GUL Interoperability Overview

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GUL Interoperability Overview


Objectives

Upon completion of this course, you will be able to:

Describe GUL Interoperability Networking Strategy

Understand GUL Interoperability Networking Strategy

Outline GUL Interoperability Performance Estimation

Know Interoperability Ecosystem Developing

Page3


Contents

1. GUL Interoperability Overview

2. GUL Interoperability Networking Strategy

3. GUL Interoperability Solution

4. GUL Interoperability Performance Estimation

5. GUL Interoperability Ecosystem Developing

Page4


LTE Network Challenges

Indu

stry

Cha

in

Mat

urity

Customer

Experience

Ecosystem In

vest

men

t

Rewar

d

LTE Challenges

Risk of Customer Experience• Voice & SMS on LTE

• Seamless Handover between

G/U/L

Maturity Bottleneck• Lack of End to End Solution

Provider• Lack of Network Deployment

Experience• Terminals

Economical LTE Rollout• Flexible Site Solution• Cost-effective Backhaul Solution • Easy O&M

Profit-Oriented Approach • Service Innovation Create

Customer Value• Flexible Third Party Cooperation

Mechanism

LTE is the future, but opportunities always stay with challenges

Page5


Operator’s Main Concerns

Impact of LTE introduction

Technology selection for different services;

Change on existing NE.

High end user experience QoE of new LTE subs;

Service continuity and

diversity.

GSM/UMTS/LTE Interoperability

Ecosystem’s maturity Spectrum availability;

UE availability;

Data service first.

Efficiency of investmentFocus on hotspot and dense

urban in initial phase.

Page6


Function Requirement for Interoperability from Operators

Minimum Influence GSM/UMTS provide voice service to make up the

deficiency of LTE service type Make use of GSM/UMTS to share the load of LTE

service Make UEs in low data service rate handover to

GSM/ UMTS system, raising GSM/UMTS system

utilization ratio and, exerting LTE high-speed data

service advantage

Reasonable Inter-system Service/Load-sharing

GSM/UMTS is required to compensate the lack of LTE coverage

Try to receive data services as

far as possible in LTE so as to

get the best business

experience

The Best Service Experience

Impose the minimum influence

on networks and subscribes

during network upgrading

Ensure Service Continuity

Page7


Performance Requirements for Interoperability from Operators

…

Satisfy KPI

IRAT Interoperability success

rate

IRAT Interoperability time delay

Require High Speed Service

Experience

Service experience trend ：LTE > UMTS > GSM

Set IRAT parameters

reasonably

Avoid IRAT ping-pang

handover/reselectionPerformance Requirements

Page8


LTE Deployment Strategy

Urban / Rural in expanding / mature phase

More spectrum available Convergent PS Core Load sharing strategy Service based mobility Enhance Network performance and end

user experience

Enable seamless service experience between LTE and G/U systems

Limited spectrum options Mainly dedicated for data service Independent EPC to minimize impact on CN Keep service continuity via 2G/3G network No impact on the stability of 2G/3G network

Hot spot / Dense Urban in initial phase

Page9


Network interworking design Connected state

U2100U2100

U900/850U900/850

GSM900/1800GSM900/1800

L1800L1800

• Handover based on coverage （ CS handover/PS Cell change ）

• PS reselection based on coverage (G->U)

• Handover based on coverage （ CS handover/PS Cell change ） (U900 edge area)

• CSFB （ L->U ， L->G)• PS handover/CCO/redirection based

on coverage （ L->U ， L->G)

• Inter-Freq handover based on coverage( UMTS center)

• Dual Inter-Freq handover based on coverage （ U900 edge area)

• PS handover/redirection based on service （ U->L)

U2100U2100

GSM900/1800GSM900/1800

Idle state

• Reselection • Camp on high priority

techonology first(LTE with the highest priority in default situation);

• Camp on low priority technology by coverage based reselection

L1800L1800

U900/850U900/850

Best QoS

Seamless Mobility Continuous service

Load balance

IDLE

CONNECTED

Camp/Cell Selection

Cell Reselection

Data Service

Continuity

Voice Service

Continuity

CS Fall Back

CCO

SRVCC

Handover/Redirection

Page10


Two Optional Network Structures for Interworking (Gn/Gp, S3/S4)

GGSN/PGW

MME

HSS

LTE TDD/FDD eNodeB

UMTS NodeB

GSMBTS

BSC

RNC

SGSN

S1u

S1-MME

S5

S11

S6a

S4

IP Servicese.g. IMS, PSS, etc

SGi

Gb

Gr

S3

S8

Gp

Lu-CS

A

S12

SGs/Sv

To Foreign PLMN

To Foreign PLMN

Gn

Gn

Lu-PS

To MME S10SGs

Proxy

• Fast to market.• Connect to the EPC with only minor change to

installed network.• Implement Gn/Gp structure in the first phase of LTE

deployment.• NE: GGSN should be upgraded or replaced or

integrated with PGW.• Gn/Gp is the most applied structure due to legacy

2G/3G version.

• Simple architecture• PCC, E2E QoE and GTP V2 is introduced.• This architecture will deployed when LTE

services obviously increased.• NE: SGSN, GGSN, MSC needs to be

upgraded.

Interfaces for S3/S4 structure

Interfaces for Gn/Gp structure

Advantage of Option 1: Gn/Gp (GTP V1) Advantage of Option 2: S3/S4 (GTP V2 )

Affected NE while implementing LTE

SGW

MSC/ VLR/eMSC

(GUL Scenario)

Page11


GUL Interworking Procedure with Scenes

Access Flow Flow Scenario Trigger Scenario Protocol reference

GnGp SGSN

Routing Area Update

MME to Gn/Gp SGSN Routing Area Update

• Cell reselection, PLMN reselection

•RRC Release and redirection•Cell Change Order•Cell Change Order with NACC

3GPP TS23.401 section Appendix D3GPP TS23.401 section 5.6

Tracking Area Update

Gn/Gp SGSN to MME Tracking Area Update

•Cell reselection, PLMN reselection•RRC release and redirection• TCH/SDCCH release and redirection

•Cell Change Order•Cell Change Order with NACC

3GPP TS23.401 section Appendix D3GPP TS23.401 section 5.6

Handover

MME to Gn/Gp SGSN handover

• Cover Based, loading based, service based (CSFB&SRVCC)

3GPP TS23.401 section Appendix D

Gn/Gp SGSN to MME handover

• Cover Based, loading based 3GPP TS23.401 section Appendix D

Page12


GUL Interworking Procedure with Scenes

Access Flow Flow Scenario Trigger Scenario Protocol reference

S4 SGSN

Tracking Area Update

E-UTRAN Tracking Area Update

• Cell reselection, PLMN reselection,

• RRC Release and redirection.• Cell Change Order.• Cell Change Order with NACC

3GPP TS23.401 section 5.3.3,5.6

Routing Area Update

UTRAN/GERAN Routing Area Update

• Cell reselection, PLMN reselection,

• RRC release and Redirection• TCH/SDCCH Release and Redirection

• Cell Change Order• Cell Change Order with NACC

3GPP TS23.401 section 5.3.3,5.6

Handover

E-UTRAN to UTRAN/GERAN Inter RAT handover

• Cover Based, loading based, service based (CSFB&SRVCC)

3GPP TS23.401 section 5.5.2

UTRAN/GERAN to E-UTRAN Inter RAT handover

• Cover Based, loading based 3GPP TS23.401 section 5.5.2

Page13


Standard of Interworking Progress

20082009

2011

R8EPC, LTE TDD/FDD

DefinedGUL,TDSL,CL

Interworking Defined VoLTE;

CSFB, SRVCC

R9eCSFB

(Flash CSFB)

R10GUL TL eSRVCCGUL TL aSRVCC

R11GUL TL rSRVCC

OSCARVoLTE RoamingCL MOCN IWK

Page14


Contents



2.1 Interoperability Networking Requirement Overview from

Operators

2.2 Interoperability Networking Scenarios and Strategies




Page15


Operator Requirements Overview for Interoperability Networking

GL Networkin

g

UL Networking

GUL Networkin

g

Germany TMO: Legacy network:GSM900 and UMTS2100, plans to

launch a LTE network in 800M and 1800M respectively ， UMTS

completely disappears, therefore forming GL Network scenario.

Canada Bell/Telus ： Continously coverage areas via UMTS850 and UMTS1900 , plan

to introduce LTE to co-existed expansion building, therefore forming UL Network

scenario.

HongKong Genius ： MOCN of HUT and PCCW. Legacy network: UMTS system

respectively owned by HUT and PCCW.

Singapore M1 ： Current GSM1800 exits to provide 10M available for LTE, and last

GSM completely disappears, thereby considering UL Network scenario.

Japan eMobile ： currently there are two carriers available for UMTS, 10M available for

LTE. Plans to provide 5M of UMTS for LTE via refarming so as to form UL Network

scenario.

Sweden N4M ： LTE possibly uses 2600/1800/800 ， UMTS occupies

2100/900 ， GSM 1800/900, existed UMTS can not form continuous

coverage areas, so GUL Network scenario appears.

Page16


Interoperability General Strategy(1/2) Preferentially camp on LTE frequency band

Reselect and handover from LTE edge area to GU network

Before deploying VoIP ， voice call falls back to GU network via

CSFB strategy

Reduce the difficulty of LTE configuration via a brief and efficient

strategy. Via existed GU interoperability strategy, LTE can

interoperate with one of GU frequency bands( or carriers) .

Page17


Interoperability General Strategy(2/2)

Phase 1: LTE Initial Deployment with Limited Coverage & subscribers in hotpot/dense urban

• LTE Mainly dedicated for data service• Voice Service Continuity via CSFB to 2G/3G

network• Keep service continuity via 2G/3G network by

coverage based Interworking• Load balance within LTE

Phase 2 and after: LTE with expanded Coverage & more subscribers in urban/rural

• Use PS handover for inter-RAT

switching

• Introduce VoLTE, voice continuity with

2G/3G via SRVCC

• Load balance between LTE and 3G/2G

LTE

G/U/T(Data)

G/U/T(Voice)

CSFB RedirectionReselection

LTE

G/U/T(Data)

G/U/T(Voice)

SRVCC RedirectionPSHOReselection

Camping by default Camping by default

Load Balance

VoLTE

Different interoperability strategies are adoptable in various LTE de-ployment phases

Page18


GL Networking Strategy （ 1/2 ）

1 ） Camping priority: LTE > GSM

2 ） Support cell reselection between

LTE and GSM

Supports LTE->GSM reselection at

the edge of LTE network;

Supports GSM ->LTE reselection

when moving into LTE coverage

area.

1 ） Supports LTE-> GSM coverage-based handover

2 ） Supports LTE-> GSM handover types ： PSHO, SRVCC,

CCO/NACC, Redirection.

PSHO can ensure PS continuity before and after

handover;

CCO/NACC and Redirection are suitable for PS, which

requires low time delay;

VoIP is deployed in LTE not in GSM, so SRVCC is

used to handover VoIP to GSM CS domain;

In GSM connection mode, UE does not support inter-

RAT measurement, then it will adaptively adopt

handover without measurement which need configure

blind priorities of neighbour cells of GSM cells

3 ） Quick redirection, NACCor Flash CSFB. It requires

network side to support RIM procedure

Idle Mode Connection Mode

Page19


GL Networking Strategy （ 2/2 ）

1 ） Supports LTE-> GSM load-

control-based redirection

Redirect UE to GSM when

overload occurs in a cell

2 ） Supports LTE-> GSM load-

based handover

Let certain services with a

specifics QCI (such as VoIP)

fall back to GSM

1 ） Before LTE supports VoIP, Voice service falls back to

GSM via CSFB

In GSM connection mode, UE does not support

inter-RAT measurement, then it will adaptively uses

CSFB without measurement which need configure

blind priorities of neighbour cells of GERAN cells

In case of unspecific GSM handover function

supported by the network and UEs, only enable the

switch of redirection.

2 ） If VoIP is deployed in LTE not in GSM, SRVCC is

applied at the edge of LTE network so as to handover

voice service to GSM CS domain.

3 ） If VoIP is deployed in both LTE and GSM, PSHO is

adopted at the edge of LTE network so as to

handover VoIP service to GSM network.

Load Control and service steering Voice Solution

Page20


UL Networking Strategy （ 1/2 ）

1 ） Camping priority: LTE > UMTS

2 ） Support cell reselection between

LTE and UMTS

Supports LTE-> UMTS reselection at

the edge of LTE network;

Supports UMTS ->LTE reselection

when moving into LTE coverage

area.

1 ） Supports LTE-> UMTS coverage-based handover

2 ） Supports LTE-> UMTS handover types:

PSHO ， SRVCC ， Redirection 。 PSHO can ensure PS continuity before and after

handover;

Redirection is suitable for PS, which requires low

delay;

VoIP is deployed in LTE not in UMTS, so SRVCC is

used to handover VoIP to UMTS CS domain;

In UMTS connection mode, UE does not support inter-

RAT measurement, then it will adaptively adopt

handover without measurement which need configure

blind priorities of neighbour cells of UMTS cells

3 ） Quick redirection and flash CSFB. It requires network

side to support RIM procedure

Idle Mode Connection Mode

Page21


UL Networking Strategy （ 2/2 ）

1 ） Supports LTE-> UMTS load-control-

based redirection

Redirect UE to UMTS when overload

occurs in a cell

2 ） Supports LTE-> UMTS load-based

handover

Let certain services with a specifics

QCI (such as VoIP) fall back to UMST

3 ） Supports LTE-> UMTS CS/PS service

steering ， CS service （ such as CSFB ）is suggested to fall back carriers in R99,

while PS service(such as coverage-base

service) is recommended to fall back to

carriers in HSPA

1 ） Before LTE supports VoIP, Voice service falls back to UMTS via CSFB:

In UMTS connection mode, UE does not support

inter-RAT measurement, then it will adaptively adopt

CSFB without measurement which need configure

blind priorities of neighbour cells of UMTS cells

In case of unspecific UMTS handover function

supported by the network and UEs, only enable the

switch of redirection.

2 ） If VoIP is deployed in LTE not in UMTS, SRVCC

is applied at the edge of LTE network so as to

handover voice service to UMTS CS domain.

3 ） If VoIP is deployed in both LTE and GSM, PSHO is

adopted at the edge of LTE network so as to handover

VoIP service to UMTS network.

Load Control and service steering Voice Solution

Page22


GUL Networking Strategy

Camping priority ： LTE > UMTS >

GSM

1 ） LTE->GU intersystem handover: Current commercial

UEs are not able to support GSM but UMTS intersystem

measurement, therefore, eNodeB only delivers UMTS

measuring to UE. When the quality of UMTS is better

and UE reports event B1, and eNodeB will handover UE

to a UMTS neighbour cell. If there is no UMTS coverage

are and UE does not report event B1, eNodeB will

directly blind redirect UE whose receiving level in the

serving cell is lower than certain threshold(coverage-

based) or sometime later(CSFB) to GSM.

2 ） After UE supporting GSM measuring, via adjusting

GSM parameters(suggest to longer UMTS measuring

time) to ensure UE report B1 MR of UMTS to realize to

handover to UMTS preferentially

3 ） If UE does not support GU measuring, prefer blind

handover to UMTS can be realized via configuration.

空闲态

Connection Mode / Voice Solution

Idle Mode

UMTS can not realize the

continuous coverage, while

operators require to

preferentially interoperate to

UMTS, therefore forming

GUL scenario

Uses the same strategy with

before, so only differences

list here

Page23


Contents






Page24


Target of GSM/UMTS/LTE Interworking

Data service only; Keep service continuity via GSM/UMTS network ; Avoid the impact on the GSM/UMTS network stability;

Voice service introduced; Load based mobility management; Service based mobility

management;

Expanding / Mature Phase

Page25

Initial Phase


Interworking Procedure Components Interworking procedure includes 4 steps: Trigger, Measurement, Decision

and Execution.

Trigger

Measurement

Decision

Execution

Coverage

LoadQoS

Satisfaction

VoicePS Servic

e

…

Redirection

PS Handover

Re-Selection

IDLEUE Make Decision

RRC ConnectedBS Make Decision

CCO/eNACC

CCO: cell change ordereNACC: network assisted cell changeRRC: radio resource control

withMeasure

ment

Blind

Page26


Contents




3.1 Coverage-Based Interoperability Solution

3.2 Load-Based Interoperability Solution

3.3 Voice Service Continuity Solution

3.4 Interoperability Strategy Cases of Operators



Page27


Last RPLMN

HPLMN & EHPLMN

PLMN of “User Controlled PLMN Selector with Access Technology”

PLMN of “Operator Controlled PLMN Selector with Access Technology”

The PLMN of Better Wireless Quality

Other PLMN Base On Wireless Quality

Camping Procedure

Camping

+

Verify if target is forbidden

Common priority is sent to UE in SIB

LTE TDD > LTE FDD > UMTS/TDS > GSM

or LTE TDD > LTE FDD > HRPD > 1x

1, Faster loading up LTE network;2, Less impact to G/U network and

subscribers.

Various UE individual priorities can be

applied to distribute subscribers to specific

networks based on operator policy.

1, SPID-based UE Individual Priority

2, PLMN-based UE Individual Priority

Common Camping Priority

UE Individual Priority

UE

SIM

UE

SIM

RPLMN(registered PLMN) EHPLMN （ Equivalent HPLMN)

Page28


Common Frequency Priority with SIB Broadcasting

SIB 3 SIB 5 SIB 6 SIB 7Serving Frequency Priority

Inter-Frequency Priority

UTRAN Frequency Priority

GERAN Frequency Priority

Serving = 5 FFDD = 4 FUTRAN = 2 FGERAN = 1

SIB 19Serving = 2FGERAN = 1FFDD = 4FTDD = 5

SIB 2 quaterServing = 1FUTRAN = 2FFDD = 4FTDD = 5

SIB 3 SIB 5 SIB 6 SIB 7Serving Frequency Priority

Inter-Frequency Priority

UTRAN Frequency Priority

GERAN Frequency Priority

Serving = 4 FFDD = 5 FUTRAN = 2 FGERAN = 1

TDD

FDD

UTRAN

GERAN

TDD

FDD

UTRAN

GERAN

Common Priority

Page29


SPID-Based UE Individual Priority

eNodeB

S1-MME(SPID)

GERAN Priority 5

TDD Priority 4

FDD Priority 3

UTRAN Priority 2

TDD Priority 5

FDD Priority 4

UTRAN Priority 3

GERAN Priority 2

Voice packageMobile Terminal

HSS

S6a(SPID)

TDD Priority 5

FDD Priority 4

UTRAN Priority 3

GERAN Priority 2

CPE

SPID

Voice packageMobile Terminal

Data packageMobile Terminal

CPE

UE with Data package (i.e. SPID =10):

The common priority in SIB will work, UE will prefer camping on LTE TDD

UE with voice package(i.e. SPID=20):

eNodeB will send UE individual priority with GSM higher than LTE in RRC Connection Release message.

The individual cell reselection priority will overwrite common priority.

UE will prefer camping on GSM

CPE (i.e. SPID=30), the eNodeB will not send UE individual priority to UE, the common priority in SIB will work, then CPE will prefer camping on LTE TDD

RRC Con

nect

ion

Relea

se

Sys

tem

Info

rmat

ion

Blo

ck

Strategy

System Information Block

HSS

MME

SPID Service Profile Identifier

Cell reselection Info

Cell reselection Info

Cell reselection InfoHSS set SPID info for each subscriber, and send to eNodeB via MME

Data packageMobile Terminal

Page30


PLMN1 PLMN2

RRC Connection Release

FDD Priority 5

TDD Priority 4

UMTS Priority 3

GSM Priority 2


TDD Priority 5

FDD Priority 4

UMTS Priority 3

GSM Priority 2

LTE TDD

LTE FDD

According to the PLMN which UE is registered to, the eNodeB may send individual priority with RAT1 (e.g. FDD) higher than RAT 2 (e.g. TDD) in RRC Connection Release message, the individual priority will overwrite common priority, then UE will prefer camping on its Home Network (e.g. FDD).

Priority based on SPID

Priority based on PLMN

Cell Common Priority

High Priority

Low Priority

Concept Policy

HPLMN is PLMN1 HPLMN is PLMN2

UE Individual Priority based on PLMN

Page31


Coverage-Based Re-Selection in IDLE Mode

Inter-frequency (including Inter-RAT)

Serving cell Target cell

Scan by default

Intra-frequency

Target > Threshold

Broadcast

Serving < Threshold1

Scan

High priority

Low priority

Lowpriority

Highpriority

Target > Threshold 2

Re-selection

Serving cell Target cell Serving cell Target cell

* Threshold based on RSRP or RSRQ

Target – Serving > Offset

Broadcast

Common priority sequence and threshold is broadcasted in SIB message, should be the same for the entire network. SIB 3 5 6 broadcasted in LTE, SIB 19 broadcasted in UMTS.

From Low priority to High priorityScan by default

From High priority to Low or Equal priority

• Good quality in serving cell(Level and Quality) ： not to measure neighbour cells

• Bad quality in serving cell(Level or Quality) ： measure neighbour cells

• Measure or not via switch CFG

• Good quality in serving cell(Level and Quality) ： not to measure neighbour cells

• Bad quality in serving cell(Level or Quality) ： measure neighbour cells

• Measure or not via switch CFG

• Always measure neighbour cells

Page32


Coverage-Based Interworking in RRC Connected Mode

Inter-frequency (Intra-RAT)

Serving cell Target cell

A3 :Target – Serving > Offset

HO/Redirection

Intra-frequency

Coverage based PS handover is recommended to enable by default.Blind PSHO or redirection will be used, if Inter-frequency (including inter-RAT) measurement is not supported by UE

Event: A3/A4/A5A4 is recommended

HO/Redirection

Event: B1/B2

HO/Redirection

Serving cell Target cell Serving cell Target cell

Coverage based Interworking is triggered by A2 Event: Trigger:

Measurement:

* Threshold based on RSRP or RSRQ

Inter-frequency (Inter-RAT)

Page33

Serving < Threshold1


PS Handover Execution Procedure

Example: Inter-RAT handover instance: Handover from LTE cell to G/U cell

SGW PGW

MMELTE

eNodeB

G/U/T BTS

BSC/RNC SGSN GGSN

① HO decision: LTE to GU

eNodeB sends HO request

② MME sends relocation to target SGSN

Target GU network establish access connection

③ eNodeB sends HO command to UE

④ MS detected by target GU network

⑥ Release source network resources

⑤ Target network finish relocation.

Context exchange with source PGW

①

②

②

②

③③

④

⑤

⑤

⑤

⑤⑥

⑥

HO Trigger, Measurement and Decision

Page34


eNACC Procedure

Example: Inter-RAT handover instance: eNACC from LTE

cell to GSM cell

SGW PGW

MMELTE

eNodeB

GSM BTS

BSC SGSN GGSN

① UE send target cell measurement to eNodeB. eNodeB makes HO decision

② eNodeB gets target cell info. by RIM procedure

③ eNodeB sends HO command to UE

④ MS detected by target GSM network

⑥ MME release source network resources

⑤ Target network finish relocation.

Context exchange with source PGW

②

②

②③

④

⑤⑤

⑤

⑤

⑥

⑥

①


Page35


Redirection Procedure

Inter-RAT handover instance: Redirection from LTE cell to G/U cell

SGW PGW

MMELTE

eNodeB

G/U BTS

BSC SGSN GGSN

① UE send target cell measurement to eNodeB. eNodeB makes HO decision

② eNodeB send RRC Release message to UE, carrying RedirectedCarrierInfo that specifies the frequency of the target GERAN/UTRAN cell.

③ UE in RRC IDLE state, reselect the GERAN/UTRAN cell with the specified frequency according to redirection information.

eNodeB requests MME release LTE RRC_Connect.

UE initiates an RAU procedure.

②

③

③

③

③

①


Page36


Contents










Page37


Load Balance Scenarios

• Intra-RAT Load balance can be enabled

when LTE has limited coverage and

subscriber.

• Inter-RAT can be enabled when LTE

expanded coverage and has more

subscribers.

Serving cell

Target cell

Offload

Normal

Load status exchange

Highload

Cell load based activities

Less

loaded

Intra-RAT

Threshold

Inter-RAT

Threshold

Overload

Intra-RAT MLB

Inter-RAT MLB

Load Control

PS Handover;

PS Handover;Redirection;

Reject+Redirection;Release+Redirection;For GBR

RB

use

ra

te

Serving Cell Load

Concept

Policy

Page38


Intra-RAT MLB Procedure with X2

LTE TDD eNodeB LTE FDD/TDD

X2

Reply with cell load information

Request neighbor cell load information

Option 1: Choose target cell by Blind HO priority (if blind HO enabled)Option 2: Require UE to scan candidate target cells. Choose target cell on UE report.Option 3: If No UE supports PSHO. Redirection can be applied.

HO Execution

Serving cell load exceeds Intra-RAT MLB threshold

1

2

3

Make target cell candidate list4

Make UE candidate list, based on RB usage and QoS configuration

5

7

LTE UE

Uu

6

Not recommend Intra-RAT MLB w/o X2 for limited performance than X2 based MLB

Page39


Inter-RAT MLB ProcedureRequest neighbor cell load status by RIM(Consider as normal, if status exchange by RIM is not supported)

LTE TDD eNodeB GSM/UMTS

Reply with cell load status by RIM

Option 1: Choose target cell by Blind HO priority (if blind HO enabled)Option 2: Require UE to scan candidate target cells. Choose target cell on UE report.Option 3: If No UE supports PSHO. Redirection can be applied.

HO Execution

Serving cell load exceeds Inter-RAT MLB threshold

1

3

Make target cell candidate list4

Make UE candidate list, based on RB usage and QoS configuration5

7

Multi-Mode UE

Uu

26

MME

SGSN

Lu-ps

S1 MME

S3/Gn

Page40


Inter-RAT Load Sharing via Redirection in IDLE Mode

UE

TDD sends Individual Priority to UE during Idle Enter Procedures

UMTS Priority 5

TDD Priority 4

FDD Priority 3


Serving cell

Status Unknown

eNodeB send RRC Release message to UE (which is inactive for 20s), carrying RedirectedCarrierInfo that specifies the frequency of the target cell.T320 timer will work. Specified priority will be effective until T320 expires. (T320 will expire when UE service is active and finished.)

UE redirected to target based on the specified frequency in redirection message.UE performs network entry.

?

Target cell

UE RRC Connected which has no traffic will be released to IDLE Mode.

1

2

3

LTE TDD eNodeB GSM/UMTSMulti-Mode UE

• This solution doesn’t impact UE experience.• UE doesn’t support PSHO can be offload to G/U with this scheme.

Page41


Load-Control-Based Redirection(GBR Service)

UE

TDD sends Individual Priority to UE during Idle Enter Procedures

TDD Priority 5

FDD Priority 4

UMTS Priority 3

GSM Priority 2


Serving cell

Overloaded

Status Unknown

eNodeB send RRC Release message to UE, carrying RedirectedCarrierInfo that specifies the frequency of the target cell. UE redirected to target

based on the specified frequency in redirection message.UE performs network entry.

?

Target cell

Either UE in RRC Connected mode or UE attempting to enter.Based on UE priority.

Either Inter-RAT redirection or Intra-RAT redirection when UE doesn’t support PSHO.

1

23

LTE TDD eNodeB GSM/UMTSMulti-Mode UE

It is recommended to reduce load through MLB, not load control.

Page42


Contents










Page43


VoLTESRVCCCS Fall Back

Voice Service Continuity Solution

EPC CS Core

LTEG/U/C

SGs

Call

CS VoicePaging

EPC CS Core

LTEG/U/C

Sv

Call

VoLTE CS Voice

IMS

Access Transfer

Handover

Access

EPC PS Core

LTEG/U/C

S3/S4

Call

VoLTE PS Voice

IMS

Handover

SRVCC: Single Radio Voice Call Continuity

• 2010Q4, world’s 1st LTE to UMTS/GSM CSFB call.

• Jan. 2011, world’s 1st CSFB call with commercial smart phone.

• Apr. 2012, 11 commercial CSFB networks.

Dual-Standby

EPC PS Core

LTE

G/U/C

Call

LTE Data Voice / PS Data

IMS

No Handover

• 2013, CMCC Commercial

Leverage CS Voice Legacy and Introduce IMS PS Voice Service Progressively

• May. 2011, world’s 1st VoLTE call.• Feb. 2012, joint VoLTE demo with

VDF in MWC 2012.

Page44


CS Fall Back Solution for Voice

Voice falls back to G/U/C

LTE G/U/T/C

In the overlapped coverage of LTE and G/U/T/C…

• Reuse G/U/T/C Core;

•No additional core equipment

Provide voice service through G/U/C

network. Two options for the PS data service:

Service handover to G/U/T PS service; Service suspended until voice call is over,

then continue in LTE network.

(Suspending is enabled in CL PS now).

Enable Voice service quickly and

minimize new investment.

Principle Advantage

Page45


Architecture and Functionalities of NE for CSFB

SGW PGW

MME

HSS

PCRF

LTEeNodeB

G/UBTS

BSC/ RNC

SGSN

S1u

S1-MME

S5

Gx

S11

S6a

Gn

MSC/ VLR

Gs• Multi-mode G/U/L;• CSFB capability;

•Paging to UE for CS domain.

• Indicate UE to the target CS cell.

•Above 3GPP R8•SGs/ISUP Connection with MME or SGs Proxy

Mobility management and paging procedures between EPS and CS domain.

SGs

•Mirroring VLR number and LAI with TAI.

•SGs connection for EPS/IMSI Attached UE

•Paging to eNodeB & UE

Gn

Gr

Page46


Fast Return From G/U to LTE

At the End of A Voice

Call

Solution1:Adjust IDLE

Timer

Solution2:NodeB Force UE Return to

LTE

No PS service

With PS service:Wait until

service stops

If there is LTE

With or without PS

service

UE reselect to LTE Frequency

There is NO LTE

UE stay IDLE in UMTS

NodeB redirect / PSHO UE to LTERRC Connected

If there is LTE

NodeB should not initiate redirection or PSHO

Less impact to NodeB and EPC

Need NodeB and EPC support redirection or PSHO

There are 2 ways to determine if there is LTE coverage: (RRC connected)1, Need UE support IRAT measurement. NodeB request UE measures LTE neighbor before PSHO or redirection.2, Only enable Solution 2 on NodeB when there is LTE in same area

There is NO LTE

Page47


Fast Return to LTE at the End of CSFB

Direct access

Without fast return

With fast return

PS Ready

CS callcell

reselection

PS Ready

CS call

PS

PS

Back to LTE after CS call

LTE

GSM/UMTS

GSM/UMTS

LTE

Enter IDLE and Reselect to LTE

Description• At the end of a CSFB call in GSM/UMTS network, the frequency information of LTE cell is sent in RRC Connection

Release message in order to instruct the UE to camp on the LTE cell instead of cell re-selection to LTE.

Benefits• This feature accelerate the camping back to LTE after voice call release and reduce unreachable time of LTE user

• Avoid the impact to non-CSFB user(e.g. UE may be out of network when trying to access LTE for about 10 seconds)

LTE

G/U

Release call with CSFB indication

frequency info.

CSFB

CSFB

BSC/RNC

Page48


SRVCC Solution for Voice

LTE

GSM/UMTSSRVCC to GUT

LTE

GU

Introduce IMS solution; PCC structure, future oriented

Convergent solution;

Provide VoLTE service for LTE

subscribers via IMS; SRVCC for VoLTE to G/U CS call via

handover procedure;

When UE moving from

LTE coverage to GSM/UMTS

with voice service…

Requires IMS and EMSC deployment

Principle Advantage

Page49


SRVCC: Architecture and Functionalities of NE

SGW PGW

MME

HSS

PCRF

LTEeNodeB

BSC/ RNC

SGSN

S1u

S1-MME

S5

Gx

S11

S6aS3S12

S4

MSC/ VLR/IWF

GsSv

•Enhanced MSC (with IWF)•SRVCC capability•Relocation procedure to CS.• Invoking session transfer procedure, voice continuity through SCC AS.

•Coordinating CS handover and session transfer.

• Indication to MME about SRVCC•Determine the neighbor cell supports SRVCC \

• PS bearer splitting voice bearer (QCI=1) from the non-voice bearer

• Handling the non-voice HO to target cell• Initiating SRVCC of the IMS voice call to the 2G/3G cell via Sv

•Multi-mode G/U/L UE• IMS/SRVCC capability

IMS

SGi

Rx

G/U BTS

Page50


eSRVCC Solution

eSRVCC (R10)SRVCC (R8)

• Re-establish the call signaling and bearer end to end.

• IMS session transfer for remote end has uncertain interruption, especially for: long service handling durationmultiple nodes involvedcomplex service logic and triggeringroaming out of home network

•Remote end update is avoided to reduce the interruption significantly (equal to HO interruption of radio access, usually < 300ms).

G/U CS

MSC

EPC

IMS

CS Voice

LTE PS SBC

PS Voice

G/U CS

MSC

EPC

IMS

CS Voice

LTE PS SBC

PS Voice ATGWATGW

ATCFATCF

signaling before HObearer before HO

signaling after HObearer after HO

Page51


Contents










Page52


Interworking Strategy of Operator S

1.5G UMTS (Data)Ericsson

2.1G UMTS (Voice/Data)Ericsson

Voice CSFB(Based on voice service)

Redirection(Based on

coverage.PS handover will be

enabled when terminal is available)

Offload(Default camping on

LTE TDD. Reselect to LTE TDD when UE is under LTE coverage. Redirection or PSHO will be enabled when UMTS is able to be upgraded)

LTE TDD 2.6GHuawei

Reselection/Fast Return(As soon as

voice service is finished and UE under LTE coverage)

Page53


Interworking Strategy of Operator B

900M/2.1G UMTS (Data)Huawei, XXX(aother operator)

Voice CSFBTo G/U(Based on

voice service)

Redirection(Based on coverage.PS handover will be

enabled when terminal is available)

LTE FDD 1.8G/2.6GHuawei

900M/1.8G GSM (Voice)huawei

LTE TDD 2.3GLoad Balance

Offload to LTE(Default camping on LTE TDD. Reselect to LTE TDD when UE is under LTE coverage. Redirection or PSHO will be enabled when UMTS is able to be upgraded)

Reselection(As soon as

voice service is finished and UE under LTE coverage)

Page54


Interworking Strategy of Operator C

TDS-CDMA

GSM

LTE TDD 2.6G

Default Camping

GL Reselection

TL Reselection

TL Redirection

GL Redirection

CCO/ eNACC

Voice CSFBTo G/T(SRVCC in

future)

Fast Return（ rSRVCC in future ）

Page55


Country / region

Operator GU Vendor EPCInterworki

ng Voice PS

Network Structure

Japan SBMEricsson G/U

HuaweiCoverage-based

CSFB

Reselection between LTE and UMTSRedirection from LTE to UMTS

Gn/Gp

Hong Kong

GB(PCCW/Hutchison)

Huawei G/UNSN UHuawei LTE FDD/TDD


CSFB(EMSC) to G/U(blind redirection)


Gn/Gp

Saudi STC Ericsson , Huawei, NSN G/U


CSFB Redirection Gn/Gp

China CMCCHuawei TDS

Gn/Gp

SA TelkomHuawei G/U

Huawei Gn/Gp

Sweden Net4M UMTS NSNCoverage- based

CSFB to UMTS(blind redirection)


Gn/Gp

Interworking Cases(1)

Page56


Interworking Cases(2)Country /

regionOperator

GU Vendor

EPCInterworkin

g Voice PS

Network Structure

Canada Bell/TelusHuawei UTMS

CISCOCoverage- based



Gn/Gp

Singapore M1Huawei GU

Huawei

Coverage- basedLoad- based

CSFB

Reselection between LTE and UMTSPSHO from LTE to UMTS

Gn/Gp

Germany VDF D2 NSN UMTS NSN Coverage-

based

CSFB to GSM(blind redirection)

Reselection among LTE UMTS GSMRedirection from LTE to UMTS or GSM

Gn/Gp

Japan eAccess Huawei GU Ericsson

Coverage-basedLoad- based

CSFB to UMTS(blind redirection or PSHO)

Reselection among LTE UMTS GSMRedirection from LTE to UMTS or GSM

Gn/Gp

Page57


Interworking Cases(3)Country /

regionOperator

GU Vendor

EPCInterworki

ng Voice PS

Network Strucuture

Norway Telenor Huawei umts Cisco Coverage

-based



Gn/Gp

Norway Netcom Huawei GU Huawei Coverage

-based



Gn/Gp

Kuwait Zain Huawei Huawei Gn/Gp

UAE Etsalat Huawei huawei Coverage-based


Gn/Gp

Saudi Zain Huawei Huawei Gn/Gp

UAE DU huawei Cisco Coverage-based


Gn/Gp

Page58


Contents






Page59


KPI Related to Interoperability(1/2)

Counter ID Counter Name Counter Description

1526726989 L.IRATHO.E2W.PrepAttOutNumber of Outgoing Handover Attempts from E-UTRAN to UTRAN

1526726990 L.IRATHO.E2W.ExecAttOutNumber of Performed Outgoing Handovers from E-UTRAN to UTRAN

1526726991 L.IRATHO.E2W.ExecSuccOutNumber of Successful Outgoing Handovers from E-UTRAN to UTRAN

1526726992 L.IRATHO.E2G.PrepAttOutNumber of Outgoing Handover Attempts from E-UTRAN to GERAN

1526726993 L.IRATHO.E2G.ExecAttOutNumber of Performed Outgoing Handovers from E-UTRAN to GERAN

1526726994 L.IRATHO.E2G.ExecSuccOutNumber of Successful Outgoing Handovers from E-UTRAN to GERAN

Page60


KPI Related to Interoperability(2/2)

LTE->WCDMA %100Out2W.ExecAttL.IRATHO.E

cOut 2W.ExecSucL.IRATHO.E_2_ outSRWEIRATHO

LTE->GSM %100Out2G.ExecAttL.IRATHO.E

cOut2G.ExecSucL.IRATHO.E_2_ outSRGEIRATHO

Page61


Traffic Statistics(1/2)Counter ID Counter Name Counter Description

1526728326 L.RRCRedirection.E2W Number of Redirction to WCDMA

1526728330 L.RRCRedirection.E2W.PrepAtt Number of attempt Redirction to WCDMA

1526728327 L.RRCRedirection.E2G Number of Redirction to GERAN

1526728331 L.RRCRedirection.E2G.PrepAtt Number of attempt Redirection to GERAN


1526728321 L.CSFB.PrepAtt Number of CS fallback indicators received by the eNodeB

1526728322 L.CSFB.PrepSucc Number of successful CS fallback responses from the eNodeB

1526728323 L.CSFB.E2W Number of CS fallback procedures to UTRAN

1526728324 L.CSFB.E2G Number of CS fallback procedures to GERAN

Redirection

CSFB

Page62


Traffic Statistics(2/2) Reasons of handover failure:


1526728316 L.IRATHO.E2W.Prep.FailOut.MMENumber of handover prepare failure from LTE to WCDMA for MME reason

1526728317 L.IRATHO.E2W.Prep.FailOut.PrepFailureNumber of handover prepare failure from LTE to WCDMA for prepare failure indication from WCDMA

1526728318 L.IRATHO.E2C.Prep.FailOut.NoReplyNumber of handover prepare failure from LTE to WCDMA for no reply with WCDMA

1526728306 L.IRATHO.E2G.Prep.FailOut.MMENumber of handover prepare failure from LTE to GERAN for MME reason

1526728307 L.IRATHO.E2G.Prep.FailOut.NoReplyNumber of handover prepare failure from LTE to GERAN for no reply with GERAN

1526728308 L.IRATHO.E2G.Prep.FailOut.PrepFailureNumber of handover prepare failure from LTE to GERAN for prepare failure indication from GERAN

Page63


Drive Test Index

Via Assistant-based tool

Page64


Contents






Page65


Huawei Leading CSFB Commercialization

Nov. 2010 Dec. 2010 Jan. 2011 Oct. 2012

Huawei made World’s 1st LTE to UMTS CSFB Call

Huawei made World’s 1st LTE to GSM CSFB Call

World’s 1st CSFB Call with Commercial Smartphone

World’s 1st LTE TDD CSFB with Commercial SmartPhone

Oct. 2012

11 Commercial CSFB Networks

See the red star

Page66


Huawei LTE IOT Status (Main Terminals)

Module Vendor Chipset Type RAT

E398(1st LTE FDD/TDD USB Dongle)

Huawei Hisilicon Balong 700 USB Dongle LTE(FDD/TDD)

E392u(1st GUL(F/T) USB Dongle)

Huawei Qualcomm MDM 9200 USB Dongle GUL(FDD/TDD)

E589u(1st GUL(F/T) mobile wifi)

Huawei Qualcomm MDM 9200 USB Dongle GUL(FDD/TDD)

B593(1st GUL(F/T) CPE) Huawei Hisilicon Balong 700 CPE GUL(FDD/TDD)

B222s(1st outdoor CPE) Huawei Altair FG3100 CPE LTE(TDD)

9201L(1st GULSmartPhone)(Chipset F/T Ready)

Huawei Qualcomm MSM 8960 Smartphone GUL(FDD/TDD)

E5776 Huawei Hisilicon Balong 710 Mobile WiFi GUL(FDD/TDD)

E3276 Huawei Hisilicon Balong 710 USB Dongle GUL(FDD/TDD)

Page67


Huawei LTE IOT Status (Main Chipsets)

Module Vendor 3GPP version Cat RAT

MDM 9200 Qualcomm R8 Cat 3 GUCL

MDM9600 Qualcomm R8 Cat 3 GUCL

MSM 8960 Qualcomm R9 Cat 3 GUTCL

MDM 9X15 Qualcomm R9 Cat 3 GUTCL

XMM7060 Intel R8 Cat 3 GUL

Balong 700 Hisilicon R8 Cat3 LTE

Balong 710 Hisilicon R9 Cat 4 GUL

FG3100 Altair R9 Cat 4 GUL

LC1760 LeadCore R8 Cat 3 TDS-CDMA, LTE TDD

SQN3010 Sequans R8 Cat 3 LTE

Page68


Mainstream Chipset Capabilities

3GPP R9 LTE TDD/FDD/TDS-CDMA/UMTS/GSMCSFB/SRVCC(2013Q1)Redirection, PSHOIRAT Measurement

3GPP R9 LTE TDD/FDD/HSPA+/GSMCSFB,Redirection, PSHO, IRAT Measurement

Balong 710Snapdragon MSM 8960

Page69


Summary

Incentive of Interoperability

Structure Key Interface of Interoperability

Deployment Strategy of Interoperability

Networking Strategy of Interoperability

Procedure of Interoperability

Coverage-based/Load-based Solution of of

Interoperability

KPI Related of Interoperability

Cases of Interoperability

Page70


GU Matching Version List

Target

SystemCapacity of Target RAN

The Lowest

Version

The Version

Suggested

GSM

GSM->LTE Cell Reselection GBSS12.0 GBSS14.0

LTE->GSM PSHO GBSS12.0 GBSS14.0

LTE->GSM CCO/NACC GBSS12.0 GBSS14.0

LTE->GSM SRVCC GBSS12.0 GBSS14.0

UMTS

UMTS->LTE Cell Reselection RAN 12 RAN 14

LTE->UMTS PSHO RAN 13 RAN 14

LTE->UMTS SRVCC RAN 15Not published

yet

Thank youwww.huawei.com

Documents

GUL Interoperability Overview