huawei eran feature documentation

6/20/13 eRAN Feature Documentation

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eRAN

CS FallbackFeature Parameter Description

Copyright © Huawei Technologies Co., Ltd. 2013. All rights reserved.

No part of this document may be reproduced or transmitted in any form or by any means without prior written consent of Huawei Technologies Co., Ltd.

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The purchased products, services and features are stipulated by the contract made between Huawei and the customer. All or part of the products, services andfeatures described in this document may not be within the purchase scope or the usage scope. Unless otherwise specified in the contract, all statements,information, and recommendations in this document are provided "AS IS" without warranties, guarantees or representations of any kind, either express or implied.

The information in this document is subject to change without notice. Every effort has been made in the preparation of this document to ensure accuracy of thecontents, but all statements, information, and recommendations in this document do not constitute a warranty of any kind, express or implied.



Contents1 Introduction

1.1 Scope

1.2 Intended Audience

1.3 Change History

2 Overview of CSFB

2.1 Introduction

2.2 Benefits

2.3 Network Architecture for CSFB to UTRAN/GERAN

2.4 Network Architecture for CSFB to CDMA2000 1xRTT

3 End-to-End Procedures for CSFB

3.1 CSFB to UTRAN

3.1.1 Combined EPS/IMSI Attach Procedure

3.1.2 CSFB Procedures for Mobile-originated Calls and Mobile-terminated Calls

3.1.3 CSFB Procedure for SMS

3.1.4 CSFB Procedure for Emergency Calls

3.1.5 CSFB Procedure for LCS

3.1.6 RAN Information Management Procedure

3.2 CSFB to GERAN







3.3 CSFB to CDMA2000 1xRTT

3.3.1 Preregistration Procedure

3.3.2 CSFB Procedure for Mobile-originated Calls

3.3.3 CSFB Procedure for Mobile-terminated Calls



4 CSFB at the eNodeB

4.1 Triggering Phase of CSFB

4.1.1 Choosing Between a Blind Handover and a Measurement-based Handover

4.1.2 Selecting Frequencies to Measure or a Target Cell (Without an LAI)

4.1.3 Selecting Frequencies to Measure or a Target Cell (With an LAI)

4.2 Measurement Phase of CSFB

4.2.1 Measurement Configuration

4.2.2 Measurement Reporting

4.3 Decision Phase of CSFB

4.4 Execution Phase of CSFB

4.5 CSFB Exception Handling

5 Related Features

5.1 Features Related to LOFD-001033 CS Fallback to UTRAN

5.2 Features Related to LOFD-001034 CS Fallback to GERAN

5.3 Features Related to LOFD-001035 CS Fallback to CDMA2000 1xRTT

5.4 Features Related to LOFD-001052 Flash CS Fallback to UTRAN

5.5 Features Related to LOFD-001053 Flash CS Fallback to GERAN

5.6 Features Related to LOFD-001068 CS Fallback with LAI to UTRAN

5.7 Features Related to LOFD-001069 CS Fallback with LAI to GERAN

5.8 Features Related to LOFD-001078 E-UTRAN to UTRAN CS/PS Steering

6 Network Impact

6.1 LOFD-001033 CS Fallback to UTRAN

6.2 LOFD-001034 CS Fallback to GERAN


6.4 LOFD-001052 Flash CS Fallback to UTRAN

6.5 LOFD-001053 Flash CS Fallback to GERAN

6.6 LOFD-001068 CS Fallback with LAI to UTRAN

6.7 LOFD-001069 CS Fallback with LAI to GERAN

6.8 LOFD-001078 E-UTRAN to UTRAN CS/PS Steering

7 Engineering Guidelines

7.1 Deploying CSFB to UTRAN

7.1.1 When to Use CSFB to UTRAN

7.1.2 Information to Be collected

7.1.3 Deployment Requirements

7.1.4 Data Preparation

7.1.5 Precautions

7.1.6 Initial Configuration

7.1.7 Activation Observation

7.1.8 Deactivation

7.2 Deploying CSFB to GERAN

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7.2.1 When to Use CSFB to GERAN




7.2.5 Precautions



7.2.8 Deactivation

7.3 Deploying CSFB to CDMA2000 1xRTT

7.3.1 When to Use CSFB to CDMA2000 1xRTT




7.3.5 Precautions



7.3.8 Deactivation

7.4 Deploying Flash CSFB to UTRAN

7.4.1 When to Use Flash CSFB to UTRAN




7.4.5 Precautions



7.4.8 Deactivation

7.5 Deploying Flash CSFB to GERAN

7.5.1 When to Use Flash CSFB to GERAN




7.5.5 Precautions



7.5.8 Deactivation

7.6 Deploying CSFB with LAI to UTRAN

7.6.1 When to Use CSFB with LAI to UTRAN




7.6.5 Precautions



7.6.8 Deactivation

7.7 Deploying CSFB with LAI to GERAN

7.7.1 When to Use CSFB with LAI to GERAN




7.7.5 Precautions



7.7.8 Deactivation

7.8 Deploying E-UTRAN to UTRAN CS/PS Steering

7.8.1 When to Use E-UTRAN to UTRAN CS/PS Steering




7.8.5 Precautions



7.8.8 Deactivation

7.9 Performance Optimization

7.9.1 Monitoring

7.9.2 Parameter Optimization

7.9.3 EBC Description

7.10 Troubleshooting

7.10.1 Fault 1

7.10.2 Fault 2

7.10.3 Fault 3

7.10.4 CS Fallback with LAI to UTRAN

7.10.5 CS Fallback with LAI to GERAN

8 Parameters












































































9 Counters

10 Glossary

11 Reference Documents

1 Introduction

1.1 Scope

This document describes the principles and procedures of Circuit Switched Fallback (CSFB), and it illustrates the functions provided by Huawei E-UTRAN NodeBs(eNodeBs) during CSFB procedures. It also provides engineering guidelines for setting the essential parameters related to CSFB.

Any managed objects (MOs), parameters, alarms, or counters described in this document correspond to the software release delivered with this document. In theevent of updates, the updates will be described in the product documentation delivered with the latest software release.

1.2 Intended Audience

This document is intended for:

Personnel who need to understand CSFB

Personnel who work with Huawei Long Term Evolution (LTE) products

1.3 Change History

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

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

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

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

Document Issues

The document issues are as follows:

06 (2013-05-20)

05 (2012-12-29)

04 (2012-09-20)

03 (2012-06-30)

02 (2012-05-11)

01 (2012-03-30)

Draft A (2012-01-10)

06 (2013-05-20)

Compared with issue 05 (2012-12-29) of eRAN3.0, issue 06 (2013-05-20) of eRAN3.0 includes the following changes.

Change Type Change Description Parameter Change

Feature change None None

Editorial change Added engineering guidelines for E-UTRAN to UTRANCS/PS Steering. For details, see section 7.8 "Deploying E-UTRAN to UTRAN CS/PS Steering."

None

05 (2012-12-29)



Feature change Modified the handling methods for CSFB exceptions. Fordetails, see section 4.5 "CSFB Exception Handling."

None

Editorial change Added flowcharts of CSFB execution. For details, see

section 4.4 "Execution Phase of CSFB."

Deleted the license control item IDs.

None

04 (2012-09-20)



Feature change None None

Editorial change Modified some descriptions of initial configuration inchapter 7 "Engineering Guidelines."

None

03 (2012-06-30)



Feature change Modified the mechanism for an eNodeB to selectfrequencies to measure or a target cell. For details, seesection 4.1.2 "Selecting Frequencies to Measure or aTarget Cell (Without an LAI)."

Added theUtranNFreq.CsPriorityparameter.

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Editorial change Modified some descriptions in sections 4.1.1 "ChoosingBetween a Blind Handover and a Measurement-basedHandover" and 4.4 "Execution Phase of CSFB."

None

02 (2012-05-11)



Feature change Added the UTRAN frequency layermeasurement function. For details, seesection 4.1.2 "Selecting Frequencies toMeasure or a Target Cell (Without an LAI)."

Added theENodeBAlgoSwitch.FreqLayerSwtichparameter.

Editorial changeModified some descriptions. None

01 (2012-03-30)

This is the first official release.

Compared with draft A (2012-01-10) of eRAN3.0, issue 01 (2012-03-30) of eRAN3.0 includes the following changes.


Feature change Modified the RAN information management (RIM)procedure during which the eNodeB obtains the systeminformation of the neighboring GERAN or UTRAN cells.For details, see sections 3.1.6 "RAN InformationManagement Procedure" and 3.2.6 "RAN InformationManagement Procedure."

None

Editorial change Revised chapter 7 "Engineering Guidelines." None

Draft A (2012-01-10)

This is a draft.

Compared with issue 02 (2011-09-30) of eRAN2.2, draft A (2012-01-10) of eRAN3.0 includes the following changes.


Feature change Added the description of how the eNodeB performs CSFBbased on an LAI. For details, see sections 4.1.3 "SelectingFrequencies to Measure or a Target Cell (With an LAI)"and 4.3 "Decision Phase of CSFB."

None

Editorial change Optimized the organization and description of this

document.

Added chapters 5 "Related Features" and 6 "Impact on

the Networks."

None

2 Overview of CSFB

This chapter illustrates the network architectures for CSFB to UTRAN/GERAN/CDMA2000 1xRTT and describes the function of each network element (NE).

In the early phase of EPS construction, operators who own a mature UTRAN, GERAN, or CDMA2000 1xRTT network can protect their investments in legacy CSnetworks and reduce their investments in the EPS by using legacy CS networks to provide CS services and using the EPS to provide PS services. From atechnological perspective, CSFB and VoIP over IMS are the two standard solutions to provide CS services for E-UTRAN UEs. After the technological maturity,industry chain, and deployment costs of the two methods are well weighed, CSFB is chosen to serve as an interim solution for CS service access before maturecommercial use of IMS.

EPS: evolved packet system

UTRAN: universal terrestrial radio access network

GERAN: GSM/EDGE radio access network

CDMA2000 1xRTT: CDMA2000 1x Radio Transmission Technology

CS: circuit switched

PS: packet switched

VoIP: voice over IP

IMS: IP multimedia subsystem

UE: user equipment

CSFB enables E-UTRAN UEs to fall back to CS networks to receive CS services, better utilizing legacy CS networks. Examples of CS services include voiceservices and location services (LCS). CSFB is a session setup procedure. UEs fall back to CS networks before CS sessions are set up, and they always stay in theCS networks during the CS sessions.

CSFB applies to scenarios in which the coverage area of the UTRAN/GERAN/CDMA2000 1xRTT network is the same as or includes that of the E-UTRAN. Itrequires a simpler network architecture compared with VoIP over IMS.

To implement CSFB, all mobile switching centers (MSCs) that serve overlapping areas with the E-UTRAN coverage must be upgraded to support functionsinvolving the SGs interface. The SGs interface is between an MSC and a mobility management entity (MME). Functions involving the SGs interface includecombined attach, combined TAU/LAU (TAU is short for tracking area update, and LAU is short for location area update), paging, and short message service (SMS).If an MSC pool is used in the legacy CS network, the upgrade of one or several MSCs in the pool is sufficient.

The optional features addressed in this document are as follows:

LOFD-001033 CS Fallback to UTRAN

LOFD-001034 CS Fallback to GERAN

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LOFD-001035 CS Fallback to CDMA2000 1xRTT

LOFD-001052 Flash CS Fallback to UTRAN

LOFD-001053 Flash CS Fallback to GERAN

LOFD-001068 CS Fallback with LAI to UTRAN

LOFD-001069 CS Fallback with LAI to GERAN

Table 2-1 lists the optional features addressed in this document and the corresponding chapters describing related principles and algorithms.

Table 2-1 Optional features related to CSFB and corresponding chapters

Feature Its Basic Principles AreDescribed in...

Its Algorithm Details Are Described in...

LOFD-001033 CS Fallbackto UTRAN

3.1 "CSFB to UTRAN" 4 "CSFB at the eNodeB"

LOFD-001034 CS Fallbackto GERAN

3.2 "CSFB to GERAN" 4 "CSFB at the eNodeB"

LOFD-001035 CS Fallbackto CDMA2000 1xRTT

3.3 "CSFB to CDMA20001xRTT"

4 "CSFB at the eNodeB"

LOFD-001052 Flash CSFallback to UTRAN

3.1.6 "RAN InformationManagement Procedure"


LOFD-001053 Flash CSFallback to GERAN

3.2.6 "RAN InformationManagement Procedure"


LOFD-001068 CS Fallbackwith LAI to UTRAN

3.1 "CSFB to UTRAN" 4.1.3 "Selecting Frequencies to Measure ora Target Cell (With an LAI)"

LOFD-001069 CS Fallbackwith LAI to GERAN

3.2 "CSFB to GERAN" 4.1.3 "Selecting Frequencies to Measure ora Target Cell (With an LAI)"

2.1 Introduction

As specified in 3GPP TS 23.272 V8.5.0, CSFB is a solution that enables a UE to register with both an EPS network and a legacy CS network. When such a UEinitiates a voice service, the EPS network instructs the UE to fall back to the legacy CS network before performing the service.

When a UE sends or receives an SMS message, the message is transmitted between the EPS network and the legacy CS network without requiring CSFB. This isachieved by SMS over SGs.

2.2 Benefits

CSFB brings the following benefits:

Facilitates voice services for the LTE network.

Facilitates SMS and LCS services for the LTE network.

Helps operators reduce costs by reusing legacy CS networks and not requiring IMS network deployment.

2.3 Network Architecture for CSFB to UTRAN/GERAN

To implement CSFB to UTRAN/GERAN, an SGs interface is required between the MME and the MSC server. Figure 2-2 shows the network architecture for CSFB toUTRAN/GERAN.

Figure 2-2 Network architecture for CSFB to UTRAN/GERAN

SGSN: serving GPRS support node

After a UE is powered on in the E-UTRAN as shown in Table 2-2, it initiates a combined EPS/IMSI attach procedure. Then, the MME performs a UE location updateover the SGs interface so that the core network of the UTRAN or GERAN learns about the UE location.

If a UE is camping on an E-UTRAN cell, it periodically initiates a combined TAU/LAU procedure, which allows for simultaneous UE location updates both in the MMEand in the core network of the UTRAN or GERAN.

The combined EPS/IMSI attach and combined TAU/LAU procedures are performed by exchanging non-access stratum (NAS) messages. Therefore, they aretransparent to the E-UTRAN (the E-UTRAN is unaware of them). When a mobile-originated or mobile-terminated CS service is initiated, the E-UTRAN works withother elements in the networks to perform CSFB.

Table 2-2 describes the elements of the network architecture for CSFB to UTRAN/GERAN.

Table 2-2 Elements of the network architecture for CSFB to UTRAN/GERAN

Element Function

SGs interface Acts as an interface between the MME and the MSC server.

Assists mobility management and paging between the EPS and the CS network.

Transmits SMS messages.

Transmits messages related to combined attach and combined TAU/LAU.

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UE Is capable of accessing the EPS and accessing the UTRAN, GERAN, or both.

Supports combined EPS/IMSI attach, combined EPS/IMSI detach, and combined

TAU/LAU.

Supports CSFB mechanisms, such as PS redirection and PS handover.

IMSI is short for international mobile subscriber identity.

CSFB-capable UEs must support SMS over SGs, but UEs that support SMS over SGs are

not necessarily CSFB-capable.

MME Supports the SGs interface to the MSC.

Selects the location area identity (LAI) based on the tracking area identity (TAI)

of the serving cell.

Supports the ability to forward paging messages delivered by the MSC.

Performs public land mobile network (PLMN) selection and reselection.

Supports combined EPS/IMSI attach, combined EPS/IMSI detach, and combined

TAU/LAU.

Routes CS signaling.

Supports SMS over SGs.

Supports RIM if flash CSFB or CCO with NACC is used as the CSFB mechanism.

CCO: cell change order

NACC: network assisted cell change

RIM: RAN information management

MSC Supports combined EPS/IMSI attach.

Supports SMS over SGs.

Forwards paging messages transmitted through the SGs interface.

E-UTRAN Forwards paging messages related to CSFB.

Selects target cells for CSFB for E-UTRAN UEs.

Supports one or more of the following functions:

− PS redirection to UTRAN or GERAN, if PS redirection is used as the CSFBmechanism

− PS handover to UTRAN or GERAN, if PS handover is used as the CSFBmechanism

− CCO without NACC to GERAN, if CCO without NACC is used as the CSFBmechanism; RIM for acquiring the system information of GERAN cells, if NACCis used as the CSFB mechanism

− RIM for acquiring the system information of UTRAN or GERAN cells, in additionto PS redirection, if flash CSFB is used as the CSFB mechanism

UTRAN/GERAN Supports one or more of the following functions:

Incoming handovers from the E-UTRAN, if PS handover is used as the CSFB

mechanism

RIM for delivering the system information of GERAN cells to eNodeBs, if NACC is

used as the CSFB mechanism

RIM for delivering the system information of UTRAN or GERAN cells to eNodeBs,

in addition to PS redirection, if flash CSFB is used as the CSFB mechanism

The UTRAN and GERAN do not need to provide extra functions to support PS redirection. TheGERAN does not need to provide extra functions to support CCO without NACC.

SGSN Does not activate Idle Mode Signaling Reduction (ISR) during the combined

RAU/LAU procedure initiated by the UE. RAU is short for routing area update.

Supports RIM if flash CSFB or CCO with NACC is used as the CSFB mechanism.

ISR is a mechanism for reducing the inter-RAT cell reselection signaling of a UE in idlemode. RAT is short for radio access technology. For details about ISR, see Annex J in 3GPPTS 23.401 V9.2.0.

2.4 Network Architecture for CSFB to CDMA2000 1xRTT

Figure 2-2 shows the network architecture for CSFB to CDMA2000 1xRTT. This CSFB function is implemented based on the S102 interface between the MME andthe 1xCS IWS. The S102 interface provides a tunnel between the MME and the 1xCS IWS to relay 3GPP2 1xCS signaling. 1xCS IWS is short for Circuit SwitchedFallback Interworking Solution Function for 3GPP2 1xCS.

Figure 2-3 Network architecture for CSFB to CDMA2000 1xRTT

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S-GW: serving gateway P-GW: PDN gateway

After a UE is powered on and attached to the evolved packet core (EPC), as shown in Figure 2-2, the MME is informed of the UE's CSFB capability. Then, theserving E-UTRAN cell broadcasts system information to indicate whether the E-UTRAN supports CSFB to CDMA2000 1xRTT. If the E-UTRAN supports CSFB toCDMA2000 1xRTT, the UE initiates preregistration with the CDMA2000 1xCS domain through the E-UTRAN and MME. After the preregistration, the CDMA20001xCS domain is informed of the UE location. When a mobile-originated or mobile-terminated CS service is initiated, the E-UTRAN works with other elements in thenetworks to perform CSFB.

Table 2-3 describes the elements of the network architecture for CSFB to CDMA2000 1xRTT.

Table 2-3 Elements of the network architecture for CSFB to CDMA2000 1xRTT

Element Function

S102 interface Acts as an interface between the MME and the 1xCS IWS.

Provides a tunnel to carry 1xCS signaling.

UE Is capable of accessing the EPS and CDMA2000 1xCS domain.

Preregisters with the CDMA2000 1xCS domain while camping on an E-UTRAN

cell and reregisters with the CDMA2000 1xCS domain while moving.

Supports CSFB mechanisms.

Supports mobile-originated and mobile-terminated SMS over S102.

MME Sends and receives 1xCS signaling over the S102 interface, buffers data, and

performs tunnel reestablishment.

Redirects inter-MME S102 tunnels in the case of MME relocation.

E-UTRAN Broadcasts system information that contains CDMA2000 1xCS domain

information to trigger UEs' preregistration with the CDMA2000 1xCS domain.

Transmits 1xCS signaling.

Transmits paging messages from the 1xCS domain.

3 End-to-End Procedures for CSFB

This chapter describes the functions that a Huawei eNodeB performs during end-to-end procedures for CSFB, including the following:

Combined EPS/IMSI attach

Preregistration

CSFB procedure for mobile-originated calls

CSFB procedure for mobile-terminated calls

CSFB procedure for SMS

CSFB procedure for emergency calls

CSFB procedure for LCS

Regarding the capabilities of UEs and networks, Huawei provides the following mechanisms for eNodeBs to perform CSFB to UTRAN, GERAN, or CDMA20001xRTT for mobile-originated calls and mobile-terminated calls:

PS redirection

PS handover

CCO with or without NACC (CCO/NACC)

3.1 CSFB to UTRAN

For details about engineering guidelines for CSFB to UTRAN, see section 7.1 "Deploying CSFB to UTRAN."


The combined EPS/IMSI attach procedure is performed by exchanging NAS messages. Therefore, this procedure is transparent to the eNodeBs. After a CSFB-capable UE is powered on in the E-UTRAN, the UE initiates a combined EPS/IMSI attach procedure, as shown in Figure 3-1.

Figure 3-1 Combined EPS/IMSI attach procedure

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HSS: home subscriber server VLR: visitor location register

The symbols that appear in signaling procedure figures are explained as follows:

An arrow denotes the transmission of a message.

A plain box denotes a mandatory procedure.

A box of dashes denotes an optional procedure.

The combined EPS/IMSI attach procedure is described as follows:

1. The UE sends an Attach Request message to the MME, requesting a combined EPS/IMSI attach procedure. This message also indicates whether the CSFB orSMS over SGs function is required.

2. The EPS attach procedure is performed in the same way as it is performed within the LTE system. For details, see section 5.3.2 in 3GPP TS 23.401 V9.2.0.

3. The MME allocates an LAI to the UE, and then it finds the MSC/VLR for the UE based on the LAI. If multiple PLMNs are available for the CS domain, the MMEselects a CS PLMN based on the selected PLMN information reported by the eNodeB. Then, the MME sends the MSC/VLR a Location Update Requestmessage, which contains the new LAI, IMSI, MME name, and location update type.

4. The MSC/VLR performs the location update procedure in the CS domain.

5. The MSC/VLR responds with a Location Update Accept message that contains information about the VLR and temporary mobile subscriber identity (TMSI). Thelocation update procedure is successful.

6. The UE is informed that the combined EPS/IMSI attach procedure is successful. If the network supports SMS over SGs but not CSFB, the message transmittedto the UE contains the information element (IE) SMS-only. The message indicates that the combined EPS/IMSI attach procedure is successful but only SMSservices are supported.


Based on the capabilities of UEs and networks, the following mechanisms are available for an eNodeB to perform CSFB to UTRAN:

CSFB based on PS handover

CSFB based on PS redirection

Flash CSFB

Table 3-1 lists the advantages and disadvantages of the preceding mechanisms in terms of impacts on the UEs, impacts on the networks, CS service access delay,and PS service interruption time. The preceding mechanisms can be based on the measurement or blind mode, and they are compared here based on the samemode.

Table 3-1 Comparison of fallback mechanisms for CSFB to UTRAN

Fallback Mechanism Impact on theNetworks

Impact onthe UEs

CS Service AccessDelay

PS ServiceInterruption Time

CSFB based on PShandover

Complex Complex Short Short

CSFB based on PSredirection

Simple Simple Long Long

Flash CSFB Medium Medium Short Medium

CSFB Based on PS Handover

During CSFB based on PS handover, the UE is transferred from the E-UTRAN to the UTRAN by performing a PS handover. It then initiates a CS service in theUTRAN.

CSFB Procedure for Mobile-originated Calls

This section describes the procedure for CSFB to UTRAN based on PS handover for mobile-originated calls, as shown in Figure 3-2.

Figure 3-2 CSFB to UTRAN based on PS handover for mobile-originated calls

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RNC: radio network controller

The procedure is described as follows:

1. The UE sends the MME an NAS message Extended Service Request to initiate a CS service.

2. The MME sends an S1-AP Request message to instruct the eNodeB to initiate a CSFB procedure. If the MME supports the LAI-related feature, the MME alsodelivers the LAI to the eNodeB.

3. The eNodeB determines whether to perform a blind handover based on the UE capabilities, parameters settings, and algorithm policies. For details, see section4.1.1 "Choosing Between a Blind Handover and a Measurement-based Handover."

4. The eNodeB initiates the preparation phase for a PS handover. If the preparation is successful, the eNodeB instructs the UE to perform a handover.

The eNodeB selects a fallback mechanism and a target cell using the CSFB algorithm. For details, see chapter 4 "CSFB at the eNodeB."

5. After the handover, the UE may initiate a CS call establishment procedure with an LAU or combined RAU/LAU procedure in the UTRAN.

6. The follow-up procedures are performed for the PS handover. These procedures include data forwarding, path switching, and RAU. This step is performedtogether with step 5.

For details about the PS handover procedure, see Mobility Management in Connected Mode Feature Parameter Description and section 5.5.2 in 3GPP TS 23.401 V9.2.0.

CSFB Procedure for Mobile-terminated Calls

This section describes the procedure for CSFB to UTRAN based on PS handover for mobile-terminated calls, as shown in Figure 3-3.

Figure 3-3 CSFB to UTRAN based on PS handover for mobile-terminated calls


1. The MSC sends a Paging Request message from the CS domain to the MME over the SGs interface. Then, either of the following occurs:

− If the UE is in idle mode, the MME sends a Paging message to the eNodeB. Then the eNodeB sends a Paging message over the Uu interface to inform the UEof an incoming call from the CS domain.

− If the UE is in active mode, the MME sends the UE an NAS message to inform the UE of an incoming call from the CS domain.

2. The UE sends an Extended Service Request message containing a CS Fallback Indicator after receiving the paging message from the CS domain.

3. The MME instructs the eNodeB over the S1 interface to perform CSFB.

4. The subsequent steps are similar to steps 3 through 6 in the procedure for CSFB to UTRAN based on PS handover for mobile-originated calls. The onlydifference is that the UE sends a Paging Response message from the UTRAN cell.

CSFB Based on PS Redirection

During CSFB based on PS redirection, the eNodeB receives a CS Fallback Indicator, and then it sends an RRC Connection Release message to release the UE.The message contains information about a target UTRAN frequency, reducing the time for the UE to search for a target network. After selecting the UTRAN, the UEacquires the system information of a UTRAN cell. Then, the UE performs initial access to the cell to initiate a CS service. For the UTRAN, the UE is an initiallyaccessing user.


This section describes the procedure for CSFB to UTRAN based on PS redirection for mobile-originated calls, as shown in Figure 3-4.

Figure 3-4 CSFB to UTRAN based on PS redirection for mobile-originated calls






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4. The eNodeB sends an RRC Connection Release message to instruct the UE to perform a redirection. The message contains information about a target UTRANfrequency. Then, the eNodeB initiates an S1 UE context release procedure.


5. The UE may initiate an LAU, a combined RAU/LAU, or both an RAU and an LAU in the target cell.

6. The UE initiates a CS call establishment procedure in the target UTRAN cell.


In a mobile-terminated call, the MSC sends a Paging Request message from the CS domain to the MME over the SGs interface. Then, the MME or the eNodeBinitiates a paging procedure for the UE, as shown in Figure 3-3. The subsequent steps are the same as the steps in the procedure for CSFB to UTRAN based onPS redirection for mobile-originated calls.

Flash CSFB

During the flash CSFB procedure, the eNodeB receives a CS Fallback Indicator, and then it sends an RRC Connection Release message to release the UE. Themessage contains information about a target UTRAN frequency, as well as one or more physical cell identities and their associated system information. In this way,the UE can quickly access the target UTRAN without the need to perform the procedure for acquiring system information of the target UTRAN cell. Then, the UEcan directly initiate a CS service in the UTRAN cell.

Because flash CSFB complies with 3GPP Release 9, the networks and UEs involved must support 3GPP Release 9 or later.


This section describes the procedure for flash CSFB to UTRAN for mobile-originated calls, as shown in Figure 3-5.

Figure 3-5 Flash CSFB to UTRAN for mobile-originated calls





4. The eNodeB sends an RRC Connection Release message to instruct the UE to perform a redirection. The message contains information about a target UTRANfrequency, as well as one or more physical cell identities and their associated system information. Then, the eNodeB initiates an S1 UE context releaseprocedure.












The system information of the target cell is acquired during the RIM procedure. For details, see section 3.1.6 "RAN Information Management Procedure."


6. The UE initiates a CS call establishment procedure in the target UTRAN cell.


In a mobile-terminated call, the MSC sends a Paging Request message from the CS domain to the MME over the SGs interface. Then, the MME or the eNodeBinitiates a paging procedure for the UE, as shown in Figure 3-3. The subsequent steps are the same as the steps in the procedure for flash CSFB to UTRAN formobile-originated calls.


SMS services are unknown to the eNodeB because SMS messages are encapsulated in NAS messages. During interworking with the UTRAN, SMS messages areexchanged between the MME and the MSC over the SGs interface. Because a UE does not require fallback to the UTRAN to perform an SMS service, the SMSover SGs function can be used in a place covered only by the E-UTRAN.

As the SMS service is transparent to the eNodeB, the procedure is not described in this document. For details about the procedure, see section 8.2 in 3GPP TS23.272 V10.0.0.


The CSFB procedure for an emergency call is the same as the CSFB procedure for a normal mobile-originated voice service. The UE sends an RRC ConnectionRequest message over the Uu interface or the MME sends an S1-AP message, which contains an IE to inform the eNodeB of the service type. Emergency callstake precedence over other services in the eNodeB.

If PS handover is used for CSFB for emergency calls, the eNodeB does not restrict the cells in the handover restriction list when selecting the target cell. TheeNodeB sends the RNC a handover request with the IE CSFB high priority in the IE Source to Target Transparent Container. This request informs the RNC that aCSFB procedure is required for an emergency call. Upon receiving the information, the RNC preferentially processes this call when using related algorithms suchas admission control.

If redirection is used for CSFB for emergency calls, the RRC Connection Request message that the UE sends when accessing the UTRAN contains the indicationof an emergency call. The UTRAN will treat this call as a common CS emergency call.

For details about admission and preemption of emergency calls, see Emergency Call Feature Parameter Description.


After a UE initiates an LCS request, the MME performs an attach or combined TAU/LAU procedure to inform the UE of the LCS capability of the EPS. If the EPSdoes not support LCS, the UE falls back to the UTRAN to initiate LCS under the control of the EPS. The CSFB procedure is the same as the procedure for CSFB toUTRAN for mobile-originated calls.

If the UTRAN initiates an LCS request towards a UE camping on an E-UTRAN cell, the MSC sends an LCS indicator to the MME over the SGs interface. Then, theMME instructs the eNodeB to perform CSFB for the UE. The CSFB procedure is the same as the procedure for CSFB to UTRAN for mobile-terminated calls. TheUE performs the LCS service after the fallback to the UTRAN.

For details about the CSFB procedure for LCS, see section 8.3 in 3GPP TS 23.272 V10.0.0 and LCS Feature Parameter Description.


The RIM procedure, as shown in Figure 3-6, exchanges information between E-UTRAN and GERAN/UTRAN through the core networks. The procedure involves theeNodeB, MME, SGSN, and RNC/base station controller (BSC). Among these NEs, the MME and the SGSN transfer but do not resolve information.

Figure 3-6 RIM procedure

The RIM procedure supports two information exchange modes: Single Report and Multiple Report. In Single Report mode, the source sends a request, and thenthe target responds with a single report. In Multiple Report mode, the target responds with a report after receiving a request from the source, and it also sends areport to the source each time the system information changes. For details, see section 8c in 3GPP TS 48.018.

The Huawei eNodeB supports the two information exchange modes, and it acquires the system information of UTRAN cells during the RIM procedure. The MultipleReport mode is enabled or disabled by setting the ENodeBAlgoSwitch.RimSwitch parameter, while the Single Report mode is not configurable. The RIMprocedure and parameter settings are described as follows:

If a neighboring UTRAN cell supports the Multiple Report mode and UTRAN_RIM_SWITCH under the ENodeBAlgoSwitch.RimSwitch parameter is turned on,the RIM procedure in Multiple Report mode is performed as follows: After an external UTRAN cell corresponding to the neighboring UTRAN cell is configured, theeNodeB sends a request for system information to the neighboring UTRAN cell. After the neighboring UTRAN cell receives the request or the system informationchanges, this cell sends the system information to the eNodeB.

Whether an RIM procedure in Multiple Report mode can be triggered is based on the settings of the RIM switch and external UTRAN cells. For example, the RIM procedure cannot betriggered if the RIM switch is turned on but no external UTRAN cell is configured. If an external UTRAN cell has been configured, an RIM procedure is triggered each time the RIM switch isturned on.

If flash CSFB to UTRAN is enabled and UTRAN_RIM_SWITCH under the ENodeBAlgoSwitch.RimSwitch parameter is turned off, the eNodeB obtains thesystem information of the neighboring UTRAN cells by performing an RIM procedure in Single Report mode.

3.2 CSFB to GERAN

For details about engineering guidelines for CSFB to GERAN, see section 7.2 "Deploying CSFB to GERAN."


The combined EPS/IMSI attach procedure for CSFB to GERAN is the same as that for CSFB to UTRAN. For details, see section 3.1.1 "Combined EPS/IMSI AttachProcedure."


Based on the capabilities of UEs and networks, the following mechanisms are available for an eNodeB to perform CSFB to GERAN:

CSFB based on PS redirection

CSFB based on PS handover

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CSFB based on CCO/NACC

Flash CSFB

Table 3-2 lists the advantages and disadvantages of the preceding mechanisms in terms of impacts on the UEs, impacts on the networks, CS service access delay,and PS service interruption time.

Table 3-2 Comparison of fallback mechanisms for CSFB to GERAN

Fallback Mechanism Impact on theNetworks

Impact onthe UEs

CS Service AccessDelay

PS ServiceInterruption Time

CSFB based on PSredirection

Simple Simple Long Long

CSFB based on PShandover

Complex Complex Short Short

CSFB based onCCO/NACC

Medium Medium Medium Medium

Flash CSFB Medium Medium Short Medium

CSFB Based on PS Redirection

During CSFB based on PS redirection, the eNodeB receives a CS Fallback Indicator, and then it sends an RRC Connection Release message to release the UE.The message contains information about a target GERAN carrier frequency group, reducing the time for the UE to search for a target network. After selecting theGERAN, the UE acquires the system information of a GERAN cell. Then, the UE performs initial access to the cell to initiate a CS service. For the GERAN, the UE isa user that initially accesses the network.


This section describes the procedure for CSFB to GERAN based on PS redirection for mobile-originated calls, as shown in Figure 3-7.

Figure 3-7 CSFB to GERAN based on PS redirection for mobile-originated calls





4. The eNodeB sends an RRC Connection Release message to instruct the UE to perform a redirection. The message contains information about a target GERANcarrier frequency group. Then, the eNodeB initiates an S1 UE context release procedure.



6. If the UE or GERAN does not support dual transfer mode (DTM), in which CS and PS services run simultaneously, the ongoing PS services of the UE aresuspended.

7. The UE initiates a CS call establishment procedure in the target GERAN cell.


In a mobile-terminated call, the MSC sends a Paging Request message from the CS domain to the MME over the SGs interface. Then, the MME or the eNodeBinitiates a paging procedure for the UE, as shown in Figure 3-3. The subsequent steps are the same as the steps in the procedure for CSFB to GERAN based onPS redirection for mobile-originated calls.

CSFB Based on PS Handover

During CSFB based on PS handover, the UE is transferred from the E-UTRAN to the GERAN by performing a PS handover. It then initiates a CS service in theGERAN. If the GERAN or some GERAN-supporting UEs do not support DTM, the ongoing PS services must be suspended before the CS services can beestablished.


This section describes the procedure for CSFB to GERAN based on PS handover for mobile-originated calls, as shown in Figure 3-8.

Figure 3-8 CSFB to GERAN based on PS handover for mobile-originated calls

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4. The eNodeB initiates the preparation phase for a PS handover. If the preparation is successful, the eNodeB instructs the UE to perform a handover.

If DTM is not supported by the UE or GERAN, the ongoing PS services of the UE are suspended. Meanwhile, the SGSN updates the bearers towards the S-GW/P-GW.


5. After the handover, the UE may initiate a CS call establishment procedure with an LAU or combined RAU/LAU procedure in the GERAN.

6. The follow-up procedures are performed for the PS handover. These procedures include data forwarding, path switching, and RAU. This step is performedtogether with step 5.


In a mobile-terminated call, the MSC sends a Paging Request message from the CS domain to the MME over the SGs interface. Then, the MME or the eNodeBinitiates a paging procedure for the UE, as shown in Figure 3-3. The subsequent steps are the same as the steps in the procedure for CSFB to GERAN based onPS handover for mobile-originated calls.

CSFB Based on CCO/NACC

During CSFB based on CCO/NACC, the eNodeB receives a CS Fallback Indicator from the MME, and then it sends a Mobility From EUTRA Command message tothe UE over the Uu interface. The message contains information about the operating frequency, ID, and system information of a target GERAN cell. The UEsearches for a target cell based on the information it received, and then it performs initial access to the cell to initiate a CS service. If the GERAN or some GERAN-supporting UEs do not support DTM, the ongoing PS services must be suspended before the CS services can be established.


This section describes the procedure for CSFB to GERAN based on CCO/NACC for mobile-originated calls, as shown in Figure 3-9.

Figure 3-9 CSFB to GERAN based on CCO/NACC for mobile-originated calls














4. The eNodeB sends a Mobility From EUTRA Command message over the Uu interface to indicate the operating frequency and ID of the target GERAN cell. If thesource cell has the system information of the target cell, the system information is also carried in the message.



5. The MME initiates an S1 UE context release procedure.

6. The UE initiates an LAU, a combined RAU/LAU, or both an RAU and an LAU in the target cell.

7. If DTM is not supported by the UE or GERAN, the ongoing PS services of the UE are suspended.



In a mobile-terminated call, the MSC sends a Paging Request message from the CS domain to the MME over the SGs interface. Then, the MME or the eNodeBinitiates a paging procedure for the UE, as shown in Figure 3-3. The subsequent steps are the same as the steps in the procedure for CSFB to GERAN based onCCO/NACC for mobile-originated calls.

Flash CSFB

During the flash CSFB procedure, the eNodeB receives a CS Fallback Indicator, and then it sends an RRC Connection Release message to release the UE. Themessage contains information about a target GERAN carrier frequency group, as well as one or more physical cell identities and their associated systeminformation. The UE searches for a target cell based on the information it received, and then it performs initial access to the cell to initiate a CS service. If theGERAN or some GERAN-supporting UEs do not support DTM, the ongoing PS services must be suspended before the CS services can be established.

Because flash CSFB complies with 3GPP Release 9, the networks and UEs involved must support 3GPP Release 9 or later.


This section describes the procedure for flash CSFB to GERAN for mobile-originated calls, as shown in Figure 3-10.

Figure 3-10 Flash CSFB to GERAN for mobile-originated calls





4. The eNodeB sends an RRC Connection Release message to instruct the UE to perform a redirection. The message contains information about a target GERANcarrier frequency group, as well as one or more physical cell identities and their associated system information. Then, the eNodeB initiates an S1 UE contextrelease procedure.




6. If DTM is not supported by the UE or GERAN, the ongoing PS services of the UE are suspended.



In a mobile-terminated call, the MSC sends a Paging Request message from the CS domain to the MME over the SGs interface. Then, the MME or the eNodeBinitiates a paging procedure for the UE, as shown in Figure 3-3. The subsequent steps are the same as the steps in the procedure for flash CSFB to GERAN formobile-originated calls.


SMS services are unknown to the eNodeB because SMS messages are encapsulated in NAS messages. During interworking with the GERAN, SMS messages areexchanged between the MME and the MSC over the SGs interface. Because a UE does not require fallback to the GERAN to perform an SMS service, the SMSover SGs function can be used in a place covered only by the E-UTRAN.

As the SMS service is transparent to the eNodeB, the procedure is not described in this document. For details about the procedure, see section 8.2 in 3GPP TS23.272 V10.0.0.


The CSFB procedure for an emergency call is the same as the CSFB procedure for a normal mobile-originated voice service. The UE sends an RRC ConnectionRequest message over the Uu interface or the MME sends an S1-AP message, which contains an IE to inform the eNodeB of the service type. Emergency calls


















take precedence over other services in the eNodeB.

If PS handover is used for CSFB for emergency calls, the eNodeB does not restrict the cells in the handover restriction list when selecting the target cell.

If redirection is used for CSFB for emergency calls, the Channel Request message that the UE sends when accessing the GERAN contains the indication of anemergency call. The GERAN will treat this call as a common CS emergency call.

For details about admission and preemption of emergency calls, see Emergency Call Feature Parameter Description.


After a UE initiates an LCS request, the MME performs an attach or combined TAU/LAU procedure to inform the UE of the LCS capability of the EPS. If the EPSdoes not support LCS, the UE falls back to the GERAN to initiate LCS under the control of the EPS. The CSFB procedure is the same as the procedure for CSFBto GERAN for mobile-originated calls.

If the GERAN initiates an LCS request towards a UE camping on an E-UTRAN cell, the MSC sends an LCS indicator to the MME over the SGs interface. Then, theMME instructs the eNodeB to perform CSFB for the UE. The CSFB procedure is the same as the procedure for CSFB to GERAN for mobile-terminated calls. TheUE performs the LCS service after the fallback to the GERAN.

For details about the CSFB procedure for LCS, see section 8.3 in 3GPP TS 23.272 V10.0.0 and LCS Feature Parameter Description.


The RIM procedure for CSFB to GERAN is the same as that for CSFB to UTRAN. For details, see section 3.1.6 "RAN Information Management Procedure."

The Huawei eNodeB supports two information exchange modes, and it acquires the system information of GERAN cells during the RIM procedure. The MultipleReport mode is enabled or disabled by setting the ENodeBAlgoSwitch.RimSwitch parameter, while the Single Report mode is not configurable. The RIMprocedure and parameter settings are described as follows:

If a neighboring GERAN cell supports the Multiple Report mode and GERAN_RIM_SWITCH under the ENodeBAlgoSwitch.RimSwitch parameter is turned on,the RIM procedure in Multiple Report mode is performed as follows: After an external GERAN cell corresponding to the neighboring GERAN cell is configured, theeNodeB sends a request for system information to the neighboring GERAN cell. After the neighboring GERAN cell receives the request or the system informationchanges, this cell sends the system information to the eNodeB.

Whether an RIM procedure in Multiple Report mode can be triggered is based on the settings of the RIM switch and external GERAN cells. For example, the RIM procedure cannot betriggered if the RIM switch is turned on but no external GERAN cell is configured. If an external GERAN cell has been configured, an RIM procedure is triggered each time the RIM switch isturned on.

If flash CSFB to GERAN or CCO/NACC is enabled but GERAN_RIM_SWITCH under the ENodeBAlgoSwitch.RimSwitch parameter is turned off, the eNodeBobtains the system information of the neighboring GERAN cells by performing the RIM procedure in Single Report mode.

3.3 CSFB to CDMA2000 1xRTT

Huawei eNodeBs support CSFB to CDMA2000 1xRTT based on PS redirection.

For details about engineering guidelines for CSFB to CDMA2000 1xRTT, see section 7.3 "Deploying CSFB to CDMA2000 1xRTT."

3.3.1 Preregistration Procedure

To perform CSFB to CDMA2000 1xRTT from an E-UTRAN cell, a 1xCS CSFB-capable UE must initiate preregistration with the CDMA2000 1xRTT CS networkthrough the E-UTRAN. However, the UE can initiate the preregistration only if the E-UTRAN supports CSFB to CDMA2000 1xRTT as indicated in the systeminformation block type 8 (SIB8) broadcast by eNodeBs. The preregistration procedure is shown in Figure 3-11.

Figure 3-11 Preregistration procedure for CSFB to CDMA2000 1xRTT


1. The UE is attached to the E-UTRAN. For details about the attach procedure, see section 5.3.2 in 3GPP TS 23.401 V9.2.0.

2. After receiving the SIB8, the UE decides to initiate preregistration with the CDMA2000 1xRTT CS network. Meanwhile, the UE sends a CSFB ParametersRequest CDMA2000 message to the eNodeB to obtain preregistration-related parameters.

3. The UE sends a 1xRTT CS Registration Request message through the E-UTRAN. The eNodeB transmits the request in a UL S1 cdma2000 Tunnelling messageto the MME, with the IE CDMA2000 Sector ID in the message containing the IE CDMA2000 Reference Cell ID. Based on the received CDMA2000 Reference CellID, the MME selects a 1xCS IWS (short for Circuit Switched Fallback Interworking Solution Function for 3GPP2 1xCS). The MME sends the 1xCS IWS anS102/A21-1x Air Interface Signaling message containing the IEs IMSI and 1xCS message.

4. The 1xCS IWS performs the preregistration as specified in 3GPP2 A.S0008.

5. The 1xCS IWS responds to the UE with a 1xRTT CS Registration Response message. The message is carried in the following messages:

− S102 Direct Transfer

− DL S1 cdma2000 Tunnelling

− DL Information Transfer

3.3.2 CSFB Procedure for Mobile-originated Calls

This section describes the procedure for CSFB to CDMA2000 1xRTT for mobile-originated calls, as shown in Figure 3-12.

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Figure 3-12 CSFB to CDMA2000 1xRTT for mobile-originated calls



2. The MME sends an S1-AP Request message containing a CS Fallback Indicator, instructing the eNodeB to initiate a CSFB procedure.


4. The eNodeB sends an RRC Connection Release message that contains the IE redirectedCarrierInfo, instructing the UE to perform a redirection to the 1xRTT CSdomain.

5. The eNodeB sends the MME an S1 UE Context Release Request message containing the IE Cause with the value of "CS Fallback triggered".

6. The UE initiates a CS call establishment procedure to make a call in the 1xRTT CS domain, as specified in 3GPP2 A.S0013.

When the CS call is complete, the UE performs a cell reselection to return to the E-UTRAN cell.

3.3.3 CSFB Procedure for Mobile-terminated Calls

This section describes the procedure for CSFB to CDMA2000 1xRTT for mobile-terminated calls, as shown in Figure 3-13.

Figure 3-13 CSFB to CDMA2000 1xRTT for mobile-terminated calls


1. The 1xRTT MSC sends a Paging Request message to the 1xCS IWS. The message also contains the calling number, if any. Then, the 1xCS IWS transmits thepaging request to the MME through the S102 tunnel. If the UE is in idle mode, the MME sends a network-initiated service request, which enables the UE totransit to active mode. The MME sends the paging request in DL S1 cdma2000 Tunnelling and DL Information Transfer messages to the UE.


3. The MME sends an S1-AP Request message containing a CS Fallback Indicator, instructing the eNodeB to initiate a CSFB procedure.


5. The eNodeB sends an RRC Connection Release message that contains the IE redirectedCarrierInfo, instructing the UE to perform a redirection to the 1xRTT CSdomain.

6. The eNodeB sends the MME an S1 UE Context Release Request message containing the IE Cause with the value of "CS Fallback triggered".

7. The UE sends a 1xRTT Paging Response message from the 1xRTT CS domain.

8. The UE initiates a CS call establishment procedure to receive a call in the 1xRTT CS domain, as specified in 3GPP2 A.S0013.








When the CS call is complete, the UE performs a cell reselection to return to the E-UTRAN cell.


During the CSFB procedure, the SMS messages are exchanged between the UE and the eNodeB over the Uu interface, between the eNodeB and the MME overthe S1 interface, and between the MME and the 1xCS IWS over the S102 interface. The UE does not require fallback to the CDMA2000 1xRTT network to performthe SMS service.


If CSFB to CDMA2000 1xRTT is required for an emergency call, the UE sends the MME an NAS message Extended Service Request containing the IE ServiceType, indicating an incoming emergency call. Then, the MME sends the eNodeB an S1 UE Context Modification Request message containing a CS FallbackIndicator, indicating that the high-priority emergency call requires CSFB to CDMA2000 1xRTT. Upon receiving the information, the eNodeB preferentially processesthis call.

4 CSFB at the eNodeB

This chapter describes the CSFB procedure performed by Huawei eNodeB and provides the setting descriptions for the parameters involved. Figure 4-1 shows theCSFB procedure performed by the eNodeB.

Figure 4-1 CSFB procedure performed by the eNodeB

The CSFB procedure consists of the following phases:

1. Triggering phase

After receiving a CS Fallback Indicator from the MME, the eNodeB decides whether to perform CSFB in the form of a blind handover based on the UE capabilitiesand the setting of the blind handover switch. Compared with measurement-based handovers, blind handovers have shorter access delays but a lower handoversuccess rate.

2. Measurement phase

The eNodeB delivers the inter-RAT measurement configuration to the UE, and the UE performs inter-RAT measurements as instructed.

3. Decision phase

The eNodeB evaluates the measurement results and generates a list of candidate cells.

4. Execution phase

The eNodeB executes CSFB to enable the UE to initiate the CS service in the target cell.

To simplify statements, "handover" mentioned in this chapter is a generic term for both normal handover and redirection.

4.1 Triggering Phase of CSFB

4.1.1 Choosing Between a Blind Handover and a Measurement-based Handover

After a UE initiates a CS service in an E-UTRAN cell, the MME sends the eNodeB an S1-AP Request message that contains a CS Fallback Indicator, notifying theeNodeB that the UE should be transferred to the target network. The target networks to which CSFB can be performed are specified by theENodeBAlgoSwitch.HoAlgoSwitch parameter.

After receiving the CS Fallback Indicator, the eNodeB checks the blind-handover switch setting and UE capabilities for each RAT and performs accordingly:

If the BlindHoSwitch check box under the ENodeBAlgoSwitch.HoModeSwitch parameter is cleared, blind handovers are prohibited. Under this condition, if theUE is capable of measuring an RAT, the eNodeB delivers the inter-RAT measurement configuration to the UE, instructing the UE to perform measurements onthis RAT.

If the BlindHoSwitch check box under the ENodeBAlgoSwitch.HoModeSwitch parameter is cleared and the UE is incapable of measuring an RAT, the eNodeBdirectly performs CSFB in the form of a blind handover.

If the BlindHoSwitch check box under the ENodeBAlgoSwitch.HoModeSwitch parameter is selected, the eNodeB directly performs CSFB in the form of a blindhandover.

If the PS handover switch is turned on, it is recommended that the blind handover switch be turned off to increase the CSFB success rate. The UtranPsHoSwitchand GeranPsHoSwitch options under the ENodeBAlgoSwitch.HoModeSwitch parameter specify whether to enable PS handover to UTRAN and GERAN,respectively.

4.1.2 Selecting Frequencies to Measure or a Target Cell (Without an LAI)

If the eNodeB has not received any LAIs from the MME, it performs blind handovers and measurement-based handovers differently.

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In a Blind Handover

If LOFD-001078 E-UTRAN to UTRAN CS/PS Steering is disabled or UtranFreqLayerBlindSwitch is turned off, the eNodeB selects a target cell for the blindhandover by taking both the following priorities into consideration: the blind-handover priority of the target RAT and the blind-handover priority of the specified cell.The eNodeB selects an RAT with the highest priority first and then selects a cell with the highest priority in this RAT. If CSFB is triggered for an emergency call, anLCS-supporting RAT takes precedence over a non-LCS-supporting RAT.

UtranFreqLayerBlindSwitch is a switch under the ENodeBAlgoSwitch.FreqLayerSwtich parameter.

The priorities of RATs used in blind handovers for CSFB are specified by the CSFallBackBlindHoCfg.InterRatHighestPri,CSFallBackBlindHoCfg.InterRatSecondPri, and CSFallBackBlindHoCfg.InterRatLowestPri parameters.

The blind-handover priority of an inter-RAT neighboring cell is specified as follows:

Neighboring UTRAN cell: by the UtranNCell.BlindHoPriority parameter

Neighboring GERAN cell: by the GeranNcell.BlindHoPriority parameter

Neighboring CDMA2000 1xRTT cell: by the Cdma20001XRTTNcell.BlindHoPriority parameter

If LOFD-001078 E-UTRAN to UTRAN CS/PS Steering is enabled and UtranFreqLayerBlindSwitch is turned on, the eNodeB first selects an RAT with the highestblind-handover priority. If the selected RAT is UTRAN, the eNodeB selects a target cell for the blind handover as follows:

If there are UE-supported frequencies with the high CS service priority, the eNodeB selects the cell with the highest blind-handover priority among the cells onthese frequencies.

The CS service priorities are specified by the UtranNFreq.CsPriority parameter.

If there are not frequencies with the high CS service priority or the UE does not support frequencies with the high CS service priority, the eNodeB selects the cellwith the highest blind-handover priority among the cells on the frequencies with the low CS service priority.

In a Measurement-based Handover

If LOFD-001078 E-UTRAN to UTRAN CS/PS Steering is disabled or UtranFreqLayerMeasSwitch is turned off, the eNodeB selects a UE-supported RAT andfrequency in the configurations of neighboring frequencies and neighboring cells, and then includes the information in the measurement configuration to the UE.UtranFreqLayerMeasSwitch is a switch under the ENodeBAlgoSwitch.FreqLayerSwtich parameter.

If LOFD-001078 E-UTRAN to UTRAN CS/PS Steering is enabled and UtranFreqLayerMeasSwitch is turned on, measurements vary as follows:

If there are UE-supported frequencies with the high CS service priority, measurements will be performed on frequencies with the high CS service priority, but noton frequencies with the low CS service priority even after measurements fail for the frequencies with the high CS service priority.

If there are not frequencies with the high CS service priority, the UE does not support the frequencies with the high CS service priority, or no cell in theneighboring UTRAN cell list operates on the frequencies with the high CS service priority, then measurements will be performed on frequencies with the low CSservice priority.

UtranFreqLayerMeasSwitch controls only UTRAN frequencies but not GERAN frequencies, and therefore the eNodeB decides whether to instruct the UE to perform measurements onlybased on whether the UE supports the GERAN and GERAN frequencies.

4.1.3 Selecting Frequencies to Measure or a Target Cell (With an LAI)

If the MME delivers an LAI to the eNodeB, the eNodeB also takes this LAI into account, in addition to the principles described in the preceding section. This sectiondescribes the LAI-based principles.

In a Blind Handover

The eNodeB checks all inter-RAT neighboring cells of the cell serving the UE and considers the following three sets (in descending order of priority) based on theLAI:

Set 1 consists of neighboring cells with the same PLMN ID and LAC as those indicated in the received LAI.

Set 2 consists of neighboring cells with the same PLMN ID but different LACs as those indicated in the received LAI.

Set 3 consists of neighboring cells located in the same PLMN as the serving PLMN of the UE.

The eNodeB selects the CSFB target cell from the set that has the highest priority among all non-empty sets. If there are multiple neighboring cells in the highest-priority non-empty set, the eNodeB selects the neighboring cell with the highest blind handover priority as the CSFB target cell. If the three sets are all empty, theeNodeB delivers the inter-RAT measurement configuration to the UE. This CSFB will be performed in the form of a measurement-based handover.

If the neighboring GERAN and UTRAN cells have the same PLMN ID as that indicated in the received LAI, the eNodeB selects the RAT with the higher blind-handover priority as the target RAT for CSFB. If UTRAN is selected, LOFD-001078 E-UTRAN to UTRAN CS/PS Steering is enabled, andUtranFreqLayerMeasSwitch is turned on, the eNodeB selects the target cell by performing the following steps:

1. Listing neighboring cells with the same PLMN ID as that indicated in the received LAI.

2. Choosing neighboring cells with high CS service priorities among the cells listed in 1.

3. Preferentially selecting neighboring cells with the same LAC as that indicated in the received LAI.

If there are multiple cells after the preceding steps, the eNodeB proceeds with the procedure as described in the case of a blind handover.

In a Measurement-based Handover

The eNodeB delivers information about an inter-RAT frequency in the measurement configuration to the UE if both the following conditions are met:

The PLMN ID of any inter-RAT neighboring cell on this frequency is the same as the PLMN indicated in the LAI.

The UE supports this RAT.

The UE is capable of measuring this frequency.

Note that only the frequencies that the UE is capable of measuring are delivered in the measurement configuration.

If the eNodeB fails to select the frequencies and target cells according to the LAI delivered by the MME, the eNodeB proceeds with the procedure as described in section 4.1.2 "SelectingFrequencies to Measure or a Target Cell (Without an LAI)."

4.2 Measurement Phase of CSFB

4.2.1 Measurement Configuration

The measurement configuration procedure and measurement gap configuration for CSFB to UTRAN/GERAN/CDMA2000 1xRTT are the same as those for inter-RAT handovers. For details, see Mobility Management in Connected Mode Feature Parameter Description.

4.2.2 Measurement Reporting

CSFB is triggered by event B1, which is reported in event-triggered periodical reporting mode.

The triggering of event B1 indicates that the signal quality is higher than a specified threshold in at least one neighboring cell. Section 5.5.4.7 in 3GPP TS 36.331V10.0.0 defines the entering and leaving conditions of event B1 as follows:

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http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/CSFallBackBlindHoCfg-InterRatHighestPri.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/CSFallBackBlindHoCfg-InterRatSecondPri.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/CSFallBackBlindHoCfg-InterRatLowestPri.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/UtranNCell-BlindHoPriority.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/GeranNcell-BlindHoPriority.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/Cdma20001XRTTNcell-BlindHoPriority.html








Entering condition: Mn + Ofn - Hys > Thresh

Leaving condition: Mn + Ofn + Hys < Thresh

where

Mn is the measurement result of the neighboring cell.

Ofn is the frequency-specific offset for the frequency of the neighboring cell. It is contained in the associated measurement object IE in the measurementconfiguration.

Hys is the hysteresis for event B1. The hysteresis values for CSFB to UTRAN, GERAN, and CDMA2000 1xRTT are contained in the measurement configuration.

Thresh is the threshold for event B1. The values of Thresh are set based on the measurement quantities for each RAT, as follows:

− The received signal code power (RSCP) threshold for CSFB to UTRAN is specified by CSFallBackHo.CsfbHoUtranB1ThdRscp.

− The Ec/No threshold for CSFB to UTRAN is specified by CSFallBackHo.CsfbHoUtranB1ThdEcn0.

− The received signal strength indicator (RSSI) threshold for CSFB to GERAN is specified by CSFallBackHo.CsfbHoGeranB1Thd.

− The pilot strength threshold for CSFB to CDMA2000 1xRTT is specified by CSFallBackHo.CsfbHoCdmaB1ThdPS.

If the entering condition of event B1 is continuously met during a period known as time-to-trigger, the UE reports information about the cells that meet the conditionto the eNodeB. The time-to-trigger for event B1 related to CS fallback to UTRAN/GERAN/CDMA2000 1xRTT is specified by theCSFallBackHo.CsfbHoUtranTimeToTrig, CSFallBackHo.CsfbHoGeranTimeToTrig, and CSFallBackHo.CsfbHoCdmaTimeToTrig parameters, respectively.

The following parameters related to event B1 for CSFB are the same as those related to event B1 for inter-RAT handovers:

Frequency-specific offset for the frequency of the neighboring cell

Hysteresis

Reporting interval

Maximum number of cells contained in one report

Number of periodic reports

For details, see Mobility Management in Connected Mode Feature Parameter Description.

4.3 Decision Phase of CSFB

In the decision phase of a measurement-based handover for CSFB, the eNodeB checks the measurement results reported by the UE. Based on the result, theeNodeB determines whether CSFB is to be initiated and, if so, determines the target cell for the CSFB.

After having received the B1 measurement reports for CSFB, the way in which the eNodeB determines the target cell for the CSFB varies depending on whether anLAI has been received, as follows:

If no LAI has been received, the eNodeB generates a list of candidate cells for CSFB based on the received reports. It selects the cell with the highest signalquality from this list.

If an LAI has been received, the eNodeB considers the candidate cells in sets 1, 2, and 3. It sorts cells in each list by signal quality, and it selects a target cell fromthe three lists in descending order of priority. For details about sets 1, 2, and 3, see section 4.1.3 "Selecting Frequencies to Measure or a Target Cell (With anLAI)."

4.4 Execution Phase of CSFB

Figure 4-2, Figure 4-3, and Figure 4-4 show the procedures for executing CSFB to GERAN, UTRAN, and CDMA2000 1xRTT, respectively. Parameters in thefigures are specified by switches under the ENodeBAlgoSwitch.HoModeSwitch parameter. The eNodeB selects a CSFB mechanism based on both the UEcapability and mechanism priority.

Figure 4-2 Procedure for executing CSFB to GERAN

Figure 4-3 Procedure for executing CSFB to UTRAN

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http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/CSFallBackHo-CsfbHoUtranB1ThdRscp.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/CSFallBackHo-CsfbHoUtranB1ThdEcn0.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/CSFallBackHo-CsfbHoGeranB1Thd.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/CSFallBackHo-CsfbHoCdmaB1ThdPs.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/CSFallBackHo-CsfbHoUtranTimeToTrig.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/CSFallBackHo-CsfbHoGeranTimeToTrig.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/CSFallBackHo-CsfbHoCdmaTimeToTrig.html










Figure 4-4 Procedure for executing CSFB to CDMA2000 1xRTT

4.5 CSFB Exception Handling

The eNodeB starts a timer after receiving the CS Fallback Indicator. If the UE remains in the coverage of the eNodeB when the timer expires, the eNodeB performsa blind redirection procedure for CSFB. Currently the timer is set to a fixed value of 4 seconds.

If the eNodeB determines to perform CSFB in the form of a blind handover but the target candidate cell with the highest blind-handover priority fails the handoverpreparation, the eNodeB selects another cell based on the blind-handover priorities in descending order. The eNodeB can initiate handover attempts to a maximumof eight candidate cells that are configured with blind-handover priorities. If no candidate cell meets the conditions for a blind handover, the eNodeB performs ablind redirection for CSFB.



5 Related Features

5.1 Features Related to LOFD-001033 CS Fallback to UTRAN

Required Features

This feature requires LOFD-001019 PS Inter-RAT Mobility between E-UTRAN and UTRAN.

Mutually Exclusive Features

When a UE initiates a CSFB request, the eNodeB cannot determine, according to 3GPP Release 9 specifications, whether the target inter-RAT network is aCDMA2000 1xRTT network or a GERAN/UTRAN. To prevent this problem, CSFB to GERAN/UTRAN cannot be enabled together with CSFB to CDMA2000 1xRTT.

This feature does not work with the following features:


LOFD-001090 Enhanced CS Fallback to CDMA2000 1xRTT

Affected Features

None

5.2 Features Related to LOFD-001034 CS Fallback to GERAN

Required Features

This feature requires LOFD-001020 PS Inter-RAT Mobility between E-UTRAN and GERAN.






Affected Features

None

5.3 Features Related to LOFD-001035 CS Fallback to CDMA2000 1xRTT

Required Features

This feature requires LOFD-001021 PS Inter-RAT Mobility between E-UTRAN and CDMA2000.




LOFD-001033 CS Fallback to UTRAN

LOFD-001034 CS Fallback to GERAN

Affected Features

None

5.4 Features Related to LOFD-001052 Flash CS Fallback to UTRAN

Required Features

This feature requires LOFD-001033 CS Fallback to UTRAN.






Affected Features

If the handover switch is turned on for LOFD-001019 PS Inter-RAT Mobility between E-UTRAN and UTRAN, and UEs support mobility from the E-UTRAN to theUTRAN, LOFD-001052 Flash CS Fallback to UTRAN does not take effect. That is, if handover to UTRAN is enabled and UEs are capable of such handovers, allinter-RAT procedures to the UTRAN including CSFB will preferentially be performed based on handovers.

5.5 Features Related to LOFD-001053 Flash CS Fallback to GERAN

Required Features

This feature requires LOFD-001034 CS Fallback to GERAN.






Affected Features

If the handover switch is turned on for LOFD-001020 PS Inter-RAT Mobility between E-UTRAN and GERAN, and UEs support mobility from the E-UTRAN to theGERAN, LOFD-001053 Flash CS Fallback to GERAN does not take effect. That is, if handover to GERAN is enabled and UEs are capable of such handovers, allinter-RAT procedures to the GERAN including CSFB will preferentially be performed based on handovers.

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5.6 Features Related to LOFD-001068 CS Fallback with LAI to UTRAN

Required Features

This feature requires LOFD-001033 CS Fallback to UTRAN.






Affected Features

None

5.7 Features Related to LOFD-001069 CS Fallback with LAI to GERAN

Required Features

This feature requires LOFD-001034 CS Fallback to GERAN.






Affected Features

None

5.8 Features Related to LOFD-001078 E-UTRAN to UTRAN CS/PS Steering

Required Features

LOFD-001078 E-UTRAN to UTRAN CS/PS Steering requires the LOFD-001019 PS Inter-RAT Mobility between E-UTRAN and UTRAN and LOFD-001033 CSFallback to UTRAN features to be activated.


None

Affected Features

None

6 Network Impact

6.1 LOFD-001033 CS Fallback to UTRAN

System Capacity

In essence, CSFB provides CS service access for E-UTRAN UEs. Considering that the number of UEs that request CS services within an area is relatively stableand is not affected by EPS deployment, CSFB has no impact on the total number of UEs that request CS services within a network.

CSFB mechanisms affect signaling overhead as follows:

If redirection is used as the CSFB mechanism, no extra signaling message is required for the UTRAN because each CSFB procedure is equivalent to the initiationof a new CS service. The EPS does not need to interact with the target network, and the corresponding signaling overhead is negligible.

If PS handover is used as the CSFB mechanism, extra signaling messages are required from each NE for the request, preparation, and execution of eachhandover. However, from the perspective of traffic statistics, the number of UEs that initiate CS services per second per cell during peak hours is far below cellcapacity. Therefore, signaling overhead caused by PS handovers is low.

Load-based CSFB to UTRAN prevents PS handover preparation failure caused by UTRAN cell congestion, because the eNodeB selects a target cell based on theUTRAN cell load status. This increases system capacity.

Network Performance

CSFB affects the access success rate as follows:

If redirection is used as the CSFB mechanism, each CSFB procedure is equivalent to the initiation of a new CS service. Therefore, the access success rate forCSFB UEs is theoretically the same as that for normal CS UEs in the UTRAN.

If PS handover is used as the CSFB mechanism, the access success rate for CSFB UEs depends on the success rate of handovers to the target RAT. Handover-triggered CS service access has a higher requirement for signal quality compared with normal CS service access. Therefore, the access success rate for CSFBUEs is a little lower than that for normal CS UEs in the UTRAN.

Load-based CSFB to UTRAN prevents PS handover preparation failure caused by UTRAN cell congestion, because the eNodeB selects a target cell based on theUTRAN cell load status. This decreases the CSFB delay.


System Capacity


CSFB mechanisms affect signaling overhead as follows:

If redirection or CCO without NACC is used as the CSFB mechanism, no extra signaling message is required for the GERAN because each CSFB procedure isequivalent to the initiation of a new CS service. The EPS does not need to interact with the target network. Therefore, signaling overhead is negligible.

If CCO with NACC is used as the CSFB mechanism, extra signaling messages are required only during eNodeB deployment. Afterward, signaling overhead isnegligible because of infrequent system information updates.

If PS handover is used as the CSFB mechanism, extra signaling messages are required from each NE for the request, preparation, and execution of eachhandover. However, from the perspective of traffic statistics, the number of UEs that initiate CS services per second per cell during peak hours is far below cell

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capacity. Therefore, signaling overhead caused by PS handovers is low.

Network Performance


If redirection or CCO/NACC is used as the CSFB mechanism, each CSFB procedure is equivalent to the initiation of a new CS service. Therefore, the accesssuccess rate for CSFB UEs is theoretically the same as that for normal CS UEs in the GERAN.

If PS handover is used as the CSFB mechanism, the access success rate for CSFB UEs depends on the success rate of handovers to the target RAT. Handover-triggered CS service access has a higher requirement for signal quality compared with normal CS service access. Therefore, the access success rate for CSFBUEs is a little lower than that for normal UEs in the GERAN.


System Capacity


Network Performance


If redirection or CCO/NACC is used as the CSFB mechanism, each CSFB procedure is equivalent to the initiation of a new CS service. Therefore, the accesssuccess rate for CSFB UEs is theoretically the same as that for normal CS UEs in the CDMA2000.

If PS handover is used as the CSFB mechanism, the access success rate for CSFB UEs depends on the success rate of handovers to the target RAT. Handover-triggered CS service access has a higher requirement for signal quality compared with normal CS service access. Therefore, the access success rate for CSFBUEs is a little lower than that for normal UEs in the CDMA2000.

6.4 LOFD-001052 Flash CS Fallback to UTRAN

System Capacity


Flash CSFB affects signaling overhead as follows:

Extra signaling messages are required only during eNodeB deployment. Afterward, signaling overhead is negligible because of infrequent system informationupdates.

Network Performance

Flash CSFB affects the access success rate as follows:

Each flash CSFB procedure is equivalent to the initiation of a new CS service. Therefore, the access success rate for CSFB UEs is theoretically the same as thatfor normal CS UEs in the UTRAN.

The RRC connection setup success rate may decrease slightly for the UTRAN. The uplink interference information contained in SIB7 in the UTRAN updatesfrequently. The RNC cannot update the uplink interference information in the system information sent to the LTE network based on SIB7 in the UTRAN.Therefore, the uplink interference information contained in SIB7 in the LTE network is a default value (–105 dBm). If the actual uplink interference in the UTRANis greater than –105 dBm, the transmit power on UEs' physical random access channel (PRACH) increases and the RRC connection setup success rate maydecrease.

Flash CSFB to UTRAN decreases the CSFB delay by up to 1.28s because UEs obtain information about the target UTRAN cell for redirection before RRCconnections to the LTE network are released.

6.5 LOFD-001053 Flash CS Fallback to GERAN

System Capacity


Flash CSFB affects signaling overhead as follows:

Extra signaling messages are required only during eNodeB deployment. Afterward, signaling overhead is negligible because of infrequent system informationupdates.

Network Performance

If flash CSFB is used as the CSFB mechanism, each CSFB procedure is equivalent to the initiation of a new CS service. Therefore, the access success rate forCSFB UEs is theoretically the same as that for normal CS UEs in the GERAN.

Flash CSFB to GERAN decreases the CSFB delay by up to 2s because UEs obtain information about the target GERAN cell for redirection before RRCconnections to the LTE network are released.

6.6 LOFD-001068 CS Fallback with LAI to UTRAN

System Capacity

No impact.

Network Performance

CSFB with LAI ensures that a UE can fall back to the CS network to which the UE has attached. This prevents CSFB failure or long delay caused by incorrect targetRAT selection and increases the CSFB success rate.

6.7 LOFD-001069 CS Fallback with LAI to GERAN

System Capacity

No impact.

Network Performance

CSFB with LAI ensures that a UE can fall back to the CS network to which the UE has attached. This prevents CSFB failure or long delay caused by incorrect targetRAT selection and increases the CSFB success rate.

6.8 LOFD-001078 E-UTRAN to UTRAN CS/PS Steering

System Capacity

No impact.

Network Performance

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E-UTRAN to UTRAN CS/PS Steering enables an eNodeB to include only UTRAN frequencies with a high CS service priority in measurement configurations. Thisprevents redundant measurements, reduces the measurement time, and decreases end-to-end CSFB delay.

If the CS service priorities of UTRAN frequencies configured on the eNodeB are consistent with those configured at the UTRAN side, E-UTRAN to UTRAN CS/PSSteering prevents further intra-UTRAN handovers for service steering. This improves user experience.

7 Engineering Guidelines

7.1 Deploying CSFB to UTRAN

7.1.1 When to Use CSFB to UTRAN

Use LOFD-001033 CS Fallback to UTRAN in the initial phase of LTE network deployment when both of the following conditions are met:

The operator owns a mature UTRAN network.

The LTE network does not provide VoIP services, or UEs in the LTE network do not support VoIP services.

For policies on whether to use PS handover or PS redirection for CSFB, see Mobility Management in Connected Mode Feature Parameter Description. If theUTRAN cell and E-UTRAN cell cover the same area, or the UTRAN cell provides better coverage than the E-UTRAN cell, use CSFB based on blind handover todecrease the CSFB delay.


Collect the operating frequencies, coverage areas, and configurations of the E-UTRAN and UTRAN cells. Information about coverage areas includes engineeringparameters of sites (such as latitude and longitude), TX power of cell reference signals (RSs), and neighbor relationship configurations.

Collect the versions and configurations of the NEs in the E-UTRAN, UTRAN, and core networks, and ensure that they all support CSFB. Table 7-1 describes therequirements of CSFB to UTRAN for the core networks.

Table 7-1 Requirements of CSFB to UTRAN for the core networks

NE Description

MME Supports:

SGs interface to the MSC

LAI selection based on the TAI of the serving cell

MSC-initiated paging

PLMN selection and reselection

Combined EPS/IMSI attach, combined EPS/IMSI detach, and combined TAU/LAU

Routing of CS signaling messages

SMS over SGs

MSC Supports:


SMS over SGs

Paging message forwarding over the SGs interface

SGSN Does not activate ISR during the combined RAU/LAU procedure initiated by the UE.

Collect the following information about the UEs supporting UMTS and LTE on the live network:

− Supported frequency bands

− Whether the UEs support redirection from E-UTRAN to UTRAN

− Whether the UEs support PS handover from E-UTRAN to UTRAN

− Whether the UEs support UTRAN measurements

This information is used to configure neighboring UTRAN cells and to determine whether to perform CSFB based on handover or redirection. For details, seeMobility Management in Connected Mode Feature Parameter Description.


Requirements for the Operating Environment

For this feature, the eNodeB must collaborate with the core-network equipment.

If the core-network equipment is provided by Huawei, the version must be SAE1.2 or later.

If the core-network equipment is provided by another vendor, check with the vendor whether the equipment supports this feature.

Requirements for Licenses

Operators must purchase and activate the following license.

Table 7-2 License control item for CSFB to UTRAN

Feature License Control Item Name

LOFD-001033 CS Fallback to UTRAN CS Fall Back to UTRAN


This section describes generic data and scenario-specific data to be collected. Generic data is necessary for all scenarios and must always be collected. Scenario-specific data is collected only when necessary for a specific scenario.

There are three types of data sources:

Network plan (negotiation required): Parameters are planned by operators and negotiated with the EPC or peer transmission equipment.

Network plan (negotiation not required): Parameters are planned and set by operators.

User-defined: Parameters are set as required by users.

Generic Data

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Before configuring CSFB to UTRAN, collect the data related to neighbor relationships with UTRAN cells. This section provides only the information about managedobjects (MOs) related to neighboring UTRAN cells. For more information about how to collect data for the parameters in these MOs, see Mobility Management inConnected Mode Feature Parameter Description.

Collect data for the parameters in the following MOs:

UtranNFreq: used to configure neighboring UTRAN frequencies.

UtranExternalCell: used to configure external UTRAN cells. If PS handover is used, the UtranExternalCell.Rac parameter must be set.

UtranExternalCellPlmn: used to configure additional PLMN IDs for each shared external UTRAN cell. This MO is required only if the NodeB providing theexternal UTRAN cell works in RAN sharing with common carriers mode and multiple operators share the external UTRAN cell.

UtranNCell: used to configure neighbor relationships with UTRAN cells. If a neighboring UTRAN cell supports blind handovers according to the network plan, theblind-handover priority of the cell must be specified by the UtranNCell.BlindHoPriority parameter.

Scenario-specific Data

The following table describes the parameters that must be set in the ENodeBAlgoSwitch MO to set the handover mode and handover algorithm switches forCSFB to UTRAN.

ParameterName

Parameter ID Source Setting Description

HandoverModeswitch

ENodeBAlgoSwitch.HoModeSwitchNetworkplan(negotiationnotrequired)

Set this parameter based on the networkplan.

To activate PS handovers, select the

UtranPsHoSwitch(UtranPsHoSwitch)check box. If this check box is notselected, redirection will be used forCSFB to UTRAN.

To activate blind handovers, select the

BlindHoSwitch(BlindHoSwitch)check box. A blind handover to aninter-RAT cell can be performed only ifa blind-handover priority is specifiedfor the inter-RAT cell. Compared withmeasurement-based handovers, blindhandovers reduce access delays butcause lower handover success rates.

HandoverAlgo switch

ENodeBAlgoSwitch.HoAlgoSwitch Networkplan(negotiationnotrequired)

To activate CSFB to UTRAN, select theUtranCsfbSwitch(UtranCsfbSwitch)check box.

The following table describes the parameters that must be set in the CSFallBackBlindHoCfg MO to set the blind-handover priorities of different RATs for CSFB.

ParameterName


CNOperatorID

CSFallBackBlindHoCfg.CnOperatorId Networkplan(negotiationnotrequired)

Set this parameter based on the networkplan. This parameter specifies the ID of theoperator whose RAT blind-handoverpriorities are to be set.

HighestpriorityInterRat

CSFallBackBlindHoCfg.InterRatHighestPriNetworkplan(negotiationnotrequired)

Set this parameter based on the networkplan. This parameter is set to UTRAN bydefault and specifies the high-priority RAT tobe considered in blind handovers for CSFB.For CSFB to UTRAN, retain the defaultvalue.

SecondpriorityInterRat

CSFallBackBlindHoCfg.InterRatSecondPriNetworkplan(negotiationnotrequired)

Set this parameter based on the networkplan. This parameter is set to GERAN bydefault and specifies the medium-priorityRAT to be considered in blind handovers forCSFB. Ensure that this parameter is set to adifferent value from theCSFallBackBlindHoCfg.InterRatHighestPriandCSFallBackBlindHoCfg.InterRatLowestPriparameters.

LowestpriorityInterRat

CSFallBackBlindHoCfg.InterRatLowestPri Networkplan(negotiationnotrequired)

Set this parameter based on the networkplan. This parameter is set to CDMA2000 bydefault and specifies the low-priority RAT tobe considered in blind handovers for CSFB.Ensure that this parameter is set to adifferent value from theCSFallBackBlindHoCfg.InterRatHighestPriandCSFallBackBlindHoCfg.InterRatSecondPriparameters.

UTRANLCScapability

CSFallBackBlindHoCfg.UtranLcsCap Networkplan(negotiationnotrequired)

Set this parameter based on the networkplan. This parameter specifies the LCScapability of the UTRAN.

7.1.5 Precautions

None

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http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/UtranExternalCell-Rac.html




http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/CSFallBackBlindHoCfg-CnOperatorId.html








http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/CSFallBackBlindHoCfg-UtranLcsCap.html




Configuring a Single eNodeB Using the GUI

Configure a single eNodeB in the general configuration window on the Configuration Management Express (CME) based on the MOs and parameters as describedin section 7.1.4 "Data Preparation."

See the M2000 Help for more information about operations in the general configuration window. Press F1 to launch M2000 Help. Navigate to Introduction to theLTE General Configuration Window and refer to the generic procedure for setting parameters using the CME graphical user interface (GUI).

To find MOs in the planned area, use either of the following methods:

In the Object Group pane, find MOs in the navigation tree. This method applies to users who are familiar with the navigation tree.

In the Search pane, search an MO. This method applies to users who are unfamiliar with the navigation tree.

Configuring eNodeBs in Batches

To configure eNodeBs in batches, perform the following steps:

Step 1 On the GUI, set the parameters listed in Table 7-3, and save the parameter settings as a user-defined template.

The parameters are the same as those described in section 7.1.4 "Data Preparation."

Step 2 Fill in the summary data file with the name of the user-defined template.

The parameter settings in the user-defined template will be applied to the eNodeBs after you import the summary data file into the CME.

----End

For descriptions of the user-defined template and summary data file and also the detailed procedure for configuring eNodeBs in batches, see eNodeB InitialConfiguration Guide.

Table 7-3 Parameters for CSFB to UTRAN

MO Parameter Group Name Parameter

UTRANNFREQ UtranNFreq Local cell identity, Downlink UARFCN

UTRANEXTERNALCELL UtranExternalCell Mobile country code, Mobile network code,UTRAN cell identity, Downlink UARFCN, RNCidentity, Primary scrambling code, Locationarea code

UTRANEXTERNALCELLPLMNUtranExternalCellPlmn UTRAN cell identity, Mobile country code,Mobile network code, Share mobile countrycode, Share mobile network code

UTRANNCELL UtranNCell Local cell identity, Mobile country code,Mobile network code, UTRAN cell identity,Blind handover priority

ENODEBALGOSWITCH ENodeBAlgoSwitch Handover Algo switch, Handover Mode switch

CSFALLBACKBLINDHOCFG CSFallBackBlindHoCfg CN Operator ID, Highest priority InterRat,Second priority InterRat, Lowest priorityInterRat, UTRAN LCS capability

Configuring a Single eNodeB Using MML Commands

The configuration procedure is as follows:

Step 1 Run the following commands to add neighbor relationships with UTRAN cells:

1. ADD UTRANNFREQ

2. ADD UTRANEXTERNALCELL

3. ADD UTRANEXTERNALCELLPLMN

4. ADD UTRANNCELL

For details about parameter settings, see Mobility Management in Connected Mode Feature Parameter Description.

Step 2 Run the MOD ENODEBALGOSWITCH command to set the handover mode and handover algorithm switches for CSFB to UTRAN.

Step 3 Run the MOD CSFALLBACKBLINDHOCFG command to set the blind-handover priorities of different RATs for CSFB.

----End


The CSFB procedure for an LCS request initiated by a UE is the same as the CSFB procedure for a normal mobile-originated call. The CSFB procedure for anLCS request instructed by the MSC towards a UE camping on an E-UTRAN cell is the same as the CSFB procedure for a normal mobile-terminated call.

The following uses the CSFB procedure for a mobile-originated call and that for a mobile-terminated call as an example.

The activation observation procedure is as follows:

Step 1 Enable a UE to camp on an E-UTRAN cell and originate a voice call.

Step 2 Enable the UE to camp on the E-UTRAN cell and receive a voice call.

If the calls continue until they are ended, CSFB to UTRAN takes effect. You can observe the signaling procedures for CSFB to UTRAN.

Figure 7-1 and Figure 7-2 show sample procedures for CSFB to UTRAN for a mobile-originated call and CSFB to UTRAN for a mobile-terminated call, respectively.In the examples, the UE was in idle mode before the call and is forced to fall back to the UTRAN using a redirection.

The same UE is shown in the left and right sides of the figure. This applies to all figures in the rest of this document. The messages on the UMTS side are only for reference.

Figure 7-1 CSFB to UTRAN for a mobile-originated call

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Figure 7-2 CSFB to UTRAN for a mobile-terminated call

If the UE capability is not included in the Initial Context Setup Request (Initial Context Setup Req in the figures) message, the eNodeB initiates a UE capabilitytransfer procedure immediately after receiving this message from the MME. If the UE capability is included in the Initial Context Setup Request message, theeNodeB initiates a UE capability transfer procedure after sending an Initial Context Setup Response (Initial Context Setup Rsp in the figures) message to the MME.

If measurement-based redirection is used for CSFB to UTRAN, the eNodeB delivers the B1-related measurement configuration.



If blind redirection is used for CSFB to UTRAN, the eNodeB does not deliver the B1-related measurement configuration but sends an RRC Connection Release(RRC Conn Rel in the figures) message to the UE. The procedures indicated by dashed lines in Figure 7-1 and Figure 7-2 are optional. As shown in the red andgreen boxes in 0, in the RRC Connection Release message, the cause value is "other" and the target RAT is UTRAN. For an emergency call, the cause value is"CSFBhighpriority."

Figure 7-3 The RRC Connection Release message during CSFB to UTRAN

If PS handover is used for CSFB to UTRAN, the eNodeB initiates a PS handover procedure after receiving a measurement report from the UE, instead of sendingan RRC Connection Release message to the UE. 0 shows the PS handover procedure. As shown in the red and green boxes in Figure 7-5, in the handovercommand sent over the air interface, the cs-FallbackIndicator IE is TRUE and the target RAT is UTRAN.

Figure 7-4 PS handover procedure

Figure 7-5 The MobilityFromEUTRAN message during CSFB to UTRAN

----End

7.1.8 Deactivation

Run the MOD ENODEBALGOSWITCH command with the UtranCsfbSwitch(UtranCsfbSwitch) check box under the ENodeBAlgoSwitch.HoAlgoSwitchparameter cleared.

7.2 Deploying CSFB to GERAN

7.2.1 When to Use CSFB to GERAN

Use LOFD-001034 CS Fallback to GERAN in the initial phase of LTE network deployment when both of the following conditions are met:

The operator owns a mature GERAN network.


For policies on whether to use PS handover or PS redirection for CSFB, see Mobility Management in Connected Mode Feature Parameter Description. If theGERAN cell and E-UTRAN cell cover the same area, or the GERAN cell provides better coverage than the E-UTRAN cell, use CSFB based on blind handover todecrease the CSFB delay.


Collect the operating frequencies, coverage areas, and configurations of the E-UTRAN and GERAN cells. Information about coverage areas includes engineeringparameters of sites (such as latitude and longitude), TX power of cell reference signals (RSs), and neighbor relationship configurations.

Collect the versions and configurations of the NEs in the E-UTRAN, GERAN, and core networks, and ensure that they all support CSFB. Table 7-4 describes therequirements of CSFB to GERAN for the core networks.

Table 7-4 Requirements of CSFB to GERAN for the core networks

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NE Description

MME Supports:







SMS over SGs

MSC Supports:


SMS over SGs



Collect the following information about the UEs supporting GSM and LTE on the live network:


− Whether the UEs support redirection from E-UTRAN to GERAN

− Whether the UEs support PS handover from E-UTRAN to GERAN

− Whether the UEs support GERAN measurements

This information is used to configure neighboring GERAN cells and to determine whether to perform CSFB based on handover or redirection. For details, seeMobility Management in Connected Mode Feature Parameter Description.








Table 7-5 License control item for CSFB to GERAN


LOFD-001034 CS Fallback to GERAN CS Fall Back to GERAN







Generic Data

Before configuring CSFB to GERAN, collect the data related to neighbor relationships with GERAN cells. This section provides only the information about MOsrelated to neighboring GERAN cells. For more information about how to collect data for the parameters in these MOs, see Mobility Management in ConnectedMode Feature Parameter Description.


GeranNfreqGroup: used to configure GERAN carrier frequency groups.

GeranNfreqGroupArfcn: used to configure absolute radio frequency channel numbers (ARFCNs) in each GERAN carrier frequency group.

GeranExternalCell: used to configure external GERAN cells. If PS handover is used, the GeranExternalCell.Rac parameter must be set.

GeranExternalCellPlmn: used to configure additional PLMN IDs for each shared external GERAN cell. This MO is required only if the BTS providing the externalGERAN cell works in RAN sharing with common carriers mode and multiple operators share the external GERAN cell.

GeranNcell: used to configure neighbor relationships with GERAN cells. If a neighboring GERAN cell supports blind handovers according to the network plan,the blind-handover priority of the cell must be specified by the GeranNcell.BlindHoPriority parameter.


The following table describes the parameters that must be set in the ENodeBAlgoSwitch MO to set the handover mode and handover algorithm switches forCSFB to GERAN.

ParameterName

Parameter IDSource Setting Description

Network

Set this parameter based on the networkplan.

To activate PS handovers, select the

GeranPsHoSwitch(GeranPsHoSwitch)check box. To activate CCO, select theGeranCcoSwitch(GeranCcoSwitch)check box. To activate NACC, select theGeranNaccSwitch(GeranNaccSwitch)check box.

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HandoverModeswitch

ENodeBAlgoSwitch.HoModeSwitchplan(negotiationnotrequired)

If none of the preceding check boxes isselected, redirection will be used for CSFBto GERAN.


BlindHoSwitch(BlindHoSwitch) checkbox. A blind handover to an inter-RATcell can be performed only if a blind-handover priority is specified for theinter-RAT cell. Compared withmeasurement-based handovers, blindhandovers reduce access delays butcause lower handover success rates.

HandoverAlgo switch

ENodeBAlgoSwitch.HoAlgoSwitch

Networkplan(negotiationnotrequired)

To activate CSFB to GERAN, select theGeranCsfbSwitch(GeranCsfbSwitch)check box.


ParameterName


CNOperatorID





Set this parameter based on the networkplan. This parameter is set to UTRAN bydefault and specifies the high-priority RAT tobe considered in blind handovers for CSFB.For CSFB to GERAN, set this parameter toGERAN.



Set this parameter based on the networkplan. This parameter is set to GERAN bydefault and specifies the medium-priorityRAT to be considered in blind handovers forCSFB. If theCSFallBackBlindHoCfg.InterRatHighestPriparameter is set to GERAN, this parametercannot be set to GERAN. Ensure that thisparameter is set to a different value from theCSFallBackBlindHoCfg.InterRatHighestPriandCSFallBackBlindHoCfg.InterRatLowestPriparameters.




GERANLCScapability

CSFallBackBlindHoCfg.GeranLcsCap Networkplan(negotiationnotrequired)

Set this parameter based on the networkplan. This parameter specifies the LCScapability of the GERAN.

7.2.5 Precautions

None













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----End


Table 7-6 Parameters for CSFB to GERAN


GERANNFREQGROUP GeranNfreqGroup Local cell identity, BCCH group identity,GERAN version, Starting ARFCN, Bandindicator

GERANNFREQGROUPARFCN GeranNfreqGroupArfcn Local cell identity, BCCH group identity,GERAN ARFCN

GERANEXTERNALCELL GeranExternalCell Mobile country code, Mobile network code,GERAN cell identity, Location area code,Routing area code configure indicator,Band indicator, GERAN ARFCN, Networkcolour code, Base station colour code,DTM indication

GERANEXTERNALCELLPLMN GeranExternalCellPlmn GERAN cell identity, Location area code,Mobile country code, Mobile network code,Share mobile country code, Share mobilenetwork code

GERANNCELL GeranNcell Local cell identity, Mobile country code,Mobile network code, Location area code,GERAN cell identity, Blind handover priority

ENODEBALGOSWITCH ENodeBAlgoSwitch Handover Algo switch, Handover Modeswitch

CSFALLBACKBLINDHOCFG CSFallBackBlindHoCfg CN Operator ID, Highest priority InterRat,Second priority InterRat, Lowest priorityInterRat, GERAN LCS capability


Step 1 Run the following commands to add neighbor relationships with GERAN cells:

1. ADD GERANNFREQGROUP

2. ADD GERANNFREQGROUPARFCN

3. ADD GERANEXTERNALCELL

4. ADD GERANEXTERNALCELLPLMN

5. ADD GERANNCELL


Step 2 Run the MOD ENODEBALGOSWITCH command to set the handover mode and handover algorithm switches for CSFB to GERAN.


----End





If the calls continue until they are ended, CSFB to GERAN takes effect. You can observe the signaling procedures for CSFB to GERAN, which is similar to that forCSFB to UTRAN described in section 7.1.7 "Activation Observation." The only difference is the target RAT.

----End

7.2.8 Deactivation

Run the MOD ENODEBALGOSWITCH command with the GeranCsfbSwitch(GeranCsfbSwitch) check box under the ENodeBAlgoSwitch.HoAlgoSwitchparameter cleared.

7.3 Deploying CSFB to CDMA2000 1xRTT

7.3.1 When to Use CSFB to CDMA2000 1xRTT

Use LOFD-001035 CS Fallback to CDMA2000 1xRTT in the initial phase of LTE network deployment when both of the following conditions are met:

The operator owns a mature CDMA2000 1xRTT network.


For policies on whether to use PS handover or PS redirection for CSFB, see Mobility Management in Connected Mode Feature Parameter Description. If theCDMA2000 1xRTT cell and E-UTRAN cell cover the same area, or the CDMA2000 1xRTT cell provides better coverage than the E-UTRAN cell, use CSFB basedon blind handover to decrease the CSFB delay.


Collect the operating frequencies, coverage areas, and configurations of the E-UTRAN and CDMA2000 1xRTT cells. Information about coverage areas includesengineering parameters of sites (such as latitude and longitude), TX power of cell reference signals (RSs), and neighbor relationship configurations.

Collect the versions and configurations of the NEs in the E-UTRAN, CDMA2000 1xRTT, and core networks, and ensure that they all support CSFB. Table 7-7describes the requirements of CSFB to CDMA2000 1xRTT for the core networks.

Table 7-7 Requirements of CSFB to CDMA2000 1xRTT for the core networks

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MME Supports:

1xCS signaling transfer over the S102 interface, data buffering, and tunnel

reestablishment

Redirection of inter-MME S102 tunnels in the case of MME relocation

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Collect the following information about the UEs supporting CDMA2000 and LTE on the live network:


− Whether the UEs support redirection from E-UTRAN to CDMA2000

− Whether the UEs support PS handover from E-UTRAN to CDMA2000

− Whether the UEs support CDMA2000 measurements

This information is used to configure neighboring CDMA2000 cells and to determine whether to perform CSFB based on handover or redirection. For details, seeMobility Management in Connected Mode Feature Parameter Description.








Table 7-8 License control item for CSFB to CDMA2000 1xRTT


LOFD-001035 CS Fallback to CDMA2000 1xRTT CS Fall Back to CDMA2000 1xRTT(FDD)







Generic Data

Before configuring CSFB to CDMA2000 1xRTT, collect the data related to neighbor relationships with CDMA2000 1xRTT cells. This section provides only theinformation about MOs related to neighboring CDMA2000 1xRTT cells. For more information about how to collect data for the parameters in these MOs, seeMobility Management in Connected Mode Feature Parameter Description.


Cdma2000BandClass: used to configure CDMA2000 band classes

Cdma2000Nfreq: used to configure CDMA2000 frequencies

Cdma2000ExternalCell: used to configure external CDMA2000 cells

Cdma2000ExternalCellPlmn: used to configure additional PLMN IDs for each shared external CDMA2000 cell. This MO is required only if the base stationproviding the external CDMA2000 cell works in RAN sharing with common carriers mode and multiple operators share the external CDMA2000 cell.

Cdma20001XRTTNcell: used to configure neighbor relationships with CDMA2000 1xRTT cells. If a neighboring CDMA2000 1xRTT cell supports blind handoversaccording to the network plan, the blind-handover priority of the cell must be specified by the Cdma20001XRTTNcell.BlindHoPriority parameter.


The following table describes the parameters that must be set in the ENodeBAlgoSwitch MO to set the handover mode and handover algorithm switches forCSFB to CDMA2000 1xRTT.

ParameterName


HandoverModeswitch


Set this parameter based on the network plan.

To activate redirection for CSFB to CDMA2000 1xRTT,

select theCdma1xRttRedirectSwitch(Cdma1xRttRedirectSwitch)check box.


BlindHoSwitch(BlindHoSwitch) check box. A blindhandover to an inter-RAT cell can be performed only if ablind-handover priority is specified for the inter-RAT cell.Compared with measurement-based handovers, blindhandovers reduce access delays but cause lowerhandover success rates.

HandoverAlgo switch


To activate CSFB to CDMA2000 1xRTT, select theCdma1xRttCsfbSwitch(Cdma1xRttCsfbSwitch) checkbox.


ParameterName


CNOperatorID



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Set this parameter based on the networkplan. This parameter is set to UTRAN bydefault and specifies the high-priority RAT tobe considered in blind handovers for CSFB.For CSFB to CDMA2000 1xRTT, set thisparameter to CDMA2000.







CDMA2000LCScapability

CSFallBackBlindHoCfg.CdmaLcsCap Networkplan(negotiationnotrequired)

Set this parameter based on the networkplan. This parameter specifies the LCScapability of the CDMA2000 1xRTT network.

7.3.5 Precautions

None














----End


Table 7-9 Parameters for CSFB to CDMA2000 1xRTT


CDMA2000BANDCLASS Cdma2000BandClass Local cell identity, Band class

CDMA2000NFREQ Cdma2000Nfreq Local cell identity, Band class,Frequency

CDMA2000EXTERNALCELL Cdma2000ExternalCell Sector identity, Band class, Frequency,Physical cell identity, CDMA2000neighbor cell type, Mobile countrycode, Mobile network code

CDMA2000EXTERNALCELLPLMNCdma2000ExternalCellPlmn Sector identity, Share mobile countrycode, Share mobile network code

CDMA20001XRTTNCELL Cdma20001xrttNcell Local cell identity, Sector identity, Blindhandover priority

ENODEBALGOSWITCH ENodeBAlgoSwitch Handover Algo switch, Handover Modeswitch

CSFALLBACKBLINDHOCFG CSFallBackBlindHoCfg CN Operator ID, Highest priorityInterRat, Second priority InterRat,Lowest priority InterRat, CDMA2000LCS capability

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Step 1 Run the following commands to add neighbor relationships with CDMA2000 1xRTT cells:

1. ADD CDMA2000BANDCLASS

2. ADD CDMA2000NFREQ

3. ADD CDMA2000EXTERNALCELL

4. ADD CDMA2000EXTERNALCELLPLMN

5. ADD CDMA20001XRTTNCELL


Step 2 Run the MOD ENODEBALGOSWITCH command to set the handover mode and handover algorithm switches for CSFB to CDMA2000 1xRTT.


----End





If the calls continue until they are ended, CSFB to CDMA2000 1xRTT takes effect. You can observe the signaling procedures for CSFB to CDMA2000 1xRTT,which is the same as that for CSFB to UTRAN described in section 7.1.7 "Activation Observation."

----End

7.3.8 Deactivation

Run the MOD ENODEBALGOSWITCH command with the Cdma1xRttCsfbSwitch(Cdma1xRttCsfbSwitch) check box under theENodeBAlgoSwitch.HoAlgoSwitch parameter cleared.

7.4 Deploying Flash CSFB to UTRAN

7.4.1 When to Use Flash CSFB to UTRAN

When LOFD-001033 CS Fallback to UTRAN has been enabled, use LOFD-001052 Flash CS Fallback to UTRAN if all the following conditions are met:

The E-UTRAN and UTRAN support the RIM with SIB procedure.

UEs comply with 3GPP Release 9.

The core networks support the RIM procedure.

For policies on whether to use PS handover or PS redirection for CSFB, see Mobility Management in Connected Mode Feature Parameter Description. If theUTRAN cell and E-UTRAN cell cover the same area, or the UTRAN cell provides better coverage than the E-UTRAN cell, use CSFB based on blind handover todecrease the CSFB delay.



Collect the versions and configurations of the NEs in the E-UTRAN, UTRAN, and core networks, and ensure that they all support CSFB and the RIM procedure.Table 7-10 describes the requirements of flash CSFB to UTRAN for the core networks.

Table 7-10 Requirements of flash CSFB to UTRAN for the core networks

NE Description

MME Supports:

CSFB

RIM procedures in compliance with 3GPP Release 9

SGSN Supports:

CSFB

RIM procedures in compliance with 3GPP Release 9






− Whether the UEs comply with 3GPP Release 9 specifications





If the core-network equipment is provided by Huawei, the version must be PS8.2 or later.



Operators must purchase and activate the following licenses.

Table 7-11 License control item for flash CSFB to UTRAN

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LOFD-001033 CS Fallback to UTRAN CS Fall Back to UTRAN

LOFD-001052 Flash CS Fallback to UTRAN Flash CS Fallback to UTRAN

If PS handover for CSFB to UTRAN is enabled, CSFB to UTRAN based on PS handover instead of flash CSFB to UTRAN is used for UEs that support PS handovers. For details, see

section 6.4 "LOFD-001052 Flash CS Fallback to UTRAN."

If the UTRAN uses Huawei devices, RIM-based flash CSFB needs to be enabled on the UTRAN.







Generic Data

Before configuring CSFB to UTRAN, collect the data related to neighbor relationships with UTRAN cells. This section provides only the information about MOsrelated to neighboring UTRAN cells and key parameters in these MOs. For more information about how to collect data for the parameters in these MOs, seeMobility Management in Connected Mode Feature Parameter Description.


UtranNFreq: used to configure neighboring UTRAN frequencies.

UtranExternalCell: used to configure external UTRAN cells. If PS handover is used, the UtranExternalCell.Rac parameter must be set.

UtranExternalCellPlmn: used to configure additional PLMN IDs for each shared external UTRAN cell. This MO is required only if the NodeB providing theexternal UTRAN cell works in RAN sharing with common carriers mode and multiple operators share the external UTRAN cell.

UtranNCell: used to configure neighbor relationships with UTRAN cells. If a neighboring UTRAN cell supports blind handovers according to the network plan, theblind-handover priority of the cell must be specified by the UtranNCell.BlindHoPriority parameter.


The following table describes the parameters that must be set in the ENodeBAlgoSwitch MO to set the handover mode and handover algorithm switches for flashCSFB to UTRAN.

ParameterName


HandoverModeswitch



To activate blind handovers, select theBlindHoSwitch(BlindHoSwitch) check box. Ablind handover to an inter-RAT cell can beperformed only if a blind-handover priority isspecified for the inter-RAT cell. Compared withmeasurement-based handovers, blind handoversreduce access delays but cause lower handoversuccess rates.

HandoverAlgo switch


To activate flash CSFB to UTRAN, select theUtranCsfbSwitch(UtranCsfbSwitch) andUtranFlashCsfbSwitch(UtranFlashCsfbSwitch)check boxes.

RIM switch ENodeBAlgoSwitch.RimSwitch Networkplan(negotiationnotrequired)

UTRAN_RIM_SWITCH under this parameterspecifies whether to enable or disable the RIMprocedure that requests event-driven multiplereports from UTRAN cells.

If this switch is turned on, the eNodeB can send

RAN-INFORMATION-REQUEST/Multiple Reportprotocol data units (PDUs) to UTRAN cells torequest event-driven multiple reports.

If this switch is turned off, the eNodeB cannot

send RAN-INFORMATION-REQUEST/MultipleReport PDUs to UTRAN cells.

If this switch is turned off and theUtranFlashCsfbSwitch(UtranFlashCsfbSwitch)check box underENodeBAlgoSwitch.HoAlgoSwitch is selected,the eNodeB sends RAN-INFORMATION-REQUEST/Single Report PDUs to UTRAN cells torequest single reports.

If the UTRAN cells support RAN-INFORMATION-REQUEST/Multiple Report PDUs, it isrecommended that you select theUTRAN_RIM_SWITCH(UTRAN_RIM_SWITCH)check box.

The following table describes the parameters that must be set in the S1Interface MO to set the compliance protocol release of the MME.

ParameterName


MMERelease

S1Interface .MmeReleaseNetwork plan(negotiationnot required)

To active the multiple RIM, set the parameter toRelease_R9(Release 9).

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ParameterName


CNOperatorID





Set this parameter based on the networkplan. This parameter is set to UTRAN bydefault and specifies the high-priority RAT tobe considered in blind handovers for CSFB.For flash CSFB to UTRAN, retain the defaultvalue.







UTRANLCScapability

CSFallBackBlindHoCfg.UtranLcsCap Networkplan(negotiationnotrequired)

Set this parameter based on the networkplan. This parameter specifies the LCScapability of the UTRAN.

7.4.5 Precautions

None














----End


Table 7-12 Parameters for flash CSFB to UTRAN


UTRANNFREQ UtranNFreq Local cell identity, Downlink UARFCN

UTRANEXTERNALCELL UtranExternalCell Mobile country code, Mobile network code,UTRAN cell identity, Downlink UARFCN, RNCidentity, Routing area code configureindicator, Routing area code, Primaryscrambling code, Location area code

UTRANEXTERNALCELLPLMNUtranExternalCellPlmn UTRAN cell identity, Mobile country code,Mobile network code, Share mobile countrycode, Share mobile network code

UTRANNCELL UtranNCell Local cell identity, Mobile country code,

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S1Interface S1Interface MME Release

ENODEBALGOSWITCH ENodeBAlgoSwitch Handover Algo switch, Handover Modeswitch, Redirection switch, RIM switch

CSFALLBACKBLINDHOCFG CSFallBackBlindHoCfg CN Operator ID, Highest priority InterRat,Second priority InterRat, Lowest priorityInterRat, UTRAN LCS capability


Step 1 Run the following commands to add neighbor relationships with UTRAN cells:

1. ADD UTRANNFREQ

2. ADD UTRANEXTERNALCELL

3. ADD UTRANEXTERNALCELLPLMN

4. ADD UTRANNCELL


Step 2 Run the MOD ENODEBALGOSWITCH command to set the handover mode, handover algorithm switches, redirection algorithm switch, and RIM procedureswitch for flash CSFB to UTRAN.

To manually trigger an RIM procedure, run the following commands to turn off and then turn on the RIM procedure switch:

1. MOD ENODEBALGOSWITCH: RimSwitch=UTRAN_RIM_SWITCH-0

2. MOD ENODEBALGOSWITCH: RimSwitch=UTRAN_RIM_SWITCH-1

Step 3 Run the MOD S1INTERFACE command to set the compliance protocol release of the MME.


----End


Enable a UE to camp on an E-UTRAN cell and originate a voice call. If the call continues and the RRC Connection Release message traced on the Uu interfacecarries the information of the neighboring UTRAN cell, flash CSFB to UTRAN has been activated successfully.

The signaling procedure for flash CSFB to UTRAN is similar to that for CSFB to UTRAN described in section 7.1.7 "Activation Observation." The difference is thatthe RRC Connection Release message carries the information of the neighboring UTRAN cell. Check the status of the RIM procedure towards neighboring UTRANcells by running the DSP UTRANRIMINFO command. If the ID of a neighboring UTRAN cell is displayed in the command output, the eNodeB has obtained thesystem information of this neighboring UTRAN cell.

7.4.8 Deactivation

Run the MOD ENODEBALGOSWITCH command with the UtranFlashCsfbSwitch(UtranFlashCsfbSwitch) check box under theENodeBAlgoSwitch.HoAlgoSwitch parameter cleared.

7.5 Deploying Flash CSFB to GERAN

7.5.1 When to Use Flash CSFB to GERAN

When LOFD-001034 CS Fallback to GERAN has been enabled, use LOFD-001053 Flash CS Fallback to GERAN if all the following conditions are met:

The E-UTRAN and GERAN support the RIM with SIB procedure.

UEs comply with 3GPP Release 9.

The core networks support the RIM procedure.

For policies on whether to use PS handover or PS redirection for CSFB, see Mobility Management in Connected Mode Feature Parameter Description. If theGERAN cell and E-UTRAN cell cover the same area, or the GERAN cell provides better coverage than the E-UTRAN cell, use CSFB based on blind handover todecrease the CSFB delay.



Collect the versions and configurations of the NEs in the E-UTRAN, GERAN, and core networks, and ensure that they all support CSFB and the RIM procedure.Table 7-13 describes the requirements of flash CSFB to GERAN for the core networks.

Table 7-13 Requirements of flash CSFB to GERAN for the core networks

NE Description

MME Supports:

CSFB

RIM procedures

SGSN Supports:

CSFB

RIM procedures






− Whether the UEs comply with 3GPP Release 9 specifications

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Table 7-14 License control item for flash CSFB to GERAN


LOFD-001034 CS Fallback to GERAN CS Fall Back to GERAN

LOFD-001053 Flash CS Fallback toGERAN

Flash CS Fallback to GERAN

If PS handover for CSFB to GERAN is enabled, CSFB to GERAN based on PS handover instead of flash CSFB to GERAN is used for UEs that support PS handovers. For details, see

section 6.5 "LOFD-001053 Flash CS Fallback to GERAN."

If the GERAN uses Huawei devices, evolved network assisted cell change (eNACC) between E-UTRAN and GERAN for CSFB needs to be enabled on the GERAN.







Generic Data

Before configuring CSFB to GERAN, collect the data related to neighbor relationships with GERAN cells. This section provides only the information about MOsrelated to neighboring GERAN cells and key parameters in these MOs. For more information about how to collect data for the parameters in these MOs, seeMobility Management in Connected Mode Feature Parameter Description.


GeranNfreqGroup: used to configure GERAN carrier frequency groups.

GeranNfreqGroupArfcn: used to configure ARFCNs in each GERAN carrier frequency group.

GeranExternalCell: used to configure external GERAN cells. If PS handover is used, the GeranExternalCell.Rac parameter must be set.

GeranExternalCellPlmn: used to configure additional PLMN IDs for each shared external GERAN cell. This MO is required only if the BTS providing the externalGERAN cell works in RAN sharing with common carriers mode and multiple operators share the external GERAN cell.

GeranNcell: used to configure neighbor relationships with GERAN cells. If a neighboring GERAN cell supports blind handovers according to the network plan,the blind-handover priority of the cell must be specified by the GeranNcell.BlindHoPriority parameter.


The following table describes the parameters that must be set in the ENodeBAlgoSwitch MO to set the handover mode and handover algorithm switches for flashCSFB to GERAN.

ParameterName


HandoverModeswitch



To activate blind handovers, select theBlindHoSwitch(BlindHoSwitch) check box. Ablind handover to an inter-RAT cell can beperformed only if a blind-handover priority isspecified for the inter-RAT cell. Compared withmeasurement-based handovers, blind handoversreduce access delays but cause lower handoversuccess rates.

HandoverAlgo switch


To activate flash CSFB to GERAN, select theGeranCsfbSwitch(GeranCsfbSwitch) andGeranFlashCsfbSwitch(GeranFlashCsfbSwitch)check boxes.

RIM switch ENodeBAlgoSwitch.RimSwitch Networkplan(negotiationnotrequired)

GERAN_RIM_SWITCH under this parameterspecifies whether to enable or disable the RIMprocedure that requests event-driven multiplereports from GERAN cells.

If this switch is turned on, the eNodeB can send

RAN-INFORMATION-REQUEST/Multiple ReportPDUs to GERAN cells to request event-drivenmultiple reports.

If this switch is turned off, the eNodeB cannot send

RAN-INFORMATION-REQUEST/Multiple ReportPDUs to GERAN cells.

If this switch is turned off and theGeranFlashCsfbSwitch(GeranFlashCsfbSwitch)check box under

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ENodeBAlgoSwitch.HoAlgoSwitch is selected,the eNodeB sends RAN-INFORMATION-REQUEST/Single Report PDUs to GERAN cells torequest single reports.

If the GERAN cells support RAN-INFORMATION-REQUEST/Multiple Report PDUs, it is recommendedthat you select theGERAN_RIM_SWITCH(GERAN_RIM_SWITCH)check box.

The following table describes the parameters that must be set in the S1Interface MO to set the compliance protocol release of the MME.

ParameterName


MMERelease

S1Interface .MmeReleaseNetwork plan(negotiationnot required)

To active the multiple RIM, set the parameter toRelease_R9(Release 9).


ParameterName


CNOperatorID





Set this parameter based on the networkplan. This parameter is set to UTRAN bydefault and specifies the high-priority RAT tobe considered in blind handovers for CSFB.For flash CSFB to GERAN, set thisparameter to GERAN.



Set this parameter based on the networkplan. This parameter is set to GERAN bydefault and specifies the medium-priorityRAT to be considered in blind handovers forCSFB. If theCSFallBackBlindHoCfg.InterRatHighestPriparameter is set to GERAN, this parametercannot be set to GERAN. Ensure that thisparameter is set to a different value from theCSFallBackBlindHoCfg.InterRatHighestPriandCSFallBackBlindHoCfg.InterRatLowestPriparameters.




GERANLCScapability

CSFallBackBlindHoCfg.GeranLcsCap Networkplan(negotiationnotrequired)

Set this parameter based on the networkplan. This parameter specifies the LCScapability of the GERAN.

7.5.5 Precautions

None












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----End


Table 7-15 Parameters for flash CSFB to GERAN


GERANNFREQGROUP GeranNfreqGroup Local cell identity, BCCH group identity,GERAN version, Starting ARFCN, Bandindicator

GERANNFREQGROUPARFCN GeranNfreqGroupArfcn Local cell identity, BCCH group identity,GERAN ARFCN

GERANEXTERNALCELL GeranExternalCell Mobile country code, Mobile network code,GERAN cell identity, Location area code,Routing area code configure indicator,Routing area code, Band indicator, GERANARFCN, Network colour code, Base stationcolour code, DTM indication

GERANEXTERNALCELLPLMN GeranExternalCellPlmn GERAN cell identity, Location area code,Mobile country code, Mobile network code,Share mobile country code, Share mobilenetwork code

GERANNCELL GeranNcell Local cell identity, Mobile country code,Mobile network code, Location area code,GERAN cell identity, Blind handover priority

S1Interface S1Interface MME Release

ENODEBALGOSWITCH ENodeBAlgoSwitch Handover Algo switch, Handover Modeswitch, Redirection switch, RIM switch

CSFALLBACKBLINDHOCFG CSFallBackBlindHoCfg CN Operator ID, Highest priority InterRat,Second priority InterRat, Lowest priorityInterRat, GERAN LCS capability


Step 1 Run the following commands to add neighbor relationships with GERAN cells:

1. ADD GERANNFREQGROUP

2. ADD GERANNFREQGROUPARFCN

3. ADD GERANEXTERNALCELL

4. ADD GERANEXTERNALCELLPLMN

5. ADD GERANNCELL


Step 2 Run the MOD ENODEBALGOSWITCH command to set the handover mode, handover algorithm switches, redirection algorithm switch, and RIM procedureswitch for flash CSFB to GERAN.

Step 3 Run the MOD S1INTERFACE command to set the compliance protocol release of the MME.


----End


Enable a UE to camp on an E-UTRAN cell and originate a voice call. If the call continues and the RRC Connection Release message traced on the Uu interfacecarries the information of the neighboring GERAN cell, flash CSFB to GERAN has been activated successfully.

The signaling procedure for flash CSFB to GERAN is similar to that for CSFB to UTRAN described in section 7.1.7 "Activation Observation." The difference is thatthe RRC Connection Release message carries the information of the neighboring GERAN cell. 0 shows the content of the RRC Connection Release messageduring flash CSFB to GERAN.

Figure 7-6 The RRC Connection Release message during flash CSFB to GERAN






Check the status of the RIM procedure towards neighboring GERAN cells by running the DSP GERANRIMINFO command. If the ID of a neighboring GERAN cell isdisplayed in the command output, the eNodeB has obtained the system information of this neighboring GERAN cell.

7.5.8 Deactivation

Run the MOD ENODEBALGOSWITCH command with the GeranFlashCsfbSwitch(GeranFlashCsfbSwitch) check box under theENodeBAlgoSwitch.HoAlgoSwitch parameter cleared.

7.6 Deploying CSFB with LAI to UTRAN

7.6.1 When to Use CSFB with LAI to UTRAN

Use LOFD-001068 CS Fallback with LAI to UTRAN when both of the following conditions are met:

LOFD-001033 CS Fallback to UTRAN has been enabled.

The E-UTRAN cell has neighboring UTRAN cells that belong to different PLMNs and supports inter-PLMN handovers, or the E-UTRAN cell has neighboringUTRAN cells that have different location area codes (LACs).

Use LOFD-001068 CS Fallback with LAI to UTRAN also when both of the following conditions are met:

LOFD-001033 CS Fallback to UTRAN and LOFD-001034 CS Fallback to GERAN have been enabled.

The neighboring UTRAN and GERAN cells of the E-UTRAN cell have different LAIs.



Collect the versions and configurations of the NEs in the E-UTRAN, UTRAN, and core networks, and ensure that they all support CSFB and the MME supports LAIdelivery. Table 7-16 describes the requirements of CSFB with LAI to UTRAN for the core networks.

Table 7-16 Requirements of CSFB with LAI to UTRAN for the core networks

NE Description

MME Supports:







SMS over SGs

LAI delivery

MSC Supports:


SMS over SGs











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Table 7-17 License control item for CSFB with LAI to UTRAN


LOFD-001068 CS Fallback with LAI to UTRAN CS Fallback with LAI to UTRAN


Data preparation for CSFB with LAI to UTRAN is the same as that for CSFB to UTRAN described in section 7.1.4 "Data Preparation."

7.6.5 Precautions

None


CSFB with LAI to UTRAN is automatically activated when two conditions are met:

The license for this feature has been activated.

CSFB to UTRAN has been activated. For details about how to activate CSFB to UTRAN, see section 7.1.6 "Initial Configuration."



Step 1 Configure two neighboring UTRAN cells with different LAIs for an E-UTRAN cell, and enable the MME to include only one of the two LAIs in the instructionsthat will be delivered to the eNodeB in Step 3 and Step 4.

Step 2 Ensure that the signal strengths of the two UTRAN cells both reach the threshold for event B1.

You can query the threshold by running the LST INTERRATHOUTRANGROUP command.

Step 3 Enable a UE to camp on the E-UTRAN cell and originate a voice call.


If the calls continue until they are ended, CSFB with LAI to UTRAN takes effect. You can observe the signaling procedure for CSFB with LAI to UTRAN, which issimilar to that for CSFB to UTRAN described in section 7.1.7 "Activation Observation." The difference is that the Initial Context Setup Request message carries theLAI that the MME delivers to the eNodeB.

----End

7.6.8 Deactivation

CSFB with LAI to UTRAN is automatically deactivated when its license or CSFB to UTRAN is deactivated. For details about how to deactivate CSFB to UTRAN, seesection 7.1.8 "Deactivation."

7.7 Deploying CSFB with LAI to GERAN

7.7.1 When to Use CSFB with LAI to GERAN

Use LOFD-001069 CS Fallback with LAI to GERAN when both of the following conditions are met:

LOFD-001034 CS Fallback to GERAN has been enabled.

The E-UTRAN cell has neighboring GERAN cells that belong to different PLMNs and supports inter-PLMN handovers, or the E-UTRAN cell has neighboringGERAN cells that have different LACs.

Use LOFD-001069 CS Fallback with LAI to GERAN also when both of the following conditions are met:

LOFD-001033 CS Fallback to UTRAN and LOFD-001034 CS Fallback to GERAN have been enabled.

The neighboring UTRAN and GERAN cells of the E-UTRAN cell have different LAIs.



Collect the versions and configurations of the NEs in the E-UTRAN, GERAN, and core networks, and ensure that they all support CSFB and the MME supportsLAI delivery. Table 7-18 describes the requirements of CSFB with LAI to GERAN for the core networks.

Table 7-18 Requirements of CSFB with LAI to GERAN for the core networks

NE Description

MME Supports:







SMS over SGs

LAI delivery

MSC Supports:


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SMS over SGs













If the core-network equipment is provided by another vendor, check with the vendor whether the equipment supports this feature. This feature can be deployedonly when the core-network equipment supports it.



Table 7-19 License control item for CSFB with LAI to GERAN


LOFD-001069 CS Fallback with LAI toGERAN

CS Fallback with LAI to GERAN


Data preparation for CSFB with LAI to GERAN is the same as that for CSFB to GERAN described in section 7.2.4 "Data Preparation."

7.7.5 Precautions

None


This feature is automatically activated when two conditions are met:

The license for this feature has been activated.

CSFB to GERAN has been activated. For details about how to activate CSFB to GERAN, see section 7.2.6 "Initial Configuration."



Step 1 Configure two neighboring GERAN cells with different LAIs for an E-UTRAN cell, and enable the MME to include only one of the two LAIs in the instructionsthat will be delivered to the eNodeB in Step 3 and Step 4.

Step 2 Ensure that the signal strengths of the two GERAN cells both reach the threshold for event B1.

You can query the threshold by running the LST INTERRATHOGERANGROUP command.

Step 3 Enable a UE to camp on the E-UTRAN cell and originate a voice call.


If the calls continue until they are ended, CSFB with LAI to GERAN takes effect. You can observe the signaling procedure for CSFB with LAI to GERAN, which issimilar to that for CSFB to UTRAN described in section 7.1.7 "Activation Observation." The difference is that the Initial Context Setup Request message carries theLAI that the MME delivers to the eNodeB.

----End

7.7.8 Deactivation

CSFB with LAI to GERAN is automatically deactivated when its license or CSFB to GERAN is deactivated. For details about how to deactivate CSFB to GERAN, seesection 7.2.8 "Deactivation."

7.8 Deploying E-UTRAN to UTRAN CS/PS Steering

7.8.1 When to Use E-UTRAN to UTRAN CS/PS Steering

Use LOFD-001078 E-UTRAN to UTRAN CS/PS Steering when all of the following conditions are met:

LOFD-001034 CS Fallback to UTRAN and LOFD-001019 PS Inter-RAT Mobility between E-UTRAN and UTRAN have been activated.

The operator owns multiple UTRAN frequencies.

The operator wants to divert CS or PS services to specific UTRAN frequencies based on the network plan and loads.


Determine whether LOFD-001034 CS Fallback to UTRAN and LOFD-001019 PS Inter-RAT Mobility between E-UTRAN and UTRAN have been activated.

Collect the following information about UEs that support UMTS and LTE on the live network:Supported frequency bands


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Collect the operating frequencies and frequency policies of the E-UTRAN and UTRAN. It is recommended that the frequency policies for UTRAN and E-UTRAN bethe same. For example, if F1 is the preferred frequency for voice services on UTRAN, the same configuration is recommended for E-UTRAN.

Collect the configurations and versions of E-UTRAN and UTRAN equipment to check whether CSFB is supported.



For E-UTRAN to UTRAN CS/PS Steering, the eNodeB must collaborate with the core-network equipment which supports CS Fallback to UTRAN.


If the core-network equipment is provided by another vendor, ask the vendor whether the equipment supports CS Fallback to UTRAN.



Table 7-20 License control item for E-UTRAN to UTRAN CS/PS Steering


LOFD-001078 E-UTRAN to UTRAN CS/PS Steering E-UTRAN to UTRAN CS/PS Steering







Generic Data

Generic data preparation for LOFD-001078 E-UTRAN to UTRAN CS/PS Steering is the same as for LOFD-001033 CS Fallback to UTRAN. For details, see section7.1.4 "Data Preparation."


The following table describes the parameter that must be set in the ENodeBAlgoSwitch MO to enable E-UTRAN to UTRAN CS/PS Steering.

ParameterName


FrequencyLayerSwitch

ENodeBAlgoSwitch.FreqLayerSwtichNetworkplan(negotiationnotrequired)

When CSFB to UTRAN and PS inter-RAT mobility between E-UTRAN and UTRAN have been configured, set this parameteras follows:

Select the

UtranFreqLayerMeasSwitch(UtranFreqLayerMeasSwitch)check box to enable measurement-based handover for E-UTRAN to UTRAN CS/PS Steering.

Select the

UtranFreqLayerBlindSwitch(UtranFreqLayerBlindSwitch)check box to enable blind handover for E-UTRAN to UTRANCS/PS Steering.

The two check boxes can be simultaneously selected.

The following table describes the parameter that must be set in a UtranNFreq MO to set the CS service priority for a UTRAN frequency.

ParameterName


CS servicepriority

UtranNFreq.CsPriority Network plan(negotiationnot required)

Set this parameter based on the networkplan. This parameter specifies the CSservice priority for the UTRAN frequency.

7.8.5 Precautions

None









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----End


Table 7-21 Parameters for E-UTRAN to UTRAN CS/PS Steering


ENodeBAlgoSwitch User-defined sheet. EnodeBAlgoSwitch isrecommended.

FreqLayerSwtich

UTRANNFREQ User-defined sheet. UTRANNFREQ isrecommended.

CsPriority


Step 1 Run the MOD ENODEBALGOSWITCH command with UtranFreqLayerMeasSwitch(UtranFreqLayerMeasSwitch),UtranFreqLayerBlindSwitch(UtranFreqLayerBlindSwitch), or both selected under the Frequency Layer Switch parameter.

Step 2 Run the MOD UTRANNFREQ command to set CS service priorities for UTRAN frequencies.

----End



Step 1 Verify that the UE supports CSFB and multiple UTRAN frequencies are available.

Step 2 Enable measurement-based and blind handover for E-UTRAN to UTRAN CS/PS Steering. Set a high PS service priority for UTRAN frequency F1 and ahigh CS service priority for UTRAN frequency F2.

Step 3 Have the UE camp on an LTE cell and initiate a voice call in the cell.

The expected result is that the UE falls back to the UTRAN cell operating on F2.

Step 4 Have the UE camp on the LTE cell and initiate PS services. Move the UE to the LTE cell edge.

The expected result is that the UE is handed over to the UTRAN cell operating on F1.

----End

7.8.8 Deactivation

Run the MOD ENODEBALGOSWITCH command with the check boxes under the Frequency Layer Switch parameter cleared.

7.9 Performance Optimization

End-to-end CSFB delay includes the processing time at the LTE side and that at the GSM or UMTS side. Processing at any side may affect the end-to-end delayand user experience.

For details about processing in Huawei GSM equipment, see Interoperability Between GSM and LTE Feature Parameter Description.

For details about processing in Huawei UMTS equipment, see Interoperability Between UMTS and LTE Feature Parameter Description.

7.9.1 Monitoring

CSFB allows UEs under LTE coverage to shift to CS networks when CS services arrive. Use the L.CSFB.PrepAtt and L.CSFB.PrepSucc counters to monitor CSFBperformance. Use the L.CSFB.E2W and L.CSFB.E2G counters (corresponding to UMTS and GSM, respectively) to distinguish between the target CS networks.

Use the L.RRCRedirection.E2W, L.RRCRedirection.E2G, L.IRATHO.E2W.PrepAttOut, and L.IRATHO.E2G.PrepAttOut counters to monitor the CSFB mechanismsincluding redirections and handovers.

The L.RRCRedirection.E2W and L.RRCRedirection.E2G counters measure all redirections including those caused by factors other than CSFB. The L.IRATHO.E2W.PrepAttOut andL.IRATHO.E2G.PrepAttOut counters measure all handovers including those caused by factors other than CSFB.

CSFB is an end-to-end service. The performance counters on the LTE side only indicate the success rate of the CSFB procedure on the LTE side. Therefore, the performance counters onthe LTE side cannot directly show the user experience of the CSFB procedure. It is recommended that you perform drive tests and use the performance counters on the UE side to indicatethe actual user experience of the CSFB procedure.

7.9.2 Parameter Optimization

Blind Handovers for CSFB

Compared with measurement-based handovers, blind handovers reduce access delays but cause lower handover success rates.

Set blind-handover priorities of different RATs according to the operator's policy. When the handover success rate or service setup success rate is low due to poorUTRAN or GERAN coverage, adjust the blind-handover priorities for different RATs or deactivate blind handovers to improve CSFB performance.

The following table describes the parameters in the CSFallBackBlindHoCfg MO used to set the blind-handover priorities of different RATs for CSFB.

ParameterName


CNOperatorID



Highest CSFallBackBlindHoCfg.InterRatHighestPriNetwork Set this parameter based on the network








priorityInterRat

plan(negotiationnotrequired)

plan. This parameter is set to UTRAN bydefault and specifies the high-priority RAT tobe considered in blind handovers for CSFB.







The following table describes the parameter in the ENodeBAlgoSwitch MO used to activate or deactivate blind handovers.

ParameterName


HandoverModeswitch

ENodeBAlgoSwitch.HoModeSwitchNetwork plan(negotiationnotrequired)

To activate blind handovers, select theBlindHoSwitch(BlindHoSwitch)check box. A blind handover to aninter-RAT cell can be performed only ifa blind-handover priority is specifiedfor the inter-RAT cell. Compared withmeasurement-based handovers, blindhandovers reduce access delays butcause lower handover success rates.

To deactivate blind handovers, clearthe BlindHoSwitch(BlindHoSwitch)check box.

Measurement-based Handovers for CSFB

An appropriate event B1 threshold for CSFB ensures that inter-RAT handovers are triggered in a timely fashion. A high threshold results in a low probability oftriggering event B1, thereby affecting user experience. A low threshold results in a high probability of triggering event B1, but causes a high probability of incorrecthandover decisions and a low handover success rate. Tune the threshold based on site conditions.

Event B1 for CSFB has a time-to-trigger parameter. This parameter lowers the probability of incorrect handover decisions and raises the handover success rate.However, if the value of this parameter is too large, CSFB delay is extended, affecting user experience. Tune this parameter based on site conditions.

Appropriate settings of the threshold and time-to-trigger for event B1 raise the handover success rate and lower the call drop rate. The related parameters are asfollows:

CSFB to UTRAN: CSFallBackHo.CsfbHoUtranB1ThdRscp, CSFallBackHo.CsfbHoUtranB1ThdEcn0, and CSFallBackHo.CsfbHoUtranTimeToTrig

CSFB to GERAN: CSFallBackHo.CsfbHoGeranB1Thd and CSFallBackHo.CsfbHoGeranTimeToTrig

CSFB to CDMA2000 1xRTT: CSFallBackHo.CsfbHoCdmaB1ThdPs and CSFallBackHo.CsfbHoCdmaTimeToTrig

These parameters belong to the CSFallBackHo MO and are described in the following table.

ParameterName


Local cellID

CSFallBackHo.LocalCellId Network plan(negotiationnot required)

Set this parameter based on thenetwork plan.

CSFBUtranEventB1Time ToTrig

CSFallBackHo.CsfbHoUtranTimeToTrig Network plan(negotiationnot required)

Set this parameter based on thenetwork plan. This parameterspecifies the time-to-trigger forevent B1 in CSFB to UTRAN.When CSFB to UTRAN isrequired, this parameter must beset, because it is used by UEs asone of the conditions fortriggering event B1.

When a UE detects that thesignal quality in at least oneUTRAN cell meets the enteringcondition, it does not immediatelysend a measurement report tothe eNodeB. Instead, the UEsends a measurement report onlywhen the signal quality has beenmeeting the entering conditionthroughout a period defined bythis parameter.

An appropriate value for thisparameter reduces theprobability of random events B1and the average number ofhandovers, thereby eliminating

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unnecessary handovers.

CSFBUTRANEventB1RSCPTriggerThreshold

CSFallBackHo.CsfbHoUtranB1ThdRscp Network plan(negotiationnot required)

Set this parameter based on thenetwork plan. This parameterspecifies the RSCP threshold forevent B1 in CSFB to UTRAN.When CSFB to UTRAN isrequired, this parameter must beset, because it is used by UEs asone of the conditions fortriggering event B1. Event B1 istriggered when the RSCPmeasured by the UE is higherthan the value of this parameterand all other conditions are alsomet.

CSFBUTRANEventB1ECN0TriggerThreshold

CSFallBackHo.CsfbHoUtranB1ThdEcn0 Network plan(negotiationnot required)

This parameter specifies theEc/No threshold for event B1 inCSFB to UTRAN. When CSFB toUTRAN is required, thisparameter must be set, becauseit is used by UEs as one of theconditions for triggering eventB1. Event B1 is triggered whenthe Ec/No measured by the UE ishigher than the value of thisparameter and all otherconditions are also met.

Set this parameter to a largevalue for a cell with a large signalfading variance in order toreduce the probability ofunnecessary handovers.

Set this parameter to a smallvalue for a cell with a small signalfading variance in order toensure timely handovers.

CSFBGERANEventB1TriggerThreshold

CSFallBackHo.CsfbHoGeranB1Thd Network plan(negotiationnot required)

Set this parameter based on thenetwork plan. This parameterspecifies the RSSI threshold forevent B1 in CSFB to GERAN.Event B1 is triggered when themeasured RSSI of a GERAN cellreaches the value of thisparameter and all otherconditions are also met.

CSFBGeranEventB1Time ToTrig

CSFallBackHo.CsfbHoGeranTimeToTrigNetwork plan(negotiationnot required)

Set this parameter based on thenetwork plan. This parameterspecifies the time-to-trigger forevent B1 in CSFB to GERAN.When CSFB to GERAN isrequired, this parameter must beset, because it is used by UEs asone of the conditions fortriggering event B1.

When a UE detects that thesignal quality in at least oneGERAN cell meets the enteringcondition, it does not immediatelysend a measurement report tothe eNodeB. Instead, the UEsends a measurement report onlywhen the signal quality has beenmeeting the entering conditionthroughout a period defined bythis parameter.

An appropriate value for thisparameter reduces theprobability of random events B1and the average number ofhandovers, thereby eliminatingunnecessary handovers.

CSFBCDMA2000EventB1TriggerThreshold

CSFallBackHo.CsfbHoCdmaB1ThdPs Network plan(negotiationnot required)

Set this parameter based on thenetwork plan. This parameterspecifies the pilot strengththreshold for event B1 in CSFB toCDMA2000 1xRTT. Event B1 istriggered when the measuredpilot strength of a CDMA20001xRTT cell reaches the value ofthis parameter and all otherconditions are also met.

CSFBCDMAEventB1Time ToTrig

CSFallBackHo.CsfbHoCdmaTimeToTrig Network plan(negotiationnot required)

Set this parameter based on thenetwork plan. This parameterspecifies the time-to-trigger forevent B1 in CSFB to CDMA20001xRTT. When CSFB toCDMA2000 is required, thisparameter must be set, becauseit is used by UEs as one of theconditions for triggering eventB1.









When a UE detects that thesignal quality in at least oneCDMA2000 1xRTT cell meets theentering condition, it does notimmediately send a measurementreport to the eNodeB. Instead,the UE sends a measurementreport only when the signalquality has been meeting theentering condition throughout aperiod defined by this parameter.

An appropriate value for thisparameter reduces theprobability of random events B1and the average number ofhandovers, thereby eliminatingunnecessary handovers.

7.9.3 EBC Description

Table 7-22 describes the event-based counters (EBCs) for CSFB.

Table 7-22 EBCs for CSFB

Event Name Counter Name CounterDescription

Value

PRIVATE_RRC_CON_REL ucRedirectionTriggerIndicator forRedirection Trigger

0: CSFB

1: others

ucCSFBHighPriority Emergency CallIndicator

0: indicates a non-emergency-

call.

1: indicates an emergency call.

ucSIBInfo Indicator forIncluding TargetCell SIB in RRCConnection ReleaseMessage

0: indicates that the SIB

information of the target cell isnot included in the RRCConnection Release message.

1: indicates that the SIB

information of the target cell isincluded in the RRCConnection Release message.

ucTargetType Target Cell RAT 0: indicates that the target cell

is an E-UTRAN cell.

1: indicates that the target cell

is a UTRAN cell.

2: indicates that the target cell

is a GERAN cell.

PRIVATE_INTER_RAT_HOucHoType Handover Type:Intra-Frequency/Inter-Frequency/Inter-RAT

1: indicates an intra-frequency

handover.

2: indicates an inter-frequency

handover.

3: indicates a handover to

UTRAN.

4: indicates a handover to TD-

SCDMA.


CDMA2000.


GERAN.

ucHoTrigger Handover Trigger 0: indicates a reserved value.

1: indicates a distance-based

handover.

2: indicates a coverage-based

handover.

3: indicates a load-based

handover.

ucChoice Cause Category 0: indicates that the procedure

is complete.

1: indicates that the procedure

fails due to radio-network-layerfaults.


fails due to transport-layerfaults.


fails due to NAS faults.


fails due to protocol-layerfaults.


fails due to other faults.

ucCauseValue Cause Value 23: S1_CS_FALLBACK

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ucCSFBHighPriority Indicator forEmergency Call-Triggered CSFB

0: indicates a non-emergency-

call.

1: indicates an emergency call.

7.10 Troubleshooting

7.10.1 Fault 1

Fault Description

A UE reselects an inter-RAT neighboring cell directly after initiating a voice call in an E-UTRAN cell, and the S1 interface tracing result shows that CSFB is nottriggered.

Fault Handling

Step 1 Create an S1 interface tracing task, use the UE to camp on the E-UTRAN cell again, and check whether the value of the information element (IE) ePS-attach-type-value is "combined-attach" in the traced Attach Request message. If so, go to Step 2. If not, replace the UE with one that supports combinedEPS/IMSI attach, and try again.

Step 2 Check whether the traced Attach Accept message includes the IE cs-domain-not-available. If it does, go to Step 3. If not, contact Huawei technical support.

Step 3 Contact the vendors of core network NEs to ensure the following:

Attach procedures to the CS domain are allowed according to the subscription data on the HSS.

The core network supports CSFB.

The SGs interface is correctly configured.

----End

7.10.2 Fault 2

Fault Description

An eNodeB delivers an RRC Connection Reconfiguration message to a UE that has initiated a voice call in the LTE network, but the eNodeB does not receive ameasurement report.

Fault Handling

Step 1 Check whether the RRC Connection Reconfiguration message contains B1-related measurement configurations and whether the information about theinter-RAT systems in the configuration is correct. If it is, go to Step 2. If not, rectify the faults and try again.

Step 2 Check whether the coverage of the inter-RAT neighboring cell is good enough. If the coverage is not good enough, adjust B1-related parameters or useCSFB based on blind handovers.

For details about how to adjust B1-related parameters, see Mobility Management in Connected Mode Feature Parameter Description.

----End

7.10.3 Fault 3

Fault Description

Even when blind handovers are configured as the preferred choice in the operator's policy, instead of triggering a blind handover for CSFB, an eNodeB delivers aninter-RAT measurement configuration to a UE that has initiated a voice call.

Fault Handling

Step 1 Run the LST ENODEBALGOSWITCH command and check the setting of BlindHoSwitch under the Handover Mode switch parameter. IfBlindHoSwitch is Off, run the MOD ENODEBALGOSWITCH command with the BlindHoSwitch(BlindHoSwitch) check box under theENodeBAlgoSwitch.HoModeSwitch parameter selected. In addition, check the CSFB mechanism and perform the following:

If CSFB to UTRAN is required, go to Step 2.

If CSFB to GERAN is required, go to Step 3.

If CSFB to CDMA2000 1xRTT is required, go to Step 4.

Step 2 Run the LST UTRANNCELL command and check whether Blind handover priority is 0 for a neighboring UTRAN cell that is supposed to accept incomingblind handovers.

If Blind handover priority is 0, blind handovers to this cell are not allowed. In this case, run the MOD UTRANNCELL command with the Blindhandover priority parameter set to a value other than 0.

If Blind handover priority is not 0, contact Huawei technical support.

Step 3 Run the LST GERANNCELL command and check whether Blind handover priority is 0 for a neighboring GERAN cell that is supposed to accept incomingblind handovers.

If Blind handover priority is 0, blind handovers to this cell are not allowed. In this case, run the MOD GERANNCELL command with the Blindhandover priority parameter set to a value other than 0.


Step 4 Run the LST CDMA20001XRTTNCELL command to check whether Blind handover priority is 0 for a neighboring CDMA2000 1xRTT cell that issupposed to accept incoming blind handovers.

If Blind handover priority is 0, blind handovers to this cell are not allowed. In this case, run the MOD CDMA20001XRTTNCELL command with the Blindhandover priority parameter set to a value other than 0.


----End

7.10.4 CS Fallback with LAI to UTRAN

Table 7-23 shows the alarms related to the feature.

Table 7-23 Alarm list

Alarm ID Alarm Name Network Element Feature ID Feature Name

29221 LTE-WCDMA Inter-System eNodeB LOFD-001068 CS Fallback with LAI

l

l

l

l

l

l

l

l

l

l

l

l

l

l











Outgoing Cell Handover SuccessRate Too Low

to UTRAN

7.10.5 CS Fallback with LAI to GERAN

Table 7-24 shows the alarms related to the feature.

Table 7-24 Alarm list

Alarm ID Alarm Name Network Element Feature ID Feature Name

29222 LTE-GERAN Inter-SystemOutgoing Cell Handover SuccessRate Too Low

eNodeB LOFD-001069 CS Fallback with LAIto GERAN

8 Parameters

Table 8-1 Parameter description

MO Parameter ID MML Command FeatureID

FeatureName

Description

Cdma20001XRTTNcellBlindHoPriority ADDCDMA20001XRTTNCELL

MODCDMA20001XRTTNCELL

LSTCDMA20001XRTTNCELL

LOFD-002001 /TDLOFD-002001

LBFD-002018 /TDLBFD-002018

AutomaticNeighbourRelation(ANR)

MobilityManagement

Meaning:Indicates the priority of the neighboring cell during blindhandovers. Blind handover is a process in which the eNodeBinstructs a UE to hand over to a specified neighboring cell withoutmeasurements. There are 32 priorities altogether. The priority has apositive correlation with the value of this parameter. Note that thevalue 0 indicates that blind handovers to the neighboring cell areprohibited.

GUI Value Range:0~32

Unit:None

Actual Value Range:0~32

Default Value:0

UtranNCell BlindHoPriority ADD UTRANNCELL

MOD UTRANNCELL

LST UTRANNCELL

LBFD-002018 /TDLBFD-002018

MobilityManagement

Meaning:Indicates the priority of the neighboring cell during blindhandovers. Blind handover is a process in which the eNodeBinstructs a UE to hand over to a specified neighboring cell. There 32 priorities altogether. The priority has a positive correlation with value of this parameter. Note that the value 0 indicates that blindhandovers to the neighboring cell are not allowed.


Unit:None


Default Value:0

GeranNcell BlindHoPriority ADD GERANNCELL

MOD GERANNCELL

LST GERANNCELL

LBFD-002018 /TDLBFD-002018

LOFD-001020 /TDLOFD-001020

LOFD-001045 /TDLOFD-001045

LOFD-001046 /TDLOFD-001046

LOFD-001073 /TDLOFD-001073

MobilityManagement

PS Inter-RATMobilitybetween E-UTRAN andGERAN

Inter-RATLoad Sharingto GERAN

Service basedinter-RAThandover toGERAN

Distancebased inter-RAThandover toGERAN

Meaning:Indicates the priority of the neighboring cell during blindhandovers. Blind handover is a process in which the eNodeBinstructs a UE to hand over to a specified neighboring cell. There 32 priorities altogether. The priority has a positive correlation with value of this parameter. Note that the value 0 indicates that blindhandovers to the neighboring cell are not allowed.


Unit:None


Default Value:0

CSFallBackBlindHoCfgCdmaLcsCap MODCSFALLBACKBLINDHOCFG

LSTCSFALLBACKBLINDHOCFG

LOFD-001035

LOFD-001047 /TDLOFD-001047

CS Fallbackto CDMA20001xRTT

LoCationServices(LCS)

Meaning:Indicates the Location Services (LCS) capability of theCDMA2000. If this parameter is set to ON, the CDMA2000 supportsLCS. If this parameter is set to OFF, the CDMA20000 does notsupport LCS.

GUI Value Range:OFF(Off), ON(On)

Unit:None

Actual Value Range:OFF, ON

Default Value:OFF(Off)

CSFallBackBlindHoCfgCnOperatorId LSTCSFALLBACKBLINDHOCFG

MODCSFALLBACKBLINDHOCFG

None None Meaning:Indicates the index of the operator.

GUI Value Range:0~5

Unit:None



http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/add_cdma20001xrttncell.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/mod_cdma20001xrttncell.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/lst_cdma20001xrttncell.html


http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/add_utranncell.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/mod_utranncell.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/lst_utranncell.html


http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/add_geranncell.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/mod_geranncell.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/lst_geranncell.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/CSFallBackBlindHoCfg-CdmaLcsCap.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/mod_csfallbackblindhocfg.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/lst_csfallbackblindhocfg.html







Default Value:None

CSFallBackHo CsfbHoCdmaB1ThdPs MOD CSFALLBACKHO

LST CSFALLBACKHO

LOFD-001035


Meaning:Indicates the pilot strength threshold related to event B1,which is used in CS fallback to CDMA2000. A UE sends ameasurement report related to event B1 to the eNodeB when the pilotstrength in at least one CDMA2000 cell exceeds this threshold andother triggering conditions are met. For details, see 3GPP TS 36.331.

GUI Value Range:-63~0

Unit:0.5dB

Actual Value Range:-31.5~0, step:0.5

Default Value:-34

CSFallBackHo CsfbHoCdmaTimeToTrig MOD CSFALLBACKHO

LST CSFALLBACKHO

LOFD-001035


Meaning:Indicates the time-to-trigger for event B1, which is used inCS fallback to CDMA2000. When CS fallback to CDMA2000 isapplicable, this parameter is set for UEs and used in the evaluation ofwhether to trigger event B1. When detecting that the signal quality inat least one CDMA2000 cell meets the entering condition, the UEdoes not send a measurement report to the eNodeB immediately.Instead, the UE sends a report only when the signal qualitycontinuously meets the entering condition during the time-to-trigger.This parameter helps reduce the number of occasionally triggeredevent reports, the average number of handovers, and the number ofwrong handovers, and hence helps prevent unnecessary handovers.For details, see 3GPP TS 36.331.

GUI Value Range:0ms, 40ms, 64ms, 80ms, 100ms, 128ms, 160ms,256ms, 320ms, 480ms, 512ms, 640ms, 1024ms, 1280ms, 2560ms,5120ms

Unit:ms

Actual Value Range:0ms, 40ms, 64ms, 80ms, 100ms, 128ms, 160ms,256ms, 320ms, 480ms, 512ms, 640ms, 1024ms, 1280ms, 2560ms,5120ms

Default Value:40ms

CSFallBackHo CsfbHoGeranB1Thd MOD CSFALLBACKHO

LST CSFALLBACKHO

LOFD-001034 /TDLOFD-001034

CS Fall Backto GERAN

Meaning:Indicates the RSSI threshold for event B1 that is used in CSfallback to GERAN. A UE sends a measurement report related toevent B1 to the eNodeB when the RSSI in at least one GERAN exceeds this threshold and other triggering conditions are met. Fordetails, see 3GPP TS 36.331.

GUI Value Range:-110~-48

Unit:dBm

Actual Value Range:-110~-48

Default Value:-103

CSFallBackHo CsfbHoGeranTimeToTrigMOD CSFALLBACKHO

LST CSFALLBACKHO

LOFD-001034 /TDLOFD-001034

CS Fall Backto GERAN

Meaning:Indicates the time-to-trigger for event B1 that is used in CSfallback to GERAN. When CS fallback to GERAN is applicable, thisparameter is set for UEs and used in the evaluation of whether totrigger event B1. When detecting that the signal quality in at leastone GERAN cell meets the entering condition, the UE does not senda measurement report to the eNodeB immediately. Instead, the UEsends a report only when the signal quality continuously meets theentering condition during the time-to-trigger. This parameter helpsdecrease the number of occasionally triggered event reports, theaverage number of handovers, and the number of wrong handovers,and thus helps prevent unnecessary handovers. For details, see3GPP TS 36.331.


Unit:ms


Default Value:40ms

CSFallBackHo CsfbHoUtranB1ThdEcn0 MOD CSFALLBACKHO

LST CSFALLBACKHO

LOFD-001033 /TDLOFD-001033

CS Fallbackto UTRAN

Meaning:Indicates the Ec/No threshold for event B1, which is used inCS fallback to UTRAN. When CS fallback to UTRAN is required, thisparameter is set for UEs and used in the evaluation about whether totrigger event B1. This parameter indicates the Ec/No requirement the UTRAN cells to be included in the measurement report. A UEsends a measurement report related to event B1 to the eNodeB whenthe Ec/No in at least one UTRAN cell exceeds this threshold andother triggering conditions are met. For a cell with large signal fadingvariance, set this parameter to a large value to prevent unnecessaryhandovers. For a cell with small signal fading variance, set thisparameter to a small value to ensure timely handovers. For details,see 3GPP TS 36.331.

GUI Value Range:-48~0

Unit:0.5dB

Actual Value Range:-24~0, step:0.5

Default Value:-13


http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/mod_csfallbackho.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/lst_csfallbackho.html















CSFallBackHo CsfbHoUtranB1ThdRscp MOD CSFALLBACKHO

LST CSFALLBACKHO

LOFD-001033 /TDLOFD-001033

CS Fallbackto UTRAN

Meaning:Indicates the RSCP threshold for event B1, which is used inCS fallback to UTRAN. When CS fallback to UTRAN is applicable, thisparameter is set for UEs and used in the evaluation about whether totrigger event B1. This parameter indicates the RSCP requirement the UTRAN cells to be included in the measurement report. A UEsends a measurement report related to event B1 to the eNodeB whenthe RSCP in at least one UTRAN cell exceeds this threshold andother triggering conditions are met. For details, see 3GPP TS 36.331.

GUI Value Range:-120~-25

Unit:dBm

Actual Value Range:-120~-25

Default Value:-106

CSFallBackHo CsfbHoUtranTimeToTrig MOD CSFALLBACKHO

LST CSFALLBACKHO

LOFD-001033 /TDLOFD-001033

CS Fallbackto UTRAN

Meaning:Indicates the time-to-trigger for event B1 that is used in CSfallback to UTRAN. When CS fallback to UTRAN is applicable, thisparameter is set for UEs and used in the evaluation of whether totrigger event B1. When detecting that the signal quality in at leastone UTRAN cell meets the entering condition, the UE does not send ameasurement report to the eNodeB immediately. Instead, the UEsends a report only when the signal quality continuously meets theentering condition during the time-to-trigger. This parameter helpsdecrease the number of occasionally triggered event reports, theaverage number of handovers, and the number of wrong handovers,and thus helps prevent unnecessary handovers. For details, see3GPP TS 36.331.


Unit:ms


Default Value:40ms

UtranNFreq CsPriority ADD UTRANNFREQ

MOD UTRANNFREQ

LST UTRANNFREQ

LOFD-001033 /TDLOFD-001033

LOFD-001078 /TDLBFD-001078

CS Fallbackto UTRAN

E-UTRAN toUTRAN CS/PSSteering

Meaning:Indicates the circuit switched (CS) priority of the neighboringUTRAN frequency, that is, the priority for the neighboring UTRANfrequency to carry CS services. It is used in CSFB-triggeredhandovers.

When UtranFreqLayerMeasSwitch is turned on: If there are both highand low CS-priority UTRAN frequencies, the high CS-priority UTRANfrequencies are preferentially measured; if there are only low CS-priority UTRAN frequencies, these low CS-priority UTRAN frequenciesare measured.

If UtranFreqLayerBlindSwitch is turned on, the target cell for a blindhandover is preferentially selected from the neighboring UTRAN cellson high CS-priority frequencies. If all neighboring UTRAN cells are onlow CS-priority frequencies, the target cell is selected from allneighboring UTRAN cells.

GUI Value Range:LOW_PRIORITY(Low Priority),HIGH_PRIORITY(High Priority)

Unit:None

Actual Value Range:LOW_PRIORITY, HIGH_PRIORITY

Default Value:HIGH_PRIORITY(High Priority)

ENodeBAlgoSwitch FreqLayerSwtich MODENODEBALGOSWITCH

LST ENODEBALGOSWITCH

LOFD-001078 /TDLOFD-001078

E-UTRAN toUTRAN CS/PSSteering

Meaning:Indicates the switch used to enable or disable the UTRANhierarchy-based measurement algorithm and the UTRAN hierarchy-based blind-handover algorithm.If UtranFreqLayerMeasSwitch isturned on, the UTRAN hierarchy-based measurement algorithm takeseffect for measurements related to coverage-based and CSFB-triggered handovers from the E-UTRAN to the UTRAN.

If UtranFreqLayerBlindSwitch is turned on, the UTRAN hierarchy-based blind-handover algorithm takes effect for coverage-based andCSFB-triggered handovers from the E-UTRAN to the UTRAN.

GUI ValueRange:UtranFreqLayerMeasSwitch(UtranFreqLayerMeasSwitch),UtranFreqLayerBlindSwitch(UtranFreqLayerBlindSwitch)

Unit:None

Actual Value Range:UtranFreqLayerMeasSwitch,UtranFreqLayerBlindSwitch

Default Value:UtranFreqLayerMeasSwitch:Off,UtranFreqLayerBlindSwitch:Off

CSFallBackBlindHoCfgGeranLcsCap MODCSFALLBACKBLINDHOCFG


LOFD-001034 /TDLOFD-001034

LOFD-001047 /TDLOFD-001047

CS Fallbackto GERAN


Meaning:Indicates the Location Services (LCS) capability of theGERAN. If this parameter is set to ON, the GERAN supports LCS. Ifthis parameter is set to OFF, the GERAN does not support LCS.


Unit:None










http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/add_utrannfreq.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/mod_utrannfreq.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/lst_utrannfreq.html


http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/mod_enodebalgoswitch.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/lst_enodebalgoswitch.html






ENodeBAlgoSwitch HoAlgoSwitch MODENODEBALGOSWITCH


LBFD-00201801/TDLBFD-00201801

LBFD-00201802/TDLBFD-00201802

LOFD-001043 /TDLOFD-001043

LOFD-001046 /TDLOFD-001046

LBFD-00201805/TDLBFD-00201805

LOFD-001033 /TDLOFD-001033

LOFD-001034 /TDLOFD-001034

LOFD-001035 /TDLOFD-001035

LOFD-001052 /TDLOFD-001052

LOFD-001053 /TDLOFD-001053

CoverageBased Intra-frequencyHandover

CoverageBased Inter-frequencyHandover

Service basedinter-RAThandover toUTRAN

Service basedinter-RAThandover toGERAN

Service BasedInter-frequencyHandover

CS Fallbackto UTRAN

CS Fallbackto GERAN


Flash CSFallback toUTRAN

Flash CSFallback toGERAN

Meaning:Indicates the collective switch used to enable or disablehandover.

Flash CS fallback to UTRAN: If the switch for CS fallback to UTRAN isturned off, this switch does not take effect;

Flash CS fallback to GERAN: If the switch for CS fallback to GERAN isturned off, this switch does not take effect.

GUI Value Range:IntraFreqCoverHoSwitch(IntraFreqCoverHoSwitch),InterFreqCoverHoSwitch(InterFreqCoverHoSwitch),UtranCsfbSwitch(UtranCsfbSwitch),GeranCsfbSwitch(GeranCsfbSwitch),Cdma1xRttCsfbSwitch(Cdma20001xRttCsfbSwitch),UtranServiceHoSwitch(UtranServiceHoSwitch),GeranServiceHoSwitch(GeranServiceHoSwitch),CdmaHrpdServiceHoSwitch(Cdma2000HrpdServiceHoSwitch),Cdma1xRttServiceHoSwitch(Cdma20001xRttServiceHoSwitch),UlQualityInterRATHoSwitch(UlQualityInterRATHoSwitch),InterPlmnHoSwitch(InterPlmnHoSwitch),UtranFlashCsfbSwitch(UtranFlashCsfbSwitch),GeranFlashCsfbSwitch(GeranFlashCsfbSwitch),ServiceBasedInterFreqHoSwitch(ServiceBasedInterFreqHoSwitch),UlQualityInterFreqHoSwitch(UlQualityInterFreqHoSwitch)

Unit:None

Actual Value Range:IntraFreqCoverHoSwitch,InterFreqCoverHoSwitch, UtranCsfbSwitch, GeranCsfbSwitch,Cdma1xRttCsfbSwitch, UtranServiceHoSwitch,GeranServiceHoSwitch, CdmaHrpdServiceHoSwitch,Cdma1xRttServiceHoSwitch, UlQualityInterRATHoSwitch,InterPlmnHoSwitch, UtranFlashCsfbSwitch, GeranFlashCsfbSwitch,ServiceBasedInterFreqHoSwitch, UlQualityInterFreqHoSwitch

Default Value:IntraFreqCoverHoSwitch:On,InterFreqCoverHoSwitch:On, UtranCsfbSwitch:Off,GeranCsfbSwitch:Off, Cdma20001xRttCsfbSwitch:Off,UtranServiceHoSwitch:Off, GeranServiceHoSwitch:Off,Cdma2000HrpdServiceHoSwitch:Off,Cdma20001xRttServiceHoSwitch:Off, UlQualityInterRATHoSwitch:Off,InterPlmnHoSwitch:Off, UtranFlashCsfbSwitch:Off,GeranFlashCsfbSwitch:Off, ServiceBasedInterFreqHoSwitch:Off,UlQualityInterFreqHoSwitch:Off

ENodeBAlgoSwitch HoModeSwitch MODENODEBALGOSWITCH


LOFD-001019 /TDLOFD-001019

LOFD-001020 /TDLOFD-001020

LOFD-001021 /TDLOFD-001021

LOFD-001022 /TDLOFD-001022

LOFD-001023 /TDLOFD-001023

PS Inter-RATMobilitybetween E-UTRAN andUTRAN


PS Inter-RATMobilitybetween E-UTRAN andCDMA2000

SRVCC toUTRAN

SRVCC toGERAN

Meaning:Indicates the switches corresponding to the inputs based onwhich the eNodeB determines handover policies.

Note that EutranVoipCapSwitch will be removed in the later versions.In this version, the setting of this switch is still synchronized betweenthe M2000 and the eNodeB, but it is no longer used internally.Therefore, avoid using this switch.

GUI Value Range:EutranVoipCapSwitch(EutranVoipCapSwitch),UtranVoipCapSwitch(UtranVoipCapSwitch),GeranVoipCapSwitch(GeranVoipCapSwitch),Cdma1xRttVoipCapSwitch(Cdma1xRttVoipCapSwitch),UtranPsHoSwitch(UtranPsHoSwitch),GeranPsHoSwitch(GeranPsHoSwitch),CdmaHrpdNonOtpimisedHoSwitch(CdmaHrpdNonOtpimisedHoSwitch),CdmaHrpdOptimisedHoSwitch(CdmaHrpdOptimisedHoSwitch),GeranNaccSwitch(GeranNaccSwitch),GeranCcoSwitch(GeranCcoSwitch),UtranSrvccSwitch(UtranSrvccSwitch),GeranSrvccSwitch(GeranSrvccSwitch),Cdma1xRttSrvccSwitch(Cdma1xRttSrvccSwitch),UtranRedirectSwitch(UtranRedirectSwitch),GeranRedirectSwitch(GeranRedirectSwitch),CdmaHrpdRedirectSwitch(CdmaHrpdRedirectSwitch),Cdma1xRttRedirectSwitch(Cdma1xRttRedirectSwitch),BlindHoSwitch(BlindHoSwitch)

Unit:None

Actual Value Range:EutranVoipCapSwitch, UtranVoipCapSwitch,GeranVoipCapSwitch, Cdma1xRttVoipCapSwitch, UtranPsHoSwitch,GeranPsHoSwitch, CdmaHrpdNonOtpimisedHoSwitch,CdmaHrpdOptimisedHoSwitch, GeranNaccSwitch, GeranCcoSwitch,UtranSrvccSwitch, GeranSrvccSwitch, Cdma1xRttSrvccSwitch,UtranRedirectSwitch, GeranRedirectSwitch,CdmaHrpdRedirectSwitch, Cdma1xRttRedirectSwitch, BlindHoSwitch

Default Value:EutranVoipCapSwitch:On, UtranVoipCapSwitch:Off,GeranVoipCapSwitch:Off, Cdma1xRttVoipCapSwitch:Off,UtranPsHoSwitch:Off, GeranPsHoSwitch:Off,CdmaHrpdNonOtpimisedHoSwitch:Off,CdmaHrpdOptimisedHoSwitch:Off, GeranNaccSwitch:Off,GeranCcoSwitch:Off, UtranSrvccSwitch:Off, GeranSrvccSwitch:Off,Cdma1xRttSrvccSwitch:Off, UtranRedirectSwitch:Off,GeranRedirectSwitch:Off, CdmaHrpdRedirectSwitch:Off,Cdma1xRttRedirectSwitch:Off, BlindHoSwitch:Off









CSFallBackBlindHoCfgInterRatHighestPri MODCSFALLBACKBLINDHOCFG


LOFD-001019 /TDLOFD-001019

LOFD-001020 /TDLOFD-001020

LOFD-001021 /TDLOFD-001021

LOFD-001044 /TDLOFD-001044

LOFD-001045 /TDLOFD-001045

LOFD-001033 /TDLOFD-001033

LOFD-001034 /TDLOFD-001034

LOFD-001035 /TDLOFD-001035

LOFD-001068 /TDLOFD-001068

LOFD-001069 /TDLOFD-001069

LOFD-001052 /TDLOFD-001052

LOFD-001053 /TDLOFD-001053




Inter-RATLoad Sharingto UTRAN


CS Fallbackto UTRAN

CS Fallbackto GERAN


CS Fallbackwith LAI toUTRAN

CS Fallbackwith LAI toGERAN



Meaning:Ndicates the high-priority system to be considered in blindhandovers. It is UTRAN by default. This parameter can be set toUTRAN, GERAN, or CDMA2000.

GUI Value Range:UTRAN, GERAN, CDMA2000

Unit:None

Actual Value Range:UTRAN, GERAN, CDMA2000

Default Value:UTRAN

CSFallBackBlindHoCfgInterRatLowestPri MODCSFALLBACKBLINDHOCFG


LOFD-001019 /TDLOFD-001019

LOFD-001020 /TDLOFD-001020

LOFD-001021 /TDLOFD-001021

LOFD-001044 /TDLOFD-001044

LOFD-001045 /TDLOFD-001045

LOFD-001033 /TDLOFD-001033

LOFD-001034 /TDLOFD-001034

LOFD-001035 /TDLOFD-001035






CS Fallbackto UTRAN

CS Fallbackto GERAN



CS Fallback

Meaning:Indicates the low-priority system to be considered in blindhandovers. It is CDMA2000 by default. This parameter can be set toUTRAN, GERAN, or CDMA2000. If this parameter is set to NULL, thesystem with the medium blind handover priority is not specified only blind handovers to the high- and medium-priority systems areapplicable.

GUI Value Range:UTRAN, GERAN, CDMA2000, NULL

Unit:None

Actual Value Range:UTRAN, GERAN, CDMA2000, NULL

Default Value:CDMA2000









LOFD-001068 /TDLOFD-001068

LOFD-001069 /TDLOFD-001069

LOFD-001052 /TDLOFD-001052

LOFD-001053 /TDLOFD-001053

with LAI toGERAN



CSFallBackBlindHoCfgInterRatSecondPri MODCSFALLBACKBLINDHOCFG


LOFD-001019 /TDLOFD-001019

LOFD-001020 /TDLOFD-001020

LOFD-001021 /TDLOFD-001021

LOFD-001044 /TDLOFD-001044

LOFD-001045 /TDLOFD-001045

LOFD-001033 /TDLOFD-001033

LOFD-001034 /TDLOFD-001034

LOFD-001035 /TDLOFD-001035

LOFD-001068 /TDLOFD-001068

LOFD-001069 /TDLOFD-001069

LOFD-001052 /TDLOFD-001052

LOFD-001053 /TDLOFD-001053






CS Fallbackto UTRAN

CS Fallbackto GERAN



CS Fallbackwith LAI toGERAN



Meaning:Indicates the medium-priority system to be considered inblind handovers. It is GERAN by default. This parameter can be set toUTRAN, GERAN, or CDMA2000. If this parameter is set to NULL, thesystem with the medium blind handover priority is not specified only blind handovers to the high-priority system are applicable.

GUI Value Range:UTRAN, GERAN, CDMA2000, NULL

Unit:None

Actual Value Range:UTRAN, GERAN, CDMA2000, NULL

Default Value:GERAN

CSFallBackHo LocalCellId LST CSFALLBACKHO

MOD CSFALLBACKHO

LBFD-001001 /TDLBFD-001001

3GPP R8Specifications

Meaning:Indicates the local ID of the cell. It uniquely identifies a cellwithin a BS.


Unit:None


Default Value:None

S1Interface MmeRelease ADD S1INTERFACE

MOD S1INTERFACE

DSP S1INTERFACE

LBFD-001001 /TDLBFD-001001

3GPP R8Specifications

Meaning:Indicates the compliance protocol release of the MME towhich the eNodeB is connected through the S1 interface. The valueof this parameter must be the same as the MME-complied protocolrelease. The eNodeB sends S1 messages complying with theprotocol release specified by this parameter. If the parameter value isdifferent from the MME-complied protocol release, the way in whichthe MME handles these message is subject to the MMEimplementation.

GUI Value Range:Release_R8(Release 8), Release_R9(Release 9),Release_R10(Release 10)




http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/para/CSFallBackHo-LocalCellId.html




http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/add_s1interface.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/mod_s1interface.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/dsp_s1interface.html



Unit:None

Actual Value Range:Release_R8, Release_R9, Release_R10

Default Value:Release_R8(Release 8)

UtranExternalCell Rac ADDUTRANEXTERNALCELL

MODUTRANEXTERNALCELL

LSTUTRANEXTERNALCELL

LOFD-001019 /TDLOFD-001019


Meaning:Indicates the routing area code.


Unit:None


Default Value:0

GeranExternalCell Rac ADDGERANEXTERNALCELL

MODGERANEXTERNALCELL

LSTGERANEXTERNALCELL

LOFD-001020 /TDLOFD-001020


Meaning:Indicates the routing area code.


Unit:None


Default Value:0

ENodeBAlgoSwitch RimSwitch MODENODEBALGOSWITCH


LOFD-001052 /TDLOFD-001052

LOFD-001053 /TDLOFD-001053



Meaning:Indicates the collective switch for the RAN informationmanagement (RIM) function.

UTRAN_RIM_SWITCH: Indicates the switch used to enable or disablethe RIM procedure that requests event-driven multiple reports fromUTRAN cells.

If this switch is turned on, the eNodeB can send RAN-INFORMATION-REQUEST protocol data units (PDUs) to UTRAN cells to requestmultiple event-driven reports.

If this switch is turned off, the eNodeB cannot send RAN-INFORMATION-REQUEST PDUs to UTRAN cells to request multipleevent-driven reports.

GERAN_RIM_SWITCH: Indicates the switch used to enable or disablethe RIM procedure that requests event-driven multiple reports fromGERAN cells.

If this switch is turned on, the eNodeB can send RAN-INFORMATION-REQUEST PDUs to CERAN cells to request multiple event-drivenreports.

If this switch is turned off, the eNodeB cannot send RAN-INFORMATION-REQUEST PDUs to GERAN cells to request multipleevent-driven reports.

GUI Value Range:UTRAN_RIM_SWITCH(UTRAN RIM Switch),GERAN_RIM_SWITCH(GERAN RIM Switch)

Unit:None

Actual Value Range:UTRAN_RIM_SWITCH, GERAN_RIM_SWITCH

Default Value:UTRAN RIM Switch:Off, GERAN RIM Switch:Off

CSFallBackBlindHoCfgUtranLcsCap MODCSFALLBACKBLINDHOCFG


LOFD-001033 /TDLOFD-001033

LOFD-001047 /TDLOFD-001047

CS Fallbackto UTRAN


Meaning:Indicates the Location Services (LCS) capability of theUTRAN. If this parameter is set to ON, the UTRAN supports LCS. Ifthis parameter is set to OFF, the UTRAN does not support LCS.


Unit:None



9 Counters

Table 9-1 Counter description

Counter ID Counter Name Counter Description Feature ID Feature Name

1526726988 L.IRATHO.E2C.ExecSuccOut Number of SuccessfulOutgoing Handovers from E-UTRAN to CDMA2000

LOFD-001021

LOFD-001035

PS Inter-RAT Mobility betweenE-UTRAN and CDMA2000

CS Fallback to CDMA20001xRTT

1526726989 L.IRATHO.E2W.PrepAttOut Number of OutgoingHandover Attempts from E-UTRAN to UTRAN

LOFD-001019

LOFD-001022

LOFD-001033

TDLOFD-001019

TDLOFD-001022

TDLOFD-001033

PS Inter-RAT Mobility betweenE-UTRAN and UTRAN

SRVCC to UTRAN

CS Fallback to UTRAN


SRVCC to UTRAN


1526726990 L.IRATHO.E2W.ExecAttOut Number of Performed LOFD-001019 PS Inter-RAT Mobility between


http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/add_utranexternalcell.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/mod_utranexternalcell.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/lst_utranexternalcell.html


http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/add_geranexternalcell.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/mod_geranexternalcell.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/mml/lst_geranexternalcell.html







http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/lte/lte-enodeb-performance-counter-reference/MT_L_IRATHO_E2C_SuccOut.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/lte/lte-enodeb-performance-counter-reference/MT_L_IRATHO_E2W_AttOut.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/lte/lte-enodeb-performance-counter-reference/MT_L_IRATHO_E2W_PerOut.html



Outgoing Handovers from E-UTRAN to UTRAN LOFD-001022

LOFD-001033

TDLOFD-001019

TDLOFD-001022

TDLOFD-001033

E-UTRAN and UTRAN

SRVCC to UTRAN



SRVCC to UTRAN


1526726991 L.IRATHO.E2W.ExecSuccOut Number of SuccessfulOutgoing Handovers from E-UTRAN to UTRAN

LOFD-001019

LOFD-001022

LOFD-001033

TDLOFD-001019

TDLOFD-001022

TDLOFD-001033


SRVCC to UTRAN



SRVCC to UTRAN


1526726992 L.IRATHO.E2G.PrepAttOut Number of OutgoingHandover Attempts from E-UTRAN to GERAN

LOFD-001020

LOFD-001023

LOFD-001034

TDLOFD-001020

TDLOFD-001023

TDLOFD-001034

PS Inter-RAT Mobility betweenE-UTRAN and GERAN

SRVCC to GERAN

CS Fallback to GERAN


SRVCC to GERAN


1526726993 L.IRATHO.E2G.ExecAttOut Number of PerformedOutgoing Handovers from E-UTRAN to GERAN

LOFD-001020

LOFD-001023

LOFD-001034

TDLOFD-001020

TDLOFD-001023

TDLOFD-001034


SRVCC to GERAN



SRVCC to GERAN


1526726994 L.IRATHO.E2G.ExecSuccOut Number of SuccessfulOutgoing Handovers from E-UTRAN to GERAN

LOFD-001020

LOFD-001023

LOFD-001034

TDLOFD-001020

TDLOFD-001023

TDLOFD-001034


SRVCC to GERAN



SRVCC to GERAN


1526727033 Handover from E-UTRAN to CDMA2000Success Rate

Success rate of inter-RAThandovers from E-UTRAN toCDMA2000 network

LOFD-001021

LOFD-001035

PS Inter-RAT Mobility betweenE-UTRAN and CDMA2000


1526727034 Handover from E-UTRAN to WCDMASuccess Rate

Success rate of inter-RAThandovers from E-UTRAN toWCDMA network

LOFD-001019

LOFD-001022

LOFD-001033

TDLOFD-001019

TDLOFD-001022

TDLOFD-001033


SRVCC to UTRAN



SRVCC to UTRAN


1526728306 L.IRATHO.E2G.Prep.FailOut.MME Number of outgoing handoverpreparation failures from E-UTRAN to GERAN due tofaults in the EPC

LOFD-001034

TDLOFD-001034

LOFD-001020

TDLOFD-001020

LOFD-001046

TDLOFD-001046

LOFD-001073





Service based inter-RAThandover to GERAN


Distance based inter-RAT

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/lte/lte-enodeb-performance-counter-reference/MT_L_IRATHO_E2W_SuccOut.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/lte/lte-enodeb-performance-counter-reference/MT_L_IRATHO_E2G_AttOut.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/lte/lte-enodeb-performance-counter-reference/MT_L_IRATHO_E2G_PerOut.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/lte/lte-enodeb-performance-counter-reference/MT_L_IRATHO_E2G_SuccOut.html

http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/lte/lte-enodeb-performance-counter-reference/MtType_366.html





handover to GERAN

1526728307 L.IRATHO.E2G.Prep.FailOut.NoReply Number of outgoing handoverpreparation failures due to noresponses from GERAN

LOFD-001034

TDLOFD-001034

LOFD-001020

TDLOFD-001020

LOFD-001046

TDLOFD-001046

LOFD-001073







Distance based inter-RAThandover to GERAN

1526728308 L.IRATHO.E2G.Prep.FailOut.PrepFailure Number of outgoing handoverpreparation failures due tohandover preparation failuresin GERAN

LOFD-001034

TDLOFD-001034

LOFD-001020

TDLOFD-001020

LOFD-001046

TDLOFD-001046

LOFD-001073








1526728309 L.IRATHO.E2T.Prep.FailOut.MME Number of outgoing handoverpreparation failures from E-UTRAN to TD-SCDMAnetwork due to faults in theEPC

LOFD-001033

TDLOFD-001033

LOFD-001019

TDLOFD-001019

LOFD-001043

TDLOFD-001043

LOFD-001072





Service based inter-RAThandover to UTRAN


Distance based inter-RAThandover to UTRAN

1526728310 L.IRATHO.E2T.Prep.FailOut.NoReply Number of outgoing handoverpreparation failures due to noresponses from TD-SCDMAnetwork

LOFD-001033

TDLOFD-001033

LOFD-001019

TDLOFD-001019

LOFD-001043

TDLOFD-001043

LOFD-001072








1526728311 L.IRATHO.E2T.Prep.FailOut.PrepFailure Number of outgoing handoverpreparation failures due tohandover preparation failuresin TD-SCDMA network

LOFD-001033

TDLOFD-001033

LOFD-001019

TDLOFD-001019

LOFD-001043

TDLOFD-001043

LOFD-001072








1526728312 L.IRATHO.BlindHO.E2W.ExecAttOut Number of performedoutgoing blind handoversfrom E-UTRAN to

WCDMA network

LOFD-001033

TDLOFD-001033

LOFD-001019

TDLOFD-001019




PS Inter-RAT Mobility between

E-UTRAN and UTRAN









1526728313 L.IRATHO.BlindHO.E2W.ExecSuccOut Number of performedoutgoing blind handoversfrom E-UTRAN to

WCDMA network

LOFD-001033

TDLOFD-001033

LOFD-001019

TDLOFD-001019





1526728314 L.IRATHO.BlindHO.E2G.ExecAttOut Number of performedoutgoing blind handoversfrom E-UTRAN to

GERAN

LOFD-001034

TDLOFD-001034

LOFD-001020

TDLOFD-001020





1526728315 L.IRATHO.BlindHO.E2G.ExecSuccOut Number of successfuloutgoing blind handoversfrom E-UTRAN to GERAN

LOFD-001034

TDLOFD-001034

LOFD-001020

TDLOFD-001020





1526728316 L.IRATHO.E2W.Prep.FailOut.MME Number of outgoing handoverpreparation failures from E-UTRAN to WCDMA networkdue to faults in the EPC

LOFD-001033

TDLOFD-001033

LOFD-001019

TDLOFD-001019

LOFD-001043

TDLOFD-001043

LOFD-001072








1526728317 L.IRATHO.E2W.Prep.FailOut.PrepFailureNumber of outgoing handoverpreparation failures due tohandover preparation failuresin WCDMA network

LOFD-001033

TDLOFD-001033

LOFD-001019

TDLOFD-001019

LOFD-001043

TDLOFD-001043

LOFD-001072








1526728318 L.IRATHO.E2W.Prep.FailOut.NoReply Number of outgoing handoverpreparation failures due to noresponses from WCDMAnetwork

LOFD-001033

TDLOFD-001033

LOFD-001019

TDLOFD-001019

LOFD-001043

TDLOFD-001043

LOFD-001072








1526728321 L.CSFB.PrepAtt Number of CS fallbackindicators received by theeNodeB

LOFD-001033

TDLOFD-001033

LOFD-001034

TDLOFD-001034

LOFD-001035






1526728322 L.CSFB.PrepSucc Number of successful CSfallback responses from theeNodeB

LOFD-001033

TDLOFD-001033

LOFD-001034














TDLOFD-001034

LOFD-001035



1526728323 L.CSFB.E2W Number of CS fallbackprocedures from E-UTRAN toUTRAN<?Pub

Caret?>

LOFD-001033

TDLOFD-001033



1526728324 L.CSFB.E2G Number of CS fallbackprocedures from E-UTRAN toGERAN

LOFD-001034

TDLOFD-001034



1526728326 L.RRCRedirection.E2W Number of redirections toWCDMA network

LOFD-001033

TDLOFD-001033

LOFD-001052

TDLOFD-001052

LOFD-001019

TDLOFD-001019

LOFD-001072

LOFD-001043

TDLOFD-001043



Flash CS Fallback to UTRAN







1526728327 L.RRCRedirection.E2G Number of redirections toGERAN

LOFD-001034

TDLOFD-001034

LOFD-001053

TDLOFD-001053

LOFD-001020

TDLOFD-001020

LOFD-001073

LOFD-001046

TDLOFD-001046










1526728328 L.IRATHO.BlindHO.E2W.PrepAttOut Number of outgoing blindhandover attempts from E-UTRAN to

WCDMA network

LOFD-001033

TDLOFD-001033

LOFD-001019

TDLOFD-001019





1526728329 L.IRATHO.BlindHO.E2G.PrepAttOut Number of outgoing blindhandover attempts from E-UTRAN to

GERAN

LOFD-001034

TDLOFD-001034

LOFD-001020

TDLOFD-001020





1526728330 L.RRCRedirection.E2W.PrepAtt Number of redirectionpreparations to WCDMAnetwork

LOFD-001033

TDLOFD-001033

LOFD-001052

TDLOFD-001052

LOFD-001019

TDLOFD-001019

LOFD-001072

LOFD-001043

TDLOFD-001043









Service based inter-RAT










handover to UTRAN

1526728331 L.RRCRedirection.E2G.PrepAtt Number of redirectionpreparations to GERAN

LOFD-001034

TDLOFD-001034

LOFD-001053

TDLOFD-001053

LOFD-001020

TDLOFD-001020

LOFD-001073

LOFD-001046

TDLOFD-001046










10 Glossary

For the acronyms, abbreviations, terms, and definitions, see Glossary.

11 Reference Documents

This chapter lists the reference documents related to CSFB:

[1] 3GPP TS 23.272, "Circuit Switched (CS) fallback in Evolved Packet System (EPS)"

[2] 3GPP TS 23.216, "Single Radio Voice Call Continuity (SRVCC); Stage 2"

[3] VoLGA Forum Specifications

[4] 3GPP TS 36.300, "E-UTRAN Overall description"

[5] 3GPP TS 23.401, "General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access"

[6] 3GPP TS 48.018, "General Packet Radio Service (GPRS); Base Station System (BSS)-Serving GPRS Support Node (SGSN); BSS GPRS Protocol (BSSGP)"

[7] eNodeB MO Reference

[8] eNodeB Performance Counter Reference

[9] Mobility Management in Connected Mode Feature Parameter Description

[10] Idle Mode Management Feature Parameter Description

[11] eNodeB Initial Configuration Guide

[12] eNodeB Reconfiguration Guide


http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/lte/f-enodeb-glossary/ff-7-glossary.html


http://localhost:7890/pages/GEB0110E/08/GEB0110E/08/resources/Description/Idle%20Mode%20Management.htm

huawei eran feature documentation

Documents

csfb procedures

emergency calls4 csfb

mobileoriginated calls3

emergency calls3

huawei trademarks

measurement phase of

preregistration procedure3

execution phase of csfb4