Mobility Between UMTS and LTE

WCDMA RAN

Mobility Between UMTS and LTE Feature Parameter Description

Copyright © Huawei Technologies Co., Ltd. 2011. 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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WCDMA RAN Mobility Between UMTS and LTE

Contents

Contents 1 Introduction ................................................................................................................................1-1 1.1 Scope ............................................................................................................................................ 1-1 1.2 Intended Audience ........................................................................................................................ 1-1 1.3 Change History.............................................................................................................................. 1-1

2 Overview .....................................................................................................................................2-1 3 Cell Selection and Reselection .............................................................................................3-1 3.1 Overview ....................................................................................................................................... 3-1 3.2 Cell Reselection Procedure........................................................................................................... 3-1 3.3 Measurement Criteria .................................................................................................................... 3-1 3.4 Cell Reselection Criteria ................................................................................................................ 3-1 3.5 System Information Block Type 19................................................................................................ 3-2

4 Service-Based PS Service Redirection from UMTS to LTE ...........................................4-1 4.1 Overview ....................................................................................................................................... 4-1 4.2 Triggering ...................................................................................................................................... 4-1 4.3 Measurement ................................................................................................................................ 4-2 4.4 Decision and Execution ................................................................................................................. 4-2

5 Engineering Guidelines...........................................................................................................5-3 5.1 Typical Scenarios .......................................................................................................................... 5-3 5.2 Main Factors Affecting This Feature ............................................................................................. 5-3 5.3 Suggestions for Deploying This Feature ....................................................................................... 5-3 5.4 Performance Monitoring ................................................................................................................ 5-3

6 Parameters .................................................................................................................................6-1 7 Counters ......................................................................................................................................7-1 8 Glossary ......................................................................................................................................8-1 9 Reference Documents .............................................................................................................9-1

Issue 01 (2011-04-30)

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i

WCDMA RAN Mobility Between UMTS and LTE

1 Introduction

1 Introduction 1.1 Scope This document describes the feature Mobility Between UMTS and LTE.

1.2 Intended Audience This document is intended for: 

Personnel who are familiar with WCDMA basics



Personnel who need to understand Mobility Between UMTS and LTE



Personnel who work with Huawei products

1.3 Change History This section provides information on the changes in different document versions. There are two types of change, which are defined as follows: 

Feature change: refers to a change in the feature Mobility Between UMTS and LTE.



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

Document Issue The document issues are as follows: 

01 (2011-04-30)



Draft B (2011-03-30)



Draft A (2010-12-30)

01 (2011-04-30) This is the document for the first commercial release of RAN13.0. Compared with issue Draft B (2011-03-30) of RAN13.0, this issue has no change.

Draft B (2011-03-30) This is the draft of the document for RAN13.0. Compared with Draft A (2010-12-30) of RAN13.0, engineering guidelines is added. For details, see 5 “Engineering Guidelines. ”

Draft A (2010-12-30) This is the draft of the document. Compared with issue 01 (2010-03-30) of RAN12.0, this issue incorporates the changes described in the following table:

Issue 01 (2011-04-30)

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1-1

WCDMA RAN Mobility Between UMTS and LTE

1 Introduction

Change Type

Change Description

Parameter Change

Feature change

Descriptions about Service-Based PS service redirection from UMTS to LTE are added. For details, see chapter 4 "Service-Based PS Service Redirection from UMTS to LTE."

The following parameters are added:

Editorial change

None.

Issue 01 (2011-04-30)



EUTRANSHIND



LTEMeasTypOf3C



LTEMeasQuanOf3C



TrigTime3C



U2LTEMeasTime



SuppPSHOFlag



U2LTEFilterCoef



TargetRatThdRSRP



TargetRatThdRSRQ



Hystfor3C

None.

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1-2

WCDMA RAN Mobility Between UMTS and LTE

2 Overview

2 Overview Long-Term Evolution (LTE) is a technology that evolves from Universal Mobile Telecommunications System (UMTS). LTE is gaining momentum to dominate the mobile communications networks. During the initial stage of LTE network deployment, it is difficult to provide seamless LTE coverage in the entire network. To solve this problem, the feature Mobility Between UMTS and LTE (WRFD-020126 Mobility Between UMTS and LTE Phase 1) is introduced. With this feature, a UE supporting both UMTS and LTE can obtain higher rates in areas covered by both UMTS and LTE. In addition, the UMTS network can take over LTE UEs in areas where the LTE network does not provide coverage or the LTE network capacity is not enough. The feature protects investments on the existing network, improves the quality of service (QoS), and enables smooth network evolution. In a common initial deployment scenario, an LTE network provides high-rate mobile broadband services in hotspots, whereas a UMTS network provides low- and medium-rate mobile broadband services and seamless coverage in wide areas. RAN12.0 supports: 

Cell reselection from UMTS to LTE



Cell reselection from LTE to UMTS (see the LTE Feature Documentation)



Handover from LTE to UMTS for coverage (see the LTE Feature Documentation)

RAN13.0 supports: 

PS service redirection from UMTS to LTE

Issue 01 (2011-04-30)

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2-1

WCDMA RAN Mobility Between UMTS and LTE

3 Cell Selection and Reselection

3 Cell Selection and Reselection 3.1 Overview When a UE is powered on, it initially selects a public land mobile network (PLMN) based on the radio access technology (RAT) priorities of PLMNs stored in its SIM card. If the UE receives system information block type 19 (SIB19) from a UMTS network, it selects a PLMN based on the RAT priorities of PLMNs included in SIB19. Otherwise, it remains in the current PLMN. In the UMTS network, SIB19 includes the absolute priority of the serving cell and the absolute priority of each LTE frequency. When an LTE frequency has a higher absolute priority than the serving cell, the UE reselects an LTE cell on this frequency if other conditions for LTE cell reselection are also met. When the absolute priority of each LTE frequency is lower than that of the serving cell, the UE reselects another UMTS cell if other conditions for UMTS cell reselection are also met. In the LTE network, SIB3 includes the absolute priority of the serving cell, SIB5 includes the absolute priority of each LTE frequency, and SIB6 includes the absolute priority of each UMTS frequency. Based on these priorities, a UE can determine whether to select/reselect a UMTS cell or an LTE cell.

3.2 Cell Reselection Procedure Based on signal quality of neighboring cells, the UE determines whether to reselect a neighboring cell. For details about the cell reselection procedure, see the UE Behaviors in Idle Feature Parameter Description.

3.3 Measurement Criteria The design of radio resource management (RRM) is closely related to the measurement procedure and measurement results. If the absolute priorities of LTE frequencies are configured for the serving cell, these priorities must be different from the absolute priority of the serving cell. In this case, the criteria for triggering inter-RAT measurement are as follows: 

If some neighboring LTE cells have higher absolute priorities than the serving cell, the UE measures these LTE cells.



If some neighboring LTE cells have lower absolute priorities than the serving cell, the UE measures these LTE cells under the condition SrxlevServingCell