRC_CONN_RECFG message. If the message contains measurementconfiguration of events A1 and A2 for a coverage-based inter-frequency handover, you caninfer that coverage-based inter-frequency handover has been activated.

2. Trace messages over the Uu interface while the UE is moving towards the cell edge. After theeNodeB receives an A2-related measurement report from the UE, check theRRC_CONN_RECFG message that contains the inter-frequency measurement configurationand A4-related measurement report information.

3. Trace messages over the Uu interface after the UE moves to the cell edge. Check theRRC_CONN_RECFG message, which is a handover command, after the eNodeB receives an A4-related measurement report from the UE. If the message contains target cell accessinformation, you can infer that coverage-based inter-frequency handover has been triggered.

7.2.7 Deactivation



Table 7-4 Parameters related to coverage-based inter-frequency handovers




Clear the InterFreqCoverHoSwitch check box.


















Using MML Commands

To deactivate coverage-based inter-frequency handover, disable its algorithm by running the MODENODEBALGOSWITCH command.


//Deactivating coverage-based inter-frequency handover

MOD ENODEBALGOSWITCH: HoAlgoSwitch=InterFreqCoverHoSwitch-0;


Inter-frequency handovers are intended to ensure service continuity when users move around. How wellthese handovers serve this purpose reflects their performance. After activating coverage-based inter-frequency handover, check the following counters to monitor and evaluate handover performance:

Success rate of X2 and S1 handovers. The interface-specific statistics helps locating thehandover failure cause. The related counters are: Intra-eNB Inter-frequency Handover Out Success Rate

Inter-eNB Inter-frequency Handover Out Success Rate Blind Handover Out Success Rate

Abnormal Release Rate indicating the service drop rate

If the handover success rate is low and the service drop rate is high, the performance of coverage-basedinter-frequency handover is poor. In this situation, check the related parameter settings and networkcoverage.

Table 7-5 lists the counters related to coverage-based inter-frequency and inter-mode handover.

Table 7-5 Counters related to coverage-based inter-frequency and inter-mode handover

Counter ID Counter Name Counter Description

1526728933 L.HHO.InterFreq.Coverage.PrepAttOut Number of coverage-basedinter-frequency handoverpreparation attempts

1526728934 L.HHO.InterFreq.Coverage.ExecAttOut Number of Coverage-basedInter-Frequency HandoverExecution Attempts

1526728935 L.HHO.InterFreq.Coverage.ExecSuccOut Number of SuccessfulCoverage-based Inter-Frequency Handovers

1526729612 L.HHO.InterFddTdd.Coverage.PrepAttOut Number of coverage-basedinter-duplex-mode

handover preparationattempts

1526729613 L.HHO.InterFddTdd.Coverage.ExecAttOut Number of coverage-basedinter-duplex-modehandover executionattempts

1526729614 L.HHO.InterFddTdd.Coverage.ExecSuccOut Number of successfulcoverage-based inter-










duplex-mode handoverexecutions


Inter-Frequency Handover Parameters

Inter-frequency handover parameters are contained in the InterFreqHoGroup MO.

ParameterName


Setting Notes

Local cell ID InterFreqHoGroup.LocalCel l Id Networkplan(negotiation notrequired)

Ensure that this parameter has beenset in a Cell MO based on thenetwork plan.

Interfreqhandovergroup ID

InterFreqHoGroup.InterFreqHoGrou

p Id Networkplan(negotiation notrequired)

This parameter specifies the ID ofthe parameter group related to inter-frequency handovers.

If you want to set different inter-frequency handover parameters forservices with a specific QCI, youmust create a parameter group, andreference the parameter group ID tothe corresponding QCI.

Interfreq A1A2hysteresis

InterFreqHoGroup.InterFreqHoA1A2 Hyst

Networkplan(negotiat

ion notrequired)

This parameter specifies thehysteresis for events A1 and A2 forinter-frequency measurement. A

larger value causes a lowerprobability of triggering event A1 or A2 for inter-frequency measurement. A smaller value causes a higherprobability.

It is recommended that the defaultvalue be used.

Interfreq A1A2 timeto trigger

InterFreqHoGroup.InterFreqHoA1A2 TimeToTrig

Networkplan(negotiation not

required)

This parameter specifies the time-to-trigger for events A1 and A2 for inter-frequency measurement. This time-to-trigger effectively reduces the

number of inter-frequencymeasurements to be started,preventing unnecessary inter-frequency measurement. Theaverage number of inter-frequencymeasurements to be started has anegative correlation with the time-to-trigger. At the same time, anexcessively large value of the time-






ParameterName


Setting Notes

to-trigger results in a high risk ofservice drops.



InterFreqHoGroup.InterFreqHoA1Th dRsrp

Networkplan(negotiation notrequired)

This parameter specifies the RSRPthreshold for event A1 associatedwith inter-frequency measurement. Alarger value causes a lowerprobability of triggering event A1. Asmaller value causes a higherprobability.

The value of this parameter must be(usually 4 dB) greater than or equalto the sum of the value ofInterFreqHoGroup.InterFreqHoA2T hdRsrp and RSRP threshold offsetfor event A2 for inter-frequencymeasurement (set in theCnOperatorHoCfg MO).


InterFreqHoGroup.InterFreqHoA1Th dRsrq


This parameter specifies the RSRQthreshold for event A1 for inter-frequency measurement. A largervalue causes a lower probability oftriggering event A1. A smaller valuecauses a higher probability.

The value of this parameter must be(usually 2 dB) greater than or equalto the sum of the value ofInterFreqHoGroup.InterFreqHoA2T hdRsrq .




This parameter specifies the RSRPthreshold for event A2 for inter-frequency measurement. A largervalue causes a lower probability oftriggering event A2. A smaller valuecauses a higher probability.

Set this parameter based on theactual conditions. Usually, set thisparameter to the RSRP in the areawhere the UE throughput in theserving cell is similar to that in theneighboring cell.



Networkplan(negotiat

This parameter specifies the RSRQthreshold for event A2 for inter-frequency measurement. A larger



ParameterName


Setting Notes

ion notrequired)

value causes a lower probability oftriggering event A2. A smaller valuecauses a higher probability.

Set this parameter based on theactual conditions. Usually, set thisparameter to the RSRQ in the areawhere the UE throughput in theserving cell is similar to that in theneighboring cell.

Interfreqhandoverhysteresis

InterFreqHoGroup.InterFreqHoA4Hy st


This parameter specifies thehysteresis for event A4. A largervalue causes a lower probability oftriggering event A4. A smaller valuecauses a higher probability.


CoverageBasedInterfreqRSRPthreshold



This parameter specifies the RSRPthreshold for event A4 in a coverage-based, UL-quality-based, ordistance-based handover, or in aSPID-based handover to theHPLMN. A larger value causes alower probability of triggering event A4. A smaller value causes a higherprobability.

The value of this parameter must begreater than the sum of the peer-endRSRP threshold for event A2 forinter-frequency measurement (set inthe InterFreqHoGroup MO at thepeer eNodeB) and the RSRPthreshold offset for event A2 for inter-frequency measurement for thehigher-priority RAT(set in theCnOperatorHoCfg MO at the peereNodeB).

CoverageBased InterfrqRSRQthreshold



This parameter specifies the RSRQthreshold for event A4 in a coverage-based, UL-quality-based, ordistance-based handover, or in aSPID-based handover to theHPLMN. A larger value causes alower probability of triggering event A4. A smaller value causes a higherprobability.



ParameterName


Setting Notes

The value of this parameter must begreater than or equal to the peer-endRSRQ threshold for event A2 for

inter-frequency measurement set atthe peer eNodeB (set in theInterFreqHoGroup MO at the peereNodeB).

InterfreqHandOverTime toTrigger

InterFreqHoGroup.InterFreqHoA4Ti meToTrig


This parameter specifies the time-to-trigger for event A4. A larger valuecauses a lower probability ofhandover to inter-frequencyneighboring E-UTRAN cells and asmaller average number ofhandovers, but a higher risk ofservice drops. A smaller valuecauses the opposite effect.

If both coverage-based inter-frequency handovers and coverage-based inter-RAT handovers areenabled, you are advised to set thetime-to-trigger for the inter-frequencyhandover event to be smaller thanthat for the inter-RAT handover eventso that intra-RAT is preferentiallyperformed. This helps increase thepossibility of inter-frequencyhandovers.

Interfreq A3offset InterFreqHoGroup.InterFreqHoA3Off

set Networkplan(negotiation notrequired)

This parameter specifies the offsetfor event A3 associated with inter-frequency handover. It determinesthe border between the serving celland the neighboring cell. If theparameter is set to a large value, aninter-frequency handover isperformed only when the signalquality of the neighboring cell issignificantly better than that of theserving cell and other triggeringconditions are met.

It is recommended that you adjustthe parameter value based on theapplication scenario. Increase theparameter value if premature inter-frequency handovers occur.Decrease the parameter value ifdelayed inter-frequency handoversoccur.



ParameterName


Setting Notes

A3 basedinterfreq A1RSRPthreshold

InterFreqHoGroup.A3InterFreqHoA1 ThdRsrp


This parameter specifies the RSRPthreshold for event A1 associatedwith event-A3-triggered inter-frequency handover. A relativelylarge value results in a lowprobability of stopping inter-frequency measurements, whereas arelatively small value results in a highprobability.

It is recommended that the value ofthis parameter be 4 dB greater thanor equal to the sum of the value ofInterFreqHoGroup.A3InterFreqHo A2ThdRsrp and RSRP thresholdoffset for event A2 for inter-frequencymeasurement (set in theCnOperatorHoCfg MO).

A3 basedInterfreq A2RSRPthreshold

InterFreqHoGroup.A3InterFreqHoA2 ThdRsrp


This parameter specifies the RSRPthreshold for event A2 associatedwith event-A3-triggered inter-frequency handover. A relativelysmall value results in a lowprobability of starting inter-frequencymeasurements, whereas a relativelylarge value results in a highprobability.

Set this parameter based on actual

conditions to ensure that event-A3-triggered inter-frequency handoverscan occur timely.

Cell Individual Offset for Inter-Frequency Neighboring Cells

The following table provides the parameter that must be set in the EutranInterFreqNCell MO to adjustcell individual offset for the inter-frequency neighboring cells

ParameterName


Setting Notes

Cellindividual

offset

EutranInterFreqNCell.Cell IndividualOffset Networkplan


This parameter affects theprobability of reporting inter-

frequency measurementevents. A larger valueindicates a higher probability.

If there are multiple target cellsfor the inter-frequencyhandover and relatedhandover parameters need tobe optimized, you can



ParameterName


Setting Notes

decrease this parameter valuefor a neighboring cell to reducethe possibility of the handover

to the neighboring cell, or youcan increase this parametervalue for a neighboring cell toraise the possibility of thehandover to the neighboringcell.

Intra-RAT Inter-Frequency Handover Parameters

Intra-RAT handover parameters are contained in the IntraRatHoComm MO.

ParameterName


Setting Notes

Max reportcell number IntraRatHoComm.IntraRatHoMaxRprtCel l

Networkplan(negotiationnotrequired)

This parameter specifiesthe maximum number ofcells to be included ineach intra-frequency orinter-frequencymeasurement reportafter the correspondingevent is triggered. Setthis parameter to a largervalue if the eNodeBrequires more candidatecells to make a handoverdecision. An excessivelylarge value, however,

causes a waste of airinterface resources.

It is recommended thatthe default value beused.

Measurementreportamount

IntraRatHoComm.In traRatHoRprtAmount Networkplan(negotiationnotrequired)

This parameter specifiesthe number of intra-frequency or inter-frequency periodicalmeasurement reports tobe sent after the

corresponding event istriggered. Set thisparameter to a largervalue if the eNodeBrequires moremeasurement reports tomake a handoverdecision. An excessivelylarge parameter value,



ParameterName


Setting Notes

however, causes awaste of air interfaceresources.


Measurement A4 reportquantity

IntraRatHoComm.InterFreqHoA4RprtQuan Networkplan(negotiationnotrequired)

This parameter specifiesthe reporting quantity tobe included in themeasurement reportsafter event A4 istriggered. It can be eitherthe same as thetriggering quantity forevent A4 for inter-

frequency measurementor both RSRP andRSRQ. That is, themeasurement resultscan be RSRP-based,RSRQ-based, or both in A4-related measurementreports.

It is recommended thatthe default value be usedif the traffic load of LTEcells is not stable.

Interfreqmeasurementreport interval

IntraRatHoComm.InterFreqHoRprtInterval Networkplan(negotiationnotrequired)

This parameter specifiesthe interval betweenevery two reports thatare triggered by event A4. A smaller valuecauses moremeasurement reportsand greater consumptionof air interfaceresources, but a higherprobability of triggeringhandovers. Anexcessively largeparameter value,however, causes a longdelay in retries and a lowhandover success rate.




ParameterName


Setting Notes

A1A2Measurementtrig quantity

IntraRatHoComm.InterFreqHoA1A2TrigQuan Networkplan(negotiationnotrequired)

This parameter specifiesthe triggering quantity forinter-frequencymeasurement events A1and A2. The parametercan be either RSRP orRSRQ. RSRQ-basedmeasurement resultsreflect signal quality inreal time, whereasRSRP-basedmeasurement results arestable with little signalfluctuation.

It is recommended thatthe default value be usedif the traffic load of LTEcells is not stable.

When event A3 is used to trigger coverage-based inter-frequency handovers, the reconfiguration of otherparameters is the same as those in coverage-based intra-frequency handovers. For details, see 7.1.9Parameter Optimization.

Threshold Parameters Related to Coverage-based Handovers

Coverage-based inter-frequency blind handover thresholds are contained in the CellHoParaCfg MO.

Parameter Name Parameter ID DataSource

Setting Notes

BlindHOA1A2ThdRsrp CellHoParaCfg.Bl indHOA1A2ThdRsrp Networkplan(negotiationnotrequired)

This parameterspecifies the RSRPthreshold for events A1and A2 that are usedfor coverage-basedinter-frequency andinter-RAT blindhandovers.

Set this parameterbased on the actualcoverage conditions to

ensure that servicedrops do not occurwithin correspondingareas.

BlindHOA1A2ThdRsrq CellHoParaCfg.Bl indHoA1A2ThdRsrq Networkplan(negotiationnotrequired)

This parameterspecifies the RSRQthreshold for events A1and A2 that are usedfor coverage-based









Parameter Name Parameter ID DataSource

Setting Notes

inter-frequency andinter-RAT blindhandovers.

Set this parameterbased on the actualcoverage conditions toensure that servicedrops do not occurwithin correspondingareas.


Fault description:

An event A4 measurement report may not be submitted when a UE moving toward the cell edgeexperiences a call drop.

Fault handling

Perform the following steps to determine whether the handover parameters are set correctly:

1. Check the messages over the S1 interface and locate the IE Cause in theS1AP_UE_CONTEXT_REL_REQ message.

If the value of this IE is radioNetwork:radio-connection-with-ue-lost, go to 2.

If the value of this IE is not radioNetwork:radio-connection-with-ue-lost, the handoverparameters are set correctly. Contact Huawei technical support engineers.

2. Check the messages over the Uu interface for A4 measurement reports in RRC_MEAS_RPRTmessages prior to RRC_CONN_REL messages.

If such reports cannot be found, this problem is due to inappropriate settings of handoverparameters. Go to 3.

If such reports can be found, contact Huawei engineers.3. Run the MOD INTERFREQHOGROUP command to reconfigure the following parameters:

Interfreq A2 RSRP threshold

Interfreq A2 RSRQ threshold

Interfreq handover hysteresis

CoverageBased Interfreq RSRP threshold

CoverageBased Interfreq RSRQ threshold


7.3.1 When to Use Service-based Inter-Frequency Handover

You can enable service-based inter-frequency handover if service differentiation is required byassigning services of different priorities to different frequencies. For example, services with a

QCI of 1 can be assigned to a narrow-bandwidth frequency and services with other QCIs be

assigned to other wide-bandwidth frequencies. Note that service-based inter-frequency handovercan be enabled on multiple E-UTRAN frequencies, but their QCI-based policy configurations

must be the same.





















Before deploying service-based inter-frequency handover, collect information about the normal

inter-site spacing and the service that the RF signals of the cell exerting overshoot coverage can

travel to properly set the TA threshold.

7.3.3 Requirements


None


None

License

None







Required Data

For details about the required data, see 7.2.4 Data Preparation.


Service-based inter-frequency handover can be enabled only after coverage-based inter-frequencyhandover is enabled. This section describes the required parameters except those for coverage-basedinter-frequency handover. For details on the required parameters for coverage-based inter-frequencyhandover, see the "Scenario-specific Data" part in 7.2.4 Data Preparation.

The following table describes the parameter that must be set in the ENodeBAlgoSwitch MO to configureservice-based inter-frequency handover.

Parameter

Name


Setting Notes

Handover Algoswitch

ENodeBAlgoSwitch.HoAl

goSwi tch Networkplan(negotiation not

To enable service-based inter-frequency handover,select theServiceBasedInterFreqHoSwitch(ServiceBasedInterFreqHoSwitch) check box under this parameter.
























Parameter

Name


Setting Notes

required)

The following table describes the parameters that must be set in the ServiceIfHoCfgGroup MO toconfigure a service-based inter-frequency handover policy.

ParameterName


Setting Notes

CNOperatorID

ServiceIfHoCfgGroup.CnOperatorId Networkplan(negotiationnotrequired)

This parameter specifiesthe index of the operator.Ensure that this parameterhas been set in aCnOperator MO.

Service-

basedinter-Freqhandoverpolicygroup ID

ServiceIfHoCfgGroup.ServiceIfHoCfgGroupId Network


This parameter specifies

the ID of the service-basedinter-frequency handoverpolicy group.

This parameter can bereferenced by serviceswith a specific QCI.

Inter-Freqhandoverstate

ServiceIfHoCfgGroup.InterFreqHoState Networkplan(negotiationnotrequired)

This parameter specifieswhether to allow service-based inter-frequencyhandovers to a specificfrequency.

The following table describes the parameters that must be set in the ServiceIfDlEarfcnGrp MO toconfigure a group of downlink EARFCNs to service-based inter-frequency handover policy group.

ParameterName


CNOperatorID

ServiceIfDlEarfcnGrp.CnOperatorId

Network plan(negotiation notrequired)

This parameter indicates the ID of theoperator.

This parameter references thecorresponding parameter defined inthe CnOperator MO.

ServiceInterfreqHo PolicyGroup Id

ServiceIfDlEarfcnGrp. ServiceIfHoCfgGroupId


This parameter specifies the ID of theservice-based inter-frequencyhandover policy group.

This parameter configured the indexfor QCI.

DownlinkEARFCNIndex

ServiceIfDlEarfcnGrp. DlEarfcnIndex


This parameter indicates the index ofa downlink EARFCN in a downlink



ParameterName


EARFCN group for service-basedinter-frequency handover.

Only the value with DlEarfcnIndex set to 0 in the downlink EARFCNgroup is valid for LTE FDD cells. Allvalues of this parameter are valid andhave the same priority for LTE TDDcells.

DownlinkEARFCN

ServiceIfDlEarfcnGrp. DlEarfcn


This parameter indicates a downlinkEARFCN for service-based inter-frequency handover.

Only the value with DlEarfcn set to 0in the downlink EARFCN group isvalid for LTE FDD cells. All values ofthis parameter are valid and have thesame priority for LTE TDD cells.

The following tables describe the parameter that must be set to configure inter-frequency handover policygroups for services with standard or extended QCIs.

The following table describes the parameters that must be set in the CnOperatorStandardQci MO toconfigure inter-frequency handover policy groups for services with standard QCIs.

Parameter

Name


Setting Notes

CN

Operator ID

CnOperatorStandardQci.CnOperatorId Network


This parameter specifies the index of

the operator. Ensure that thisparameter has been set in aCnOperator MO.

QoSClassIndication

CnOperatorStandardQci.Qci Networkplan(negotiation notrequired)

This parameter specifies the index ofthe standard QCI for which theparameter group is configured.

Service-basedinter-

Freqhandover policygroup ID

CnOperatorStandardQci.ServiceIfHoC fgGroupId

Networkplan(negotiati

on notrequired)


Set this parameter to an ID that isconfigured inServiceIfHoCfgGroup.ServiceIfHoCf gGroupId .

The following table describes the parameters that must be set in the CnOperatorExtendedQci MO toconfigure inter-frequency handover policy groups for services with extended QCIs.



Parameter

Name


Setting Notes

CNOperator ID

CnOperatorExtendedQci.CnOperatorI

d Networkplan(negotiation notrequired)

This parameter specifies the index ofthe operator. Ensure that thisparameter has been set in aCnOperator MO.

CNOperatorextended QCI

CnOperatorExtendedQci.ExtendedQci Networkplan(negotiation notrequired)

This parameter specifies the index ofthe extended QCI for which theparameter group is configured.

Service-basedinter-Freq

handover policygroup ID

CnOperatorExtendedQci.ServiceIfHoC fgGroupId

Networkplan(negotiation not

required)


Set this parameter to an ID that isconfigured inServiceIfHoCfgGroup.ServiceIfHoCf gGroupId .

The following table describes the parameters that must be set in the CellStandardQci MO to configurepriority for standard cell QCI.

ParameterName


QCI PriorityForHandover

CellStandardQci.QciPriori tyForHo Network plan(negotiation notrequired)

This parameter specifiespriority mapping the QCI.

7.3.5 Activation







Table 7-6 Service-based Inter-Frequency Handover









ENodeBAlgoSwitch is

recommended.

Handover Algo switch A list-typesheet isrecommended.

ServiceIfHoCfgGroup User-defined sheet

ServiceIfHoCfgGroup isrecommended.

CN Operator ID, Service-basedinter-Freq handover policy groupID, Inter-Freq handover state,Downlink EARFCN








Mobile country code, Mobilenetwork code, eNodeB identity,Cell identity, Share mobilecountry code, Share mobilenetwork code




Local cell identity, DownlinkEARFCN, Uplink EARFCNconfigure indicator, UplinkEARFCN, Inter frequency cellresel priority configure indicator,Inter frequency cell resel priority,EUTRAN reselection time(s),Speed dependent resel

parameter configuring indicator,Scaling factor of treseleutra inmedium mobility state, Scalingfactor of treseleutra in highmobility state, Measurementbandwidth(MHz), Frequencyoffset(dB), Inter frequency highpriority threshold(2dB), Interfrequency lower prioritythreshold(2dB), Minimumrequired RX level(2dBm), PMAXconfigure indicator, PMAX(dBm),Neighbor cell config, Presence

antenna port1, Inter-Freq HOtrigger Event Type




Local cell identity, Mobile countrycode, Mobile network code,eNodeB identity, Cell identity,Cell individual offset(dB), Celloffset(dB), No handover indicator,No remove indicator, Blindhandover Priority, ANR flag,






Local cell name, Neighbour cellname




NOTE:
























Using MML Commands

1. Run the MOD ENODEBALGOSWITCH command to enable service-based inter-frequencyhandover.

2. Run the MOD SERVICEIFHOCFGGROUP command to configure a service-based inter-frequency handover policy group.

3. Run the following commands to add neighbor relationships with inter-frequency E-UTRAN

cells:a. ADD EUTRANINTERNFREQ b. (Optional) ADD EUTRANEXTERNALCELL, which is required when the inter-frequency

neighboring cell is under a different eNodeB from the local cell.c. (Optional) ADD EUTRANEXTERNALCELLPLMN, which is used to configure the PLMN


d. ADD EUTRANINTERFREQNCELL 4. Run the following command to modify service settings:



a. To modify the settings of a standardized QCI for an operator, run the MODCNOPERATORSTANDARDQCI command.

b. To add a Huawei-defined extended QCI for an operator, run the ADDCNOPERATOREXTENDEDQCI command.

5. Run the ADD SERVICEIFDLEARFCNGRP command to add target EARFCNs for specifiedservices.


//Activating service-based inter-frequency handover

MOD ENODEBALGOSWITCH: HoAlgoSwitch=ServiceBasedInterFreqHoSwitch-1;

MOD SERVICEIFHOCFGGROUP: CnOperatorId=0, ServiceIfHoCfgGroupId=0,InterFreqHoState=PERMIT_HO, DlEarfcn=2860;


ADD EUTRANINTERNFREQ: LocalCellId=0, DlEarfcn=2860,UlEarfcnCfgInd=NOT_CFG, CellReselPriorityCfgInd=NOT_CFG,SpeedDependSPCfgInd=NOT_CFG, MeasBandWidth=MBW100, PmaxCfgInd=NOT_CFG,QqualMinCfgInd=NOT_CFG;




//Configuring services with standard QCI and target EARFCNs

MOD CNOPERATORSTANDARDQCI: CnOperatorId=0, Qci=QCI9,ServiceIrHoCfgGroupId=0;

ADD SERVICEIFDLEARFCNGRP: CnOperatorId=0, ServiceIfHoCfgGroupId=9,

DlEarfcnIndex=0, DlEarfcn=38100;



1. Trace messages over the S1 interface after a UE accesses the network at the center of a cellin the 2600 MHz band and sets up a handover-enabled dedicated bearer with a QCI of 2.Check the S1AP_ERAB_SETUP_REQ message. If the message contains dedicated-bearerconfiguration, you can infer that service-based inter-frequency handover has been activated.

2. Trace messages over the Uu interface on the U2000 client. Check the RRC_CONN_RECFGmessage that contains the A4-related inter-frequency measurement configuration for service-based handover.

3. Trace messages over the Uu interface on the U2000 client again. Check theRRC_CONN_RECFG message, which is the handover command sent from the eNodeB after

the eNodeB receives an A4-related inter-frequency measurement report from the UE for aservice-based handover. If the message contains target cell access information, you can inferthat service-based inter-frequency handover has been triggered.

7.3.7 Deactivation


Batch reconfiguration using the CME is the recommended method to deactivate a feature on eNodeBs.This method reconfigures all data, except neighbor relationships, for multiple eNodeBs in a single









procedure. The procedure for feature deactivation is similar to that for feature activation described inUsing the CME to Perform Batch Configuration for Existing eNodeBs. In the procedure, modify relatedparameters described below.

Table 7-7 Parameters related to service-based inter-frequency handover




Clear theServiceBasedInterFreqHoSwitch check box.



Using MML Commands

To deactivate service-based inter-frequency handover, disable its algorithm by running the MODENODEBALGOSWITCH command.


//Deactivating service-based inter-frequency handover

MOD ENODEBALGOSWITCH: HoAlgoSwitch=ServiceBasedInterFreqHoSwitch-0;


The handover success rate and service drop rate used for monitoring the performance of service-basedinter-frequency handover are the same as those for monitoring the performance of coverage-based inter-frequency handover. For details, see 7.2.8 Performance Monitoring.

Table 7-8 lists the counters related to service-based inter-frequency and inter-mode handover.

Table 7-8 Counters related to service-based inter-frequency and inter-mode handover


1526729479 L.HHO.InterFreq.Service.PrepAttOut Number of service-based inter-frequency handover preparationattempts

1526729480 L.HHO.InterFreq.Service.ExecAttOut Number of Service-based Inter-Frequency Handover Execution Attempts

1526729481 L.HHO.InterFreq.Service.ExecSuccOut Number of Successful Service-basedInter-Frequency Handover Executions

1526730002 L.HHO.InterFddTdd.Service.PrepAttOut Number of service-based inter-duplex-mode handover preparation attempts

1526730003 L.HHO.InterFddTdd.Service.ExecAttOut Number of service-based inter-duplex-mode handover execution attempts





















1526730004 L.HHO.InterFddTdd.Service.ExecSuccOut Number of successful service-basedinter-duplex-mode handoverexecutions


The reconfiguration of parameters that are not involved in this section is the same as the reconfigurationof parameters for coverage-based inter-frequency handovers. For details, see 7.2.9 ParameterOptimization.



Parameter Name


Setting Notes

Local cell

ID

InterFreqHoGroup.LocalCel l Id Network


Ensure that this

parameter hasbeen set in a Cell MO based on thenetwork plan.


InterFreqHoGroup.InterFreqLoadBasedHoA4ThdRsr p


This parameterspecifies theRSRP thresholdfor event A4 forload-based,frequency-priority-based, andservice-basedinter-frequency

handovers. Alarger valuecauses a lowerprobability oftriggering event A4. A smallervalue causes ahigher probability.

The value of thisparameter must begreater than thesum of the peer-

end RSRPthreshold for event A2 for inter-frequencymeasurement (setin theInterFreqHoGroup MO at the peereNodeB) and the












Parameter Name


Setting Notes

RSRP thresholdoffset for event A2for inter-frequency

measurement (setin theCnOperatorHoCfg MO at the peereNodeB).

LoadBasedInterfrqRSRQthreshold

InterFreqHoGroup.InterFreqLoadBasedHoA4ThdRsr q


This parameterspecifies theRSRQ thresholdfor event A4 forload-based,frequency-priority-based, andservice-based

inter-frequencyhandovers. Alarger valuecauses a lowerprobability oftriggering event A4. A smallervalue causes ahigher probability.

The value of thisparameter must begreater than or

equal to the peer-end RSRQthreshold for event A2 for inter-frequencymeasurement setat the peereNodeB (set in theInterFreqHoGroup MO at the peereNodeB).



ParameterName


Setting Notes

FreqPriorloadBased A4Measurement

IntraRatHoComm.InterFreqHoA4TrigQuan Networkplan(negotiation

This parameter specifiesthe event A4 triggeringquantity for inter-frequencyhandovers other than



ParameterName


Setting Notes

triggerquantity

notrequired)

coverage-based inter-frequency handovers. Thequantity can be either

RSRP or RSRQ, or both.The measured RSRPvalues are stable, slightlyvarying with the load, andtherefore there is littlesignal fluctuation. Themeasured RSRQ valuesvary with the load and arelikely to reflect the signalquality of the cell in realtime.

It is recommended that thedefault value be used if thetraffic load of LTE cells isnot stable.


Fault description

A UE with a service of QCIx may not be handed over to a cell working at frequency F1 after the handoverpolicy has been set to enable services with QCIx to be handed over to a cell working at frequency F1.

Fault handling


1. Check the messages over the S1 interface and locate the e-RABlevelQoSParameters IE in theS1AP_INITIAL_CONTEXT_SETUP_REQ message and the S1AP_ERAB_SETUP_REQmessage (which may not exist).

If QCIx is not contained in the e-RABlevelQoSParameters IE, ignore this fault andperform the test again after verifying that the UE has set up a service with QCIx.

If QCIx is contained in the e-RABlevelQoSParameters IE, check whether the UE has setup a service which is not allowed to be handed over to a cell working at F1 because of itsQCI. If yes, perform the test again after the UE has stopped this service. If no, go to step 2.

2. Check the messages over the Uu interface for A4 measurement reports in RRC_MEAS_RPRTmessages.


If such reports can be found, contact Huawei technical support engineers.3. Run the MOD INTERFREQHOGROUP command to reconfigure the following parameters:

















7.4.1 When to Use Distance-based Inter-Frequency Handover

If high bands and low bands are used to cover separate areas that border each other, RF signals

from a high-band cell may be able to travel a long distance (for example, three times the inter-

site spacing) and cause severe overshoot coverage to low-band cells. If the low-band cells are not

configured as neighboring cells of the high-band cell, inter-frequency measurements cannot betriggered in time and call drops will occur. To reduce the probability of such call drops, you can

enable distance-based inter-frequency handover.


Before deploying distance-based inter-frequency handover, collect information about the distance that theRF signals of the cell exerting overshoot coverage based on the inter-eNodeB distance on the livenetwork. This distance is the criterion for the distance-based inter-frequency handover threshold.

7.4.3 Requirements


None


None

License

None


This section describes the data that you need to collect for setting parameters. Required data is data thatyou must collect for all scenarios. Collect scenario-specific data when necessary for a specific feature

deployment scenario.





Required Data



Distance-based inter-frequency handover can be enabled only after coverage-based inter-frequencyhandover is enabled. This section describes the required parameters except those for coverage-basedinter-frequency handover. For details on the required parameters for coverage-based inter-frequencyhandover, see the "Scenario-specific Data" part in 7.2.4 Data Preparation.

To enable distance-based inter-frequency handovers, the corresponding switch must be turned on andthe measurement object type must be set to EUTRAN.



























The following table describes the parameters that must be set in the CellAlgoSwitch MO to enabledistance-based inter-frequency handovers.

ParameterName


Setting Notes

Local cell ID CellAlgoSwitch.LocalCel l Id Network


Ensure that this parameter has

been set in a Cell MO.

Distance-basedHandoverSwitch

CellAlgoSwitch.DistBasedHoSwi tch Networkplan(negotiationnotrequired)

This parameter specifies whetherto enable distance-basedhandovers. If this switch is turnedon, distance-based handovers areallowed. If this switch is turnedoff, distance-based handovers toany cells are prohibited.

The following table describes the parameters that must be set in the DistBasedHO MO to set themeasurement object type.

ParameterName


Setting Notes

Local cell ID DistBasedHO.LocalCel l Id Networkplan(negotiationnotrequired)

Ensure that this parameter hasbeen set in a Cell MO.

Distance-based

MeasurementObject Type

DistBasedHO.DistBasedMeasObjType Networkplan


This parameter specifies themeasurement object type for

distance-based handovers.

If this parameter is set toEUTRAN, distanced-basedhandovers to inter-frequencyneighboring cells are allowed.

7.4.5 Activation












Table 7-9 Distance-based Inter-Frequency Handover



CellAlgoSwitch User-defined sheet

CellAlgoSwitch isrecommended.

Distance-based Handover Switch A list-typesheet isrecommended.

DistBaseDHO User-defined sheet

DistBasedHO isrecommended.

Local cell identity, Distance-based Measurement ObjectType, Distance-based HandoverThreshold











EutranInterNFreq is

recommended.

Local cell identity, DownlinkEARFCN, Uplink EARFCNconfigure indicator, UplinkEARFCN, Inter frequency cellresel priority configure indicator,Inter frequency cell resel priority,EUTRAN reselection time(s),Speed dependent reselparameter configuring indicator,Scaling factor of treseleutra inmedium mobility state, Scalingfactor of treseleutra in highmobility state, Measurementbandwidth(MHz), Frequencyoffset(dB), Inter frequency highpriority threshold(2dB), Interfrequency lower priority

threshold(2dB), Minimumrequired RX level(2dBm), PMAXconfigure indicator, PMAX(dBm),Neighbor cell config, Presenceantenna port1, Inter-Freq HOtrigger Event Type







EutranInterFreqNCell is

recommended.

Local cell identity, Mobile countrycode, Mobile network code,eNodeB identity, Cell identity,Cell individual offset(dB), Celloffset(dB), No handover indicator,No remove indicator, Blindhandover Priority, ANR flag,Local cell name, Neighbour cellname




1. Choose CME > Advanced > Customize Summary Data File (U2000 client mode), or choose

Advanced > Customize Summary Data File (CME client mode), to customize a summarydata file for batch reconfiguration.

NOTE:



3. In the summary data file, set the parameters in the MOs listed in Table 7-9 and close the file.

4. Choose CME > LTE Application > Import Data > Import Base Station Bulk ConfigurationData (U2000 client mode), or choose LTE Application > Import Data > Import Base StationBulk Configuration Data (CME client mode), to import the summary data file into the CME.




1. In the planned data area, click Base Station in the upper left corner of the configuration

window.2. In area 1 shown in Figure 7-4, select the eNodeB to which the MOs belong.















Using MML Commands

1. Run the MOD CELLALGOSWITCH command to turn on the switch for distance-basedhandover.

2. Run the MOD DISTBASEDHO command to enable the measurement for distance-based inter-frequency handover.

3. Run the following commands to add neighbor relationships with inter-frequency E-UTRAN

cells:a. ADD EUTRANINTERNFREQ b. (Optional) ADD EUTRANEXTERNALCELL, which is required when the inter-frequency

neighboring cell is under a different eNodeB from the local cell.c. (Optional) ADD EUTRANEXTERNALCELLPLMN, which is used to configure the PLMN






//Activating distance-based handover

MOD CELLALGOSWITCH: LocalCellId=0, DistBasedHoSwitch=ON;

MOD DISTBASEDHO: LocalCellId=0, DistBasedMeasObjType=EUTRAN-1;

//Adding inter-frequency neighboring E-UTRAN cellsADD EUTRANINTERNFREQ: LocalCellId=0, DlEarfcn=2860,

UlEarfcnCfgInd=NOT_CFG, CellReselPriorityCfgInd=NOT_CFG,SpeedDependSPCfgInd=NOT_CFG, MeasBandWidth=MBW100, PmaxCfgInd=NOT_CFG,QqualMinCfgInd=NOT_CFG;



ADD EUTRANINTERFREQNCELL: LocalCellId=0, Mcc="460", Mnc="20",

eNodeBId=123, CellId=1;



1. Trace messages over the Uu interface on the U2000 client after a UE accesses the network atthe center of a cell in the 2600 MHz band. Move the UE toward the cell edge. During themovement, inter-frequency measurements are not triggered for a coverage-based handoverdue to overshoot coverage, but the threshold for distance-based inter-frequency handover isreached. Check the RRC_CONN_RECFG message. If the message contains measurementconfiguration for a distance-based inter-frequency handover, you can infer that distance-basedinter-frequency handover has been activated.

2. Trace messages over the Uu interface on the U2000 client again. Check theRRC_CONN_RECFG message, which is the handover command sent from the eNodeB afterthe eNodeB receives an A4-related inter-frequency measurement report from the UE for a

distance-based handover. If the message contains target cell access information, you can inferthat distance-based inter-frequency handover has been triggered.

7.4.7 Deactivation



Table 7-10 Parameters related to distance-based inter-frequency handover



CellAlgoSwitch CellAlgoSwitch Distance-based HandoverSwitch

Set the switch to OFF(Off).














Using MML Commands

To deactivate the measurement for distance-based inter-frequency handover, disable its algorithm byrunning the MOD DISTBASEDHO command.


//Deactivating the measurement for distance-based inter-frequency handover

MOD DISTBASEDHO: LocalCellId=0, DistBasedMeasObjType=EUTRAN-0;


The handover success rate and service drop rate used for monitoring the performance of distance-basedinter-frequency handover are the same as those for monitoring the performance of coverage-based inter-frequency handover. For details, see 7.2.8 Performance Monitoring.

Table 7-11 lists the counters related to distance-based inter-frequency and inter-mode handover.

Table 7-11 Counters related to distance-based inter-frequency and inter-mode handover


1526730010 L.HHO.InterFreq.Distance.PrepAttOut Number of distance-based inter-frequency handover preparationattempts

1526730012 L.HHO.InterFreq.Distance.ExecAttOut Number of distance-based inter-frequency handover executionattempts

1526730014 L.HHO.InterFreq.Distance.ExecSuccOut Number of distance-based inter-

frequency handover executionattempts

1526730011 L.HHO.InterFddTdd.Distance.PrepAttOut Number of distance-based inter-duplex-mode handover preparationattempts

1526730013 L.HHO.InterFddTdd.Distance.ExecAttOut Number of distance-based inter-duplex-mode handover executionattempts

1526730015 L.HHO.InterFddTdd.Distance.ExecSuccOut Number of successful distance-basedinter-duplex-mode handoverexecutions



Distance-Based Handover Threshold

Distance-based handover threshold is contained in the DistBasedHO MO.


























ParameterName


Distance-basedHandoverThreshold

DistBasedHO.DistBasedHOThd Network plan(negotiation notrequired)

This parameter specifies thethreshold for distance-basedhandovers.

It is recommended that you setthis parameter based on theplanned distance between sites.



ParameterName


Setting Notes

Local cell ID InterFreqHoGroup.LocalCel l Id Networkplan


Ensure that thisparameter has been

set in a Cell MObased on the networkplan.

CoverageBasedInterfreq RSRPthreshold

InterFreqHoGroup.InterFreqHoA4ThdRsrp Networkplan(negotiationnotrequired)

This parameterspecifies the RSRPthreshold for event A4in a coverage-based,UL-quality-based, ordistance-basedhandover, or in aSPID-based handoverto the HPLMN. Alarger value causes a

lower probability oftriggering event A4. Asmaller value causesa higher probability.

The value of thisparameter must begreater than the sumof the peer-end RSRPthreshold for event A2for inter-frequencymeasurement (set inthe

InterFreqHoGroup MO at the peereNodeB) and theRSRP threshold offsetfor event A2 for inter-frequencymeasurement (set intheCnOperatorHoCfg



ParameterName


Setting Notes

MO at the peereNodeB).

CoverageBased

Interfrq RSRQthreshold

InterFreqHoGroup.InterFreqHoA4ThdRsrq Network


This parameter

specifies the RSRQthreshold for event A4in a coverage-based,UL-quality-based, ordistance-basedhandover, or in aSPID-based handoverto the HPLMN. Alarger value causes alower probability oftriggering event A4. Asmaller value causesa higher probability.

The value of thisparameter must begreater than or equalto the peer-end RSRQthreshold for event A2for inter-frequencymeasurement set atthe peer eNodeB (setin theInterFreqHoGroup MO at the peereNodeB).

InterfreqHandOver Timeto Trigger

InterFreqHoGroup.InterFreqHoA4TimeToTrig Networkplan(negotiationnotrequired)

This parameterspecifies the time-to-trigger for event A4. Alarger value causes alower probability ofhandover to inter-frequency neighboringE-UTRAN cells and asmaller averagenumber of handovers,but a higher risk ofservice drops. Asmaller value causes

the opposite effect.

If both distance-basedinter-frequencyhandovers anddistance-based inter-RAT handovers areenabled, you areadvised to set the



ParameterName


Setting Notes

time-to-trigger for theinter-frequencyhandover event to be

smaller than that forthe inter-RAThandover event. Thishelps increase thepossibility of inter-frequency handovers.



ParameterName


Setting Notes

FreqPriorloadBased A4Measurementtriggerquantity

IntraRatHoComm.InterFreqHoA4TrigQuan

Networkplan(negotiationnotrequired)

This parameter specifiesthe event A4 triggeringquantity for inter-frequencyhandovers other thancoverage-based inter-frequency handovers. Thequantity can be eitherRSRP or RSRQ, or both.The measured RSRPvalues are stable, slightlyvarying with the load, andtherefore there is littlesignal fluctuation. Themeasured RSRQ values

vary with the load and arelikely to reflect the signalquality of the cell in realtime.



Fault Description

An event A4 measurement report may not be submitted when a UE moving toward the edge of acell that has overshoot coverage experiences a call drop.

Fault handling










2. Check the messages over the Uu interface for A4 measurement reports in RRC_MEAS_RPRT

messages prior to RRC_CONN_REL messages. If such reports cannot be found, this problem is due to inappropriate settings of handover

parameters. Go to 3.





7.5 UL-quality-based Inter-Frequency Handover

7.5.1 When to Use UL-quality-based Inter-Frequency Handover

Coverage-based inter-frequency handovers are triggered based on DL signal quality. However,there may be a huge imbalance between the DL and UL signal quality: The UL signal quality

may be relatively poor while the DL signal quality is fairly satisfactory. If this occurs, inter-

frequency handovers cannot be promptly triggered. To handle this problem, you can enable UL-

quality-based inter-frequency handover.


Before deploying UL-quality-based inter-frequency handover, collect the causes of theimbalance between the UL and DL signal quality as well as the possible magnitudes of the

imbalance. In addition, you need to collect the requirements of the local network plan for the UL

data rate at the cell edge.

7.5.3 Requirements


None


None

License

None
































Required Data



UL-quality-based inter-frequency handover can be enabled only after coverage-based inter-frequencyhandover is enabled. This section describes the required parameters except those for coverage-basedinter-frequency handover. For details on the required parameters for coverage-based inter-frequencyhandover, see the "Scenario-specific Data" part in 7.2.4 Data Preparation.

The following table describes the parameter that must be set in the ENodeBAlgoSwitch MO to configureUL-quality-based inter-frequency handover.

Paramet

er Name

Parameter ID Data

Source

Setting Notes

Handover Algoswitch

ENodeBAlgoSwitch.HoAlgo

Swi tch Networkplan(negotiation notrequired)

To enable UL-quality-based inter-frequencyhandover, select theUlQualityInterFreqHoSwitch(UlQualityInterFreqHoSwitch) check box under this parameter.

7.5.5 Activation


Enter the values of related parameters in a summary data file, which also contains other data for the neweNodeBs to be deployed. Then, import the summary data file into the Configuration Management Express

(CME) for batch configuration. For detailed instructions, see section "Creating eNodeBs in Batches" in theinitial configuration guide for the eNodeB.





Table 7-12 UL-Quality-based Inter-Frequency Handover



ENodeBAlgoSwitch User-defined sheet Handover Algo switch A list-typesheet isrecommended.























Mobile country code, Mobile

network code, eNodeB identity,Cell identity, DownlinkEARFCN, Uplink EARFCNindicator, Uplink EARFCN,Physical cell identity, Trackingarea code, Cell name

A list-type








Local cell identity, Downlink

EARFCN, Uplink EARFCNconfigure indicator, UplinkEARFCN, Inter frequency cellresel priority configure indicator,Inter frequency cell reselpriority, EUTRAN reselectiontime(s), Speed dependent reselparameter configuring indicator,Scaling factor of treseleutra inmedium mobility state, Scalingfactor of treseleutra in highmobility state, Measurementbandwidth(MHz), Frequency

offset(dB), Inter frequency highpriority threshold(2dB), Interfrequency lower prioritythreshold(2dB), Minimumrequired RX level(2dBm),PMAX configure indicator,PMAX(dBm), Neighbor cellconfig, Presence antenna port1,Inter-Freq HO trigger EventType

A list-type




Local cell identity, Mobilecountry code, Mobile networkcode, eNodeB identity, Cellidentity, Cell individualoffset(dB), Cell offset(dB), Nohandover indicator, No removeindicator, Blind handoverPriority, ANR flag, Local cellname, Neighbour cell name






1. Choose CME > Advanced > Customize Summary Data File (U2000 client mode), or chooseAdvanced > Customize Summary Data File (CME client mode), to customize a summary

data file for batch reconfiguration.

NOTE:




Data (U2000 client mode), or choose LTE Application > Import Data > Import Base StationBulk Configuration Data (CME client mode), to import the summary data file into the CME.5. Choose CME > Planned Area > Export Incremental Scripts (U2000 client mode), or choose




















Using MML Commands

1. Run the MOD ENODEBALGOSWITCH command to enable UL-quality-based inter-frequencyhandover.



b. (Optional) ADD EUTRANEXTERNALCELL, which is required when the inter-frequencyneighboring cell is under a different eNodeB from the local cell.

c. (Optional) ADD EUTRANEXTERNALCELLPLMN, which is used to configure the PLMNlist for an external E-UTRAN cell when the neighboring E-UTRAN cell works in RANsharing mode.





//Activating UL-quality-based inter-frequency handover

MOD ENODEBALGOSWITCH: HoAlgoSwitch=UlQualityInterFreqHoSwitch-1;


ADD EUTRANINTERNFREQ: LocalCellId=0, DlEarfcn=2860,UlEarfcnCfgInd=NOT_CFG, CellReselPriorityCfgInd=NOT_CFG,

SpeedDependSPCfgInd=NOT_CFG, MeasBandWidth=MBW100, PmaxCfgInd=NOT_CFG,QqualMinCfgInd=NOT_CFG;






1. Use a UE to access the network at the cell center in the 2600 MHz band. Then, move the UEfrom the cell center to the cell edge. During this process, the uplink quality of the UE becomespoor.

2. Observe the user-level measurement result on the U2000 (choose Monitor > Signaling Trace> Signaling Trace Management, and observe the value of BLER Monitoring in UserPerformance Monitoring.)

When the user uplink IBLER increases gradually, observe the messages traced over theUu interface. If the RRC_CONN_RECFG message from the eNodeB containsmeasurement control information for the inter-frequency handover and theRRC_CONN_RECFG message received by the eNodeB contains information of thetarget cell for an inter-frequency handover, you can infer that UL-quality-based inter-frequency handover has been activated.

When the user uplink IBLER increases suddenly but has not reached 99%, observe the

messages traced over the Uu interface. If the RRC_CONN_REL message from theeNodeB contains target frequency information, you can infer that UL-quality-based inter-frequency handover has been activated.

3. Observe the messages traced over the Uu interface again.

As the uplink IBLER of the UE increases, if the RRC_CONN_RECFG message, which is ahandover command, contains the target cell access information, you can infer that UL-quality-based inter-frequency handover has been triggered.

7.5.7 Deactivation


Batch reconfiguration using the CME is the recommended method to deactivate a feature on eNodeBs.

This method reconfigures all data, except neighbor relationships, for multiple eNodeBs in a singleprocedure. The procedure for feature deactivation is similar to that for feature activation described inUsing the CME to Perform Batch Configuration for Existing eNodeBs. In the procedure, modify relatedparameters described below.

Table 7-13 Parameters related to UL-quality-based inter-frequency handover














ENodeBAlgoSwitch ENodeBAlgoSwitch Handover Algo switch Clear theUlQualityInterFreqHoSwitch check box.



Using MML Commands

To deactivate UL-quality-based inter-frequency handover, disable its algorithm by running the MODENODEBALGOSWITCH command.


//Deactivating UL-quality-based inter-frequency handover

MOD ENODEBALGOSWITCH: HoAlgoSwitch=UlQualityInterFreqHoSwitch-0;


The handover success rate and service drop rate used for monitoring the performance of UL-quality-based inter-frequency handover are the same as those for monitoring the performance of coverage-based inter-frequency handover. For details, see 7.2.8 Performance Monitoring.

Table 7-14 lists the counters related to UL-quality-based inter-frequency and inter-mode handover.

Table 7-14 Counters related to UL-quality-based inter-frequency and inter-mode handover


1526729994 L.HHO.InterFreq.ULquality.PrepAttOut Number of UL-quality-based inter-frequency handover preparationattempts

1526729996 L.HHO.InterFreq.ULquality.ExecAttOut Number of UL-quality-based inter-frequency handover executionattempts

1526729998 L.HHO.InterFreq.ULquality.ExecSuccOut Number of successful UL-quality-based inter-frequency handoverexecutions

1526729995 L.HHO.InterFddTdd.ULquality.PrepAttOut Number of UL-quality-based inter-duplex-mode handover preparation

attempts

1526729997 L.HHO.InterFddTdd.ULquality.ExecAttOut Number of UL-quality-based inter-duplex-mode handover executionattempts

1526729999 L.HHO.InterFddTdd.ULquality.ExecSuccOut Number of successful UL-quality-based inter-duplex-mode handoverexecutions





















ParameterName


Setting Notes

Local cell ID InterFreqHoGroup.LocalCel l Id Networkplan(negotiationnotrequired)

Ensure that thisparameter has beenset in a Cell MObased on the networkplan.

CoverageBasedInterfreq RSRP

threshold

InterFreqHoGroup.InterFreqHoA4ThdRsrp Networkplan


This parameterspecifies the RSRP

threshold for event A4in a coverage-based,UL-quality-based, ordistance-basedhandover, or in aSPID-based handoverto the HPLMN. Alarger value causes alower probability oftriggering event A4. Asmaller value causesa higher probability.

The value of thisparameter must begreater than the sumof the peer-end RSRPthreshold for event A2for inter-frequencymeasurement (set intheInterFreqHoGroup MO at the peereNodeB) and theRSRP threshold offsetfor event A2 for inter-frequencymeasurement (set intheCnOperatorHoCfg MO at the peereNodeB).

CoverageBasedInterfrq RSRQthreshold

InterFreqHoGroup.InterFreqHoA4ThdRsrq Networkplan(negotiation

This parameterspecifies the RSRQthreshold for event A4












ParameterName


Setting Notes

notrequired)

in a coverage-based,UL-quality-based, ordistance-based

handover, or in aSPID-based handoverto the HPLMN. Alarger value causes alower probability oftriggering event A4. Asmaller value causesa higher probability.

The value of thisparameter must begreater than or equalto the peer-end RSRQthreshold for event A2for inter-frequencymeasurement set atthe peer eNodeB (setin theInterFreqHoGroup MO at the peereNodeB).

InterfreqHandOver Timeto Trigger

InterFreqHoGroup.InterFreqHoA4TimeToTrig Networkplan(negotiationnotrequired)

This parameterspecifies the time-to-trigger for event A4. Alarger value causes alower probability of

handover to inter-frequency neighboringE-UTRAN cells and asmaller averagenumber of handovers,but a higher risk ofservice drops. Asmaller value causesthe opposite effect.

If both UL-quality-based inter-frequencyhandovers and UL-

quality-based inter-RAT handovers areenabled, you areadvised to set thetime-to-trigger for theinter-frequencyhandover event to besmaller than that forthe inter-RAT



ParameterName


Setting Notes

handover event,increasing thepossibility of inter-

frequency handovers.Intra-RAT Inter-Frequency Handover Parameters


ParameterName


Setting Notes

FreqPriorloadBased A4Measurementtrigger

quantity

IntraRatHoComm.InterFreqHoA4TrigQuan Networkplan(negotiationnotrequired)

This parameter specifiesthe event A4 triggeringquantity for inter-frequencyhandovers other thancoverage-based inter-

frequency handovers. Thequantity can be eitherRSRP or RSRQ, or both.The measured RSRPvalues are stable, slightlyvarying with the load, andtherefore there is littlesignal fluctuation. Themeasured RSRQ valuesvary with the load and arelikely to reflect the signalquality of the cell in realtime.



Fault description

An event A4 measurement report may not be submitted when a UE moving toward the cell edgeexperiences a call drop.

Fault handling














2. Check the messages over the Uu interface for A4 measurement reports in RRC_MEAS_RPRTmessages prior to RRC_CONN_REL messages.



Interfreq handover hysteresis CoverageBased Interfreq RSRP threshold



7.6.1 When to Use Frequency-Priority-based Inter-Frequency Handover

Frequency-priority-based inter-frequency handover applies to the following scenario:

Some eNodeB sites use a high frequency band (for example, 2600 MHz) and a low band (for example,900 MHz) as co-coverage bands. The high band is preferentially used to provide services, and the low

band is used to ensure continuous coverage.

In this scenario, frequency-priority-based inter-frequency handover can be used to hand over

UEs from the low to high band.

Note that frequency-priority-based inter-frequency handovers are performed to transfer UEs only

from the low band to the high band. If a UE needs to be handed over from the high band to thelow band, a coverage-based inter-frequency handover can be performed.


To prevent failures in frequency-priority-based inter-frequency handovers, verify that blind handover is

disabled and the high and low bands have the same coverage.Collect information about the coverage of the high and low bands. This information serves as a basis forsetting the thresholds used to trigger events A1, A2, and A4.

If blind handover is used in frequency-priority-based inter-frequency handover scenarios, collectinformation about the neighboring cells to configure them with blind handover priorities in the range of 17to 32.

7.6.3 Requirements


None


None

License

None

























Network plan (negotiation required): parameter values planned by the operator and negotiated

with the EPC or peer transmission equipment Network plan (negotiation not required): parameter values planned and set by the operator


Required Data



Frequency-priority-based inter-frequency handover can be enabled only after coverage-based inter-frequency handover is enabled. This section describes the required parameters except those forcoverage-based inter-frequency handover. For details on the required parameters for coverage-based

inter-frequency handover, see the "Scenario-specific Data" part in 7.2.4 Data Preparation.

The following table describes the parameter that must be set in the CellAlgoSwitch MO to configurefrequency-priority-based inter-frequency handover.

ParameterName


Setting Notes

FreqPriorityHoSwitch

CellAlgoSwitch.FreqPriori ty HoSwi tch


To enable frequency-priority-based inter-frequency handover in scenarios where thehigh and low bands have the samecoverage under the same eNodeB and thelow band has a smaller bandwidth, selectthe

FreqPriorIFHOSwitch(FreqPriorIFHOSwitch) check box. You are advised not toselect this check box for other scenarios.

To enable frequency-priority-based blindhandover, select theFreqPriorIFBlindHOSwitch(FreqPriorIFBlindHOSwitch) check box.

The following table describes the parameter that must be set in the EutranInterFreqNCell MO toconfigure the blind handover priorities for inter-frequency neighboring cells.

Parameter

Name

Parameter ID Data

Source

Setting Notes

BlindhandoverPriority

EutranInterFreqNCell.Bl indHoPr ior i ty Networkplan(negotiationnotrequired)

If this parameter value is set to 0,blind handovers and frequency-priority-based handovers cannot beperformed. The values 1 to 16 indicate blind-handover priorities.Multiple neighboring cells can beconfigured with the same blind-















ParameterName


Setting Notes

handover priority. If multipleneighboring cells have the highestblind-handover priority, the eNodeB

randomly selects one from them.The values 17 to 32 indicate thepriorities for frequency-priority-based handovers. Set thisparameter to a value ranging from 1 to 16 only for those inter-frequencyneighboring cells that haveoverlapped coverage with theserving cell. Set this parameter to alarger value for a neighboring cellthat has wider overlapped coverageor a lower frequency. Set thisparameter to 0 for all inter-frequency neighboring cells if no

inter-frequency neighboring cellshave overlapped coverage with theserving cell.

7.6.5 Activation







Table 7-15 Frequency-Priority-based Inter-Frequency Handover



CellAlgoSwitch User-defined sheet

CellAlgoSwitch isrecommended.

Based on Frequency Priority HOSwitch










EutranExternalCell is

recommended.





Local cell identity, DownlinkEARFCN, Uplink EARFCNconfigure indicator, UplinkEARFCN, Inter frequency cellresel priority configure indicator,Inter frequency cell resel priority,EUTRAN reselection time(s),Speed dependent reselparameter configuring indicator,Scaling factor of treseleutra in

medium mobility state, Scalingfactor of treseleutra in highmobility state, Measurementbandwidth(MHz), Frequencyoffset(dB), Inter frequency highpriority threshold(2dB), Interfrequency lower prioritythreshold(2dB), Minimumrequired RX level(2dBm), PMAXconfigure indicator, PMAX(dBm),Neighbor cell config, Presenceantenna port1, Inter-Freq HOtrigger Event Type




Local cell identity, Mobile countrycode, Mobile network code,eNodeB identity, Cell identity,Cell individual offset(dB), Celloffset(dB), No handover indicator,No remove indicator, Blindhandover Priority, ANR flag,Local cell name, Neighbour cellname



EutranExternalCellPlmn

is recommended.

Mobile country code, Mobilenetwork code, eNodeB identity,Cell identity, Share mobile

country code, Share mobilenetwork code







NOTE:
























Using MML Commands

1. Run the MOD CELLALGOSWITCH command to enable frequency-priority-based inter-frequency handover.



b. ADD EUTRANINTERFREQNCELL

NOTE:

Set EutranInterFreqNCell.Bl indHOPrior i ty to a value ranging from 17 to 32.




To deactivate frequency-priority-based inter-frequency handover, disable its algorithm by running theMOD CELLALGOSWITCH command.


//Deactivating frequency-priority-based inter-frequency handover

MOD CELLALGOSWITCH: LocalCellId=0,FreqPriorityHoSwitch=FreqPriorIFHOSwitch-0;


The handover success rate and service drop rate used for monitoring the performance of frequency-priority-based inter-frequency handover are the same as those for monitoring the performance ofcoverage-based inter-frequency handover. For details, see 7.2.8 Performance Monitoring.

Table 7-17 lists the counters related to frequency-priority-based inter-frequency and inter-mode handover.

Table 7-17 Counters related to frequency-priority-based inter-frequency and inter-mode handover

Counter ID Counter Name Counter Description1526729482 L.HHO.InterFreq.FreqPri.PrepAttOut Number of frequency-priority-based

inter-frequency handover preparationattempts

1526729483 L.HHO.InterFreq.FreqPri.ExecAttOut Number of frequency-priority-basedinter-frequency handover executionattempts

1526729484 L.HHO.InterFreq.FreqPri.ExecSuccOut Number of successful frequency-priority-based inter-frequencyhandover executions

1526730006 L.HHO.InterFddTdd.FreqPri.PrepAttOut Number of frequency-priority-based

inter-duplex-mode handoverpreparation attempts

1526730007 L.HHO.InterFddTdd.FreqPri.ExecAttOut Number of frequency-priority-basedinter-duplex-mode handover executionattempts

1526730008 L.HHO.InterFddTdd.FreqPri.ExecSuccOut Number of successful frequency-priority-based inter-duplex-modehandover executions


The reconfiguration of parameters that are not involved in this section is the same as the reconfiguration

of parameters for coverage-based inter-frequency handovers. For details, see 7.2.9 ParameterOptimization.
























Parameter

Name


Setting Notes

Localcell ID

InterFreqHoGroup.LocalCel l Id Networkplan(negotiation notrequired)

Ensure that this parameter has beenset in a Cell MO based on the networkplan.


InterFreqHoGroup.InterFreqLoadBased HoA4ThdRsrp


This parameter specifies the RSRPthreshold for event A4 for load-based,frequency-priority-based, and service-based inter-frequency handovers. Alarger value causes a lower probabilityof triggering event A4. A smaller valuecauses a higher probability.

The value of this parameter must be

greater than the sum of the peer-endRSRP threshold for event A2 for inter-frequency measurement (set in theInterFreqHoGroup MO at the peereNodeB) and the RSRP thresholdoffset for event A2 for inter-frequencymeasurement (set in theCnOperatorHoCfg MO at the peereNodeB).

LoadBasedInterfrqRSRQthreshold

InterFreqHoGroup.InterFreqLoadBased HoA4ThdRsrq


This parameter specifies the RSRQthreshold for event A4 for load-based,frequency-priority-based, and service-based inter-frequency handovers. Alarger value causes a lower probabilityof triggering event A4. A smaller valuecauses a higher probability.

The value of this parameter must begreater than the sum of the peer-endRSRQ threshold for event A2 for inter-frequency measurement (set in theInterFreqHoGroup MO at the peereNodeB) and the RSRQ thresholdoffset for event A2 for inter-frequencymeasurement (set in theCnOperatorHoCfg MO at the peereNodeB).

FreqPriorityBasedInterfreq A1RSRP

InterFreqHoGroup.FreqPri InterFreqHo A1ThdRsrp


This parameter specifies the RSRPthreshold for event A1 for frequency-priority-based inter-frequencyhandovers. A larger value causes alower probability of triggering event A1.



Parameter

Name


Setting Notes

threshold

A smaller value causes a higherprobability.

Set this parameter based on the actualconditions. You are advised to set thisparameter to the sum of peer-endRSRP threshold for event A2 for inter-frequency measurement (set in theInterFreqHoGroup MO at the peereNodeB), the RSRP threshold offset forevent A2 for inter-frequencymeasurement (set in theCnOperatorHoCfg MO at the peereNodeB), RSRP difference betweenfrequency bands, and compensation (6dB is recommended).

FreqPriorityBasedInterfreq A1RSRQthreshold

InterFreqHoGroup.FreqPri InterFreqHo A1ThdRsrq


This parameter specifies the RSRQthreshold for event A1 for frequency-priority-based inter-frequencyhandovers. A larger value causes alower probability of triggering event A1. A smaller value causes a higherprobability.

Set this parameter based on the actualconditions. You are advised to set thisparameter to the sum of the peer-endRSRQ threshold for event A2 for inter-

frequency measurement (set in theInterFreqHoGroup MO at the peereNodeB), RSRQ difference betweenfrequency bands, and compensation (3dB is recommended).

FreqPriorityBasedInterfreq A2RSRPthreshold

InterFreqHoGroup.FreqPri InterFreqHo A2ThdRsrp


This parameter specifies the RSRPthreshold for event A2 for frequency-priority-based inter-frequencyhandovers. It is used in determiningwhen to exit the gap-assistedmeasurement triggered by frequency-priority-based inter-frequencyhandover.

The value of this parameter must be(usually 4 dB) less than or equal to thevalue ofInterFreqHoGroup.FreqPri InterFreqH oA1ThdRsrp .

FreqPriority

InterFreqHoGroup.FreqPri InterFreqHo A2ThdRsrq

Networkplan

This parameter specifies the RSRQthreshold for event A2 for frequency-



Parameter

Name


Setting Notes

BasedInterfre

q A2RSRQthreshold

(negotiation not

required)

priority-based inter-frequencyhandovers. It is used in determining

when to exit the gap-assistedmeasurement triggered by frequency-priority-based inter-frequencyhandover.

The value of this parameter must be(usually 2 dB) less than or equal to thevalue ofInterFreqHoGroup.FreqPri InterFreqH oA1ThdRsrq .

Intra-RAT Handover


ParameterName


Setting Notes

A1Measurementtriggerquantity ofFreq Priority

IntraRatHoComm.FreqPri InterFreqHoA1TrigQuan Networkplan(negotiationnotrequired)

This parameterspecifies thetriggering quantityfor events A1 and A2 for frequency-priority-based inter-frequencymeasurement. Thequantity can beeither RSRP orRSRQ. Themeasured RSRPvalues are stable,slightly varying withthe load, andtherefore there islittle signalfluctuation. Themeasured RSRQvalues vary with theload and are likelyto reflect the signalquality of the cell in

real time.

It is recommendedthat the defaultvalue be used if thetraffic load of LTEcells is not stable.



ParameterName


Setting Notes

FreqPriorloadBased A4Measurementtriggerquantity

IntraRatHoComm.InterFreqHoA4TrigQuan Networkplan(negotiationnotrequired)

This parameterspecifies the event A4 triggeringquantity for inter-frequencyhandovers otherthan coverage-based inter-frequencyhandovers. Thequantity can beeither RSRP orRSRQ, or both. Themeasured RSRPvalues are stable,slightly varying withthe load, and

therefore there islittle signalfluctuation. Themeasured RSRQvalues vary with theload and are likelyto reflect the signalquality of the cell inreal time.

It is recommendedthat the defaultvalue be used if the

traffic load of LTEcells is not stable.


Fault description

An eNodeB may not initiate a handover procedure upon receipt of an event A1 measurement

report.

Fault handling

Perform the following steps to determine whether the blind handover priorities for neighboringcells are accurate:

1. Run the LST EUTRANINTERFREQNCELL command to list the inter-frequency neighboringcells. Check the list for cells whose blind handover priorities range from 17 to 32.

If such cells cannot be found, go to 2.

If such cells can be found, contact Huawei technical support engineers.










2. Run the MOD EUTRANINTERFREQNCELL command to change the blind handover prioritiesof neighboring cells for frequency-priority-based blind handovers to a value in the range from17 to 32.

8 Reference Documents

1. 3GPP TS 36.331, "RRC Protocol Specification"2. 3GPP TS 36.300, "E-UTRAN Overall description"3. 3GPP TS 36.423, "X2 Application Protocol"4. 3GPP TS 36.413, "S1 Application Protocol"5. 3GPP TS 23.203, "Policy and charging control architecture"6. 3GPP TS 36.104, "Base Station (BS) radio transmission and reception"7. 3GPP TS 23.401, "General Packet Radio Service (GPRS) enhancements for Evolved

Universal Terrestrial Radio Access Network (E-UTRAN) access"8. Idle Mode Management 9. ANR Management 10. MLB 11. ICIC 12. SRVCC


