11 2_g-3g_handover

2G to 3G Handover NE B9MR4 Seminar- Cairo, May’07

2 | Presentation Title | Month 2006 All Rights Reserved © Alcatel-Lucent 2006, #####

Agenda

1. Introduction2. Detailed description3. Parameters4. PM Counters and QoS indicators


Introduction


Introduction

Improvement in B9 in term of 2G<->3G Interoperability comes from� 2G to 3G Handover� Load based 3G Ho Filtering� Improved 3G cell reselection2G to 3G Handover In B9 MR4� In B8 and B7 only 3G to 2G handover are handled by the BSS� The only way for a UE/MS to return to UMTS is by idle mode reselection� Starting B9 MR4 handover towards UTRAN (FDD) is supported by

threshold triggering on Ec/No (R’99 compliant UE/MS)� TCH/2G to TCH/3G handover only � The MSC may inform the BSS if perference for specific radio access

technology shall be applied

2G2G2GCS call 3G camping3G 3G campingcampingHandover

2G2G2G 3G3G3G


Introduction

� Cause31 is activated by setting EN_3G_HO equal to yes


Detailed Description


Detailed Description – Classmark handling

� A UE/MS send (UTRAN) CLASSMARK CHANGE message to inform the network about its INTER RAT HANDOVER INFO (3GPP 25.331)

� The BSC stores this information for further possible 2G-3G HO� The BSC instructs the UE/MS to send UTRAN CLASSMARK CHANGE message if

it’s able to do so.� In case of intersystem HO, HANDOVER REQUIRED message contains “source

RNC to target RNC transparent information” which contains

� Inter RAT HO Info (Multiple/Single UTRA FDD frequency bands, Measurement capabilities,…etc)


Detailed Description - System Information

Objective� Informs the MS of the BSS capabilities, and that it supports early classmarksending procedure (sent on BCCH)� Provides the MS with necessary information to perform measurements� Provides the MS with Cell Distribution list which contains list of shared SYSINFO between all the MS in the serving cell (sent on BCCH)� Provides the MS with Cell Non-Distribution list which contains individual UE dedicated SYSINFO (sent on SACCH or PACCH/PCCCH)� Example of shared SYSINFO

– GSM Neighbor list for reselection– Measurement report type

� Example of dedicated SYSINFO– 3G Neighbor list is distributed to Inter-RAT enabled UE/MS– Measurement reporting thresholds and offset– Qsearch_C instructs the mobile, when It should search for 3G neighbors. This depends on 2G received level (default is below -70 dBm, i.e. always search for 3G cells)– FDD_MULTIRAT_REPORTING Number of the strongest 3G cells to be reported by the MS in the measurement report message (default is 2)


Detailed Description - System Information

Message exchange

2G/3G_Neighbour_cell list used for cell

reselection

2G/3G_Neighbour_cell list used for Handover. Note:

3G_Neighbour_Cell(SACCH) is limited to 32 compliant with

3GPP

REPORTING_THRESHOLD , REPORTING_OFFSITAnd

Qsearch_C


� CGI_3G_REQD: Controls format of 3G cell identification towards the MSC (depends on MSC type).

� If CGI_3G_REQD = 1 then 3G cell will be identified on A interface with Cell global IdentifierElse with Partial Identifier

Detailed Description - Cell References and building neighbor cell lists

Cell Reference How we identify 3G cells (analogy to 2G)?

Local Cell IdentifierO&M cell identifier

UC-ID = RNC-ID + C-ID, C-IDLAC + CI, CIPartial identifiers

MCC + MNC + RNC-ID + C-IDCGI = MCC + MNC +LAC + CICell Global Identifier

Only UARFCN or (UARFCN + Scrambling codes per scrambling code group)

Only ARFCNPartial radio reference

UARFCN + Primary scrambling codeARFCN + BSICComplete radio reference

3G cells2G cells



Building GSM neighbor cell list

≤ 32 ARFCN

≤ 96 (ARFCN + BSIC)

Built from the BA(SACCH) (SI5, SI5BIS, SI5TER) and the BSIC description given in one or more instances of the MEASUREMENT INFORMATION message

SACCH/DLGSM_Neighbour_Cell(SACCH)

Built from the BA(GPRS) defined in PSI3 message and PSI3BIS message on PBCCH.

PBCCH/DLGSM_Neighbour_Cell(PBCCH)

≤ 96 (ARFCN + BSIC)and SI2QUATER

≤ 32 ARFCNBuilt from BA(BCCH) (SI2, SI2BIS, SI2TER messages)

BCCH/DLGSM_Neighbour_Cell(BCCH)

Max lengthInputs used by the UE/MS to build the neighbour cell list

Logical channel

GSM Neighbour cell list



Building UMTS neighbor cell list

64One or more instances of the MEASUREMENT INFORMATION message

SACCH/DL3G_Neighbour_Cell(SACCH)

64Built from 3G neighbor cells defined in PSI3QUATER message

PBCCH/DL3G_Neighbour_Cell(PBCCH)

64SI2TER or SI2QUATER messagesBCCH/DL3G_Neighbour_Cell(BCCH)

Max lengthInputs used by the UE/MS to build the neighbour cell list

Logical channel

Neighbour cell list



Neighbor cell list

scrambling code(m/k)UARFCN(k)n

.........

scrambling code(1/1)UARFCN(1)

BSIC(j)ARFCN(i)

.........

BSIC(2)2

BSIC(1)ARFCN(1)1

BSIC/scrambling code

ARFCN/UARFCNIndex


Detailed Description – Measurement Processing

� CPICH Ec/No (3GPP TS 25.215): The received energy per chip divided by the power density in the band. Measurement shall be performed on the Primary CPICH. The reference point for the CPICH Ec/No shall be the antenna connector of the UE.

� If Tx diversity is applied on the Primary CPICH the received energy per chip (Ec) from each antenna shall be separately measured and summed together in Ws to a total received chip energy per chip on the Primary CPICH, before calculating the Ec/No.

� EN_3G_DIVERSITY(n) indicates if diversity is applied in the 3G cell


Detailed Description – Measurement Processing

� For 3G cells, as the 2G to 3G handover doesn’t take care of 3G cell load. We should take into account only the better 3G cells

� The MS can include a 3G cell in the measurement report if:CIPCH Ec/No + FDD_REPORTING_OFFSET >= FDD_REPORTING_THRESHOLD

(default offset=0dBm and default threshold =0, i.e. always report the measurment)� Measured Ec/No on FDD UTRAN is the average of the measured samples taken

over the reporting period which is the duration of one SACCH (480 ms)� The reported Ec/No on UTRAN FDD neighbor cells are averaged using a slide

window arithmetic on a given window length (A_ECNO_HO, default=8)


Detailed Description - 2G-3G Handover Preparation� Each time the UE/MS reports measurements the process reevaluates the

Ec/No for all 3G cells measurement reported� For each cell I if AV_ECNO(i) ≥ THR_ECNO, the cell I shall be added in the

list of candidate cells ranked according to AV_ECNO(i) and 3G cells on top of the list

� The 3G cell with highest AV_ECNO(i) is marked as candidate cell for handover


High Level Description - 2G-3G Handover Management

Rejected cell handling is inherited from legacy handover management� Two lists of rejected cells, associated to each connection� MS_CELL_REJ_LIST: A list of cells to which the MS failed to handover guarded by

the timer T_MS_CELL_REJ.� REJ_CELL_LIST: A list of cells to which the handover is temporarily impossible

(e.g. for congestion) . This list is guarded by T7. When T7 expires, this list is emptied. The size of this list is 2*N_PREF_CELLS.

Candidate cell

3G cell, External ChannelChange Process

Included in Ms_cell_Rej_List? And T_MS_CELL_REJ is running

Included in Rej_Cell_List?And T7 is running

HandoverRequired

No

No

Yes

Rejected

Rejected

Yes


High Level Description - 2G-3G HO execution


Parameters


Parameter Setting

3G cellNone-140950This parameter indicates the RNC Identifier as defined in 3GPP TS 25.401. It is used in HO Required message sent to the MSC.RNC_ID(n)

cellNone010This flag enables/disables the 2G-3G handoverEN_3G_HO

3G cellNone9999990Mobile Country Code of a neighbour 3G cell of the own or of a foreign PLMN.MCC_3G(n)

3G cellNone9999990Mobile Network Code of a neighbour 3G cell of the own PLMN or of a foreign PLMN.MNC_3G(n)

celldB0420Offset that the MS shall apply to measurements before reportingFDD_REPORTING_OFFSET

cellNone230Number of the strongest 3G cells to be reported by the MS in the measurement report messageFDD_MULTIRAT_REPORTING

3G cellNone-1655350This parameter indicates the Cell Identifier of a 3G cell as defined in 3GPP TS 25.401CI_3G(n)

cellSamfr8311Window size for Ec/No level averages for 2G to 3G handoverA_ECNO_HO

celldB0420Threshold above which the MS shall report the measurementsFDD_REPORTING_THRESHOLD

3G cellNone-1655350This parameter indicates the Location Area Code as defined in 3GPP TS 24.008.It is used in the HANDOVER COMMAND messageLAC_3G(n)

BSCsec1425,50

This timer is started by sending an INTER SYSTEM TO UTRAN HANDOVER message to the MS andis normally stopped when the MS has correctly seized the UTRAN channel(s).Its purpose is to keep the old channels sufficiently long for the MS to be able to return T3121

celldBm-91-47-110Ec/No threshold above which a handover to UTRAN may be triggeredTHR_ECNO_HO

celldBm-70-50-98Threshold for searching for 3G cells in dedicated mode depending whether the received signallevel of the serving cell is below or above the threshold.Qsearch_C

3G cellNone010This parameter indicates if diversity is applied for the cellEN_3G_DIVERSITY(n)

3G cellMHz-13276.60FDD UTRAN frequencyFDD_ARFCN(n)

3G cellNone-15110This parameter indicates the Primary Scrambling Code as defined in 3GPP TS 25.213SCRAMBLING_CODE_3G(n)

BSCNone110Controls format of 3G cell identifications sent to the MSC.CGI_3G_REQD

InstanceUnitDefMaxMinDefinitionLogical name


PM Counters and QoS indicators


PM Counters and QoS Indicators

Cell1102 bytesNumber of outgoing 2G to 3G handover preparation failures

NB_OUT_2G_3G_HO_PREP_FAILMC924g

Cell1102 bytesNumber of outgoing 2G to 3G handover execution failures with reversion to old channel

NB_OUT_2G_3G_HO_EXEC_FAIL_REVMC924f

Cell1102 bytesNumber of outgoing 2G to 3G handover execution failures without reversion to old channel

NB_OUT_2G_3G_HO_EXEC_FAIL_NO_REVMC924e

Cell1102 bytesNumber of outgoing 2G to 3G handover attemptsNB_OUT_2G_3G_HO_ATPTMC924d

Cell1102 bytesNumber of outgoing 2G to 3G handover successes towards a 3G neighbour cell

NB_OUT_2G_3G_HO_SUCCMC924c

Cell1102 bytesNumber of outgoing 2G to 3G handover requestsNB_OUT_2G_3G_HO_REQMC924b

Cell142 bytesThe average receive Ec/No of a 3G FDD neighboring cell as seen by the Mobile

AV_ECNOHO1103 to HO8103

Cell142 bytesThe UTRAN Absolute Radio Frequency Number of a 3G FDD neighboring cell

FDD_FREQHO1102 to HO8102

Cell142 bytesThe scrambling code of a 3G FDD neighboring cellSCRAMBLING_CODEHO1101 to HO8101

Cell112 bytesThe average receive Ec/No of a 3G FDD neighboring cell as seen by the Mobile

AV_ECNOR120 to R820

Cell112 bytesThe UTRAN Absolute Radio Frequency Number of a 3G FDD neighboring cell

FDD_FREQR119 to R819

Cell112 bytesThe scrambling code of a 3G FDD neighboring cellSCRAMBLING_CODER118 to R818

Measured objectTypeSizeDefinitionMnemonicCounter number


PM Counters and QoS Indicators

number

Number of Outgoing External 2G->3G HO execution failures due to to radio problem (TCH).As the problem is located on the serving cell, the call is dropped. This

includes both inter-PLMN and intra-PLMN events.MC924ecellOUT_MSC_2G_3G_DROP_RADIOHOOMCDRUN

number

Number of Outgoing External 2G->3G HO preparation failures due to congestion (TCH).This includes both inter-PLMN and intra-PLMN events.MC924gcellOUT_MSC_2G_3G_PREP_FAIL_CONGHOOMCGUN

%Rate of Outgoing External 2G->3G HO successes (TCH).This includes both inter-PLMN and intra-PLMN events.

HO_Out_MSC_2G_3G_success / HO_Out_MSC_2G_3G_requiredcellOUT_MSC_2G_3G_SUCCESS_RATEHOOMSUUR

numberNumber of Outgoing External 2G->3G HO successes (TCH).This includes both inter-PLMN and intra-PLMN events.MC924ccellOUT_MSC_2G_3G_SUCCESSHOOMSUUN

numberNumber of Outgoing External 2G->3G HO requests (TCH).This includes both inter-PLMN and intra-PLMN events.MC924dcellOUT_MSC_2G_3G_REQUESTHOOMRQUN

numberNumber of Outgoing External 2G->3G HO required (TCH).This includes both inter-PLMN and intra-PLMN events.MC924bcellOUT_MSC_2G_3G_REQDHOOMRDUN

number

Number of Outgoing External 2G->3G HO execution failures due to radio problem with reversion of the mobile to the old channel (TCH). This includes both inter-PLMN and intra-PLMN events.MC924fcellOUT_MSC_2G_3G_ROCHOOMOCUN

%Rate of Outgoing External 2G->3G HO preparation failure rate (TCH).Thisincludes both inter-PLMN and intra-PLMN events

OUT_MSC_2G_3G_REQUEST/

OUT_MSC_2G_3G_REQDcellOUT_MSC_2G_3G_PREP_FAILURE_RATEHOOMFLPUR

%

Rate of Outgoing External 2G->3G HO successes (TCH) over the outgoing handover requests

This includes both inter-PLMN and intra-PLMN events.HO_Out_MSC_2G_3G_success /

HO_Out_MSC_2G_3G_requestcellOUT_MSC_2G_3G_EFFICIENCY_RATEHOOMEFUR

Number

Number of Outgoing External 2G->3G HO execution failures due to BSS problems (transmission,... ) and radio problem (TCH). As the problem is located on the serving cell, the call is dropped. This includes both inter-PLMN and intra-PLMN events

HO_Out_MSC_2G_3G_drop_BSS + HO_Out_MSC_2G_3G_drop_radiocellOUT_MSC_2G_3G_DROPHOOMCDUN

number

Number of Outgoing External 2G->3G HO execution failures due to BSS problems (transmission,... ) (TCH). As the problem is located on the serving cell, the call is dropped. This includes both inter-PLMN and intra-PLMN events

HO_Out_MSC_2G_3G_request -HO_Out_MSC_2G_3G_success -HO_Out_MSC_2G_3G_drop_radio -HO_Out_MSC_2G_3G_ROCCellOUT_MSC_2G_3G_DROP_BSS_PROBLEMHOOMCDBUN

UnitDescriptionFormulaObjMnemonicRefName


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11 2_g-3g_handover

Technology

g cell reselection

g cell identification

g neighbor list

g neighbors

g neighbor cells

g handover load

g cells fdd

cell distribution list