9b-kts l103792 sib5 inter-freq reviewed

103792 Intra-LTE Inter-freq Mobility

Intra-LTE Inter-freq /iRAT MobilityReselection part

Antoine GUIRAUDMay, 2011

• Intra-LTE Inter-freq Mobility: Reselection part

• i-RAT HRPD Mobility: Reselection part

AGENDA

COPYRIGHT © 2011 ALCATEL-LUCENT. ALL RIGHTS RESERVED.

ALCATEL-LUCENT — CONFIDENTIAL — SOLELY FOR AUTHORIZED PERSONS HAVING A NEED TO KNOW — PROPRIETARY — USE PURSUANT TO COMPANY INSTRUCTION

4


Intra-LTE Inter-freq Mobility Reselection part (FRS 103792)



5

• Feature flag

• ActivationService :: isInterFreqEutraSameFrameStructureMobilityAllowed

• This parameter enables or disables both:

1. inter-freq cell reselection

2. Handover

3. Redirection.

Note: this flag is not used for target eNB to check incoming handover in LA3.0.

Activation



6

SIB Management

• SIB: Overall functional parameters useful for specific feature and send together via DL-SCH channel

• If SIB2/SIB3 cannot be built, it means the cell is not available and that cell state is set to disabled/failed. The ENB raises a critical alarm (need operator intervention).

• If SIB4 or SIB5 cannot be built, the only consequence is that it is not broadcasted. But feature is not implemented.

From Mandatory SIB Optional SIB To

LTE SIB1-SIB2-SIB3 SIB4 LTE-Intra-Freq

LTESIB1-SIB2-SIB3

SIB5SIB4 LTE-Inter-Freq

LTESIB1-SIB2-SIB3

SIB6WCDMA

LTESIB1-SIB2-SIB3

SIB7GERAN

LTESIB1-SIB2-SIB3

SIB8HRPD

Mobility types



7

One of the main parameter : Qrxlevmin

• This parameter configures the cell min required RSRP level used by the UE in cell reselection.

Intra FreqTarget CellPCI#3

WCDMATarget CellCell#9

GERANTarget CellCell#12

CDMATarget CellCell#15

Inter FreqTarget CellPCI#6

CellReselectionConfLte::qrxlevminin SIB5

CellReselectionConfLte::qrxlevminin SIB3

CellSelectionReselectionConf::qrxlevminin SIB1

CellReselectionConfUtraFdd or Tdd::qrxlevminin SIB6

CellReselectionConfGERAN::qrxlevminin SIB7

Snonservingcell = -FLOOR (-20 x log10Ec/Io) in

SIB8 (No qrxlevmin)

SourceCellPCI#1



8

MIM Structure

SIB5 parameters

Activation flag

SpeedStateEvalConf

(Optional)

• nCellChangeHigh

• nCellChangeMedium

• tEvaluation

• tHystNormal



9

Cell Reselection priority

LTE to EUTRAN-EUTRAN inter freq Cell reselection priority is configurable.

In ALU generic configuration LTE cells priority is set as:

CellReselectionConfLte::cellReselectionPriority = 5 (SIB3 and SIB5)

Note :

Be careful, in LA2.0 this parameter was located under cellSelectionReselectionConf MO + cellreselectionconfinterfreq ……



10

LTE to LTE inter freq Mobility – Cell Reselection RAT

priority – LA5 – LA6• LTE to LTE inter freq Cell reselection priority is configurable.

• In the context of the LTE network trial introduction, we assume the number of UE having both 3G and LTE capability to be low.

• The ALU generic configuration is:

1. LTE cells have highest priority

CellReselectionConfLte::cellReselectionPriority = 5 (SIB3)

2. Other LTE cell with higher, lower or same priority than LTE

[Auther instance of LteNeighboringFreqConf than LTE cell]




3. UTRAN & GERAN cells have the lowest priority

CellReselectionConfUtraFdd: cellReselectionPriority = 3 (SIB6)



11

Reselection Measurements management UE R8• In order to limit the amount of inter-freq measurements an additional criteria broadcasted in

SIB3 is used:

• CellSelectionReselectionConf::sNonIntraSearch : threshold for serving cell reception under which

the UE may trigger inter-freq and inter-RAT measurements for cell reselection.

• The UE applies rules as follows, where CRP = Cell Reselection Priority and IFREQ=inter freq target cell, S

= selection criterion:

CRP-ifreq ≥ CRP-servingcell?

Is S-nonintrasearch sent in SIB3?

Is S-servingcell > S-nonintrasearch?UE may choose not to perform

measurements of inter frequency cells of equal or less priority.

•YES

NO

YES

NO

NO

YES

UE performs measurements of the equalpriority inter-frequency

=

> UE performs measurements of the higherpriority inter-frequency

UE performs measurements of Inter-frequency cells of lower CRP.



12

LTE to LTEinterFreq/ inter-RAT Mobility – Cell Reselection Priority

Algorithm Overview - UE R9

• In order to limit the amount of inter-RAT measurements an additional criteria broadcasted in SIB3 is used:

• sNonIntraSearchP and sNonIntraSearchQ: thresholds for serving cell reception under which the UE may trigger

inter-RAT or/and inter-Freq measurements for cell reselection.

• Configurable under : CellSelectionReselectionConf::sNonIntraSearchP / sNonIntraSearchQ

• The UE applies rules as follows, where CRP = Cell Reselection Priority and IRAT=UTRAN, GERAN interFREQ EUTRAN , S

= selection criterion:

CRP-irat > CRP-servingcell?

Is sNonIntraSearchP or

sNonIntraSearchQ sent in SIB3?

Is S-rxlev > sNonIntraSearchP

And S-qual > sNonIntraSearchQ?

UE performs measurements of IRAT

frequency cells of higher (equal*) or lower

CRP.

UE performs measurements of the

higher priority inter-RAT frequency.

UE may choose not to perform

measurements of inter-RAT frequency

cells of (equal*) or less priority.

•YES

NO

YES

NO

NO

YES

* Equal priority in restriction in LA3 and LA4 for iRAT.



13

INTER-FREQUENCY CELL SELECTION CRITERION - UE R9

• For UE R9 capable:

If Srxlev > sNonIntraSearchP and Squal > sNonIntraSearchQthen the UE will

• search for inter-frequency layers of higher priority at least every

• Thigher_priority_search

If Srxlev ≤ sNonIntraSearchP or Squal ≤ sNonIntraSearchQ then the UE shall

• search for and measure inter-frequency layers of higher, equal or lower priority in

• preparation for possible reselection.

• The UE will measure RSRP or RSRQ at least every Kcarrier * Tmeasure,EUTRAN_Inter for identified lower or equal priority interfrequency cells.



14

Measurement Configuration for inter freq reselection: Cell selection criterion for inter-freq reselection UE R8

• Almost the same as intra-freq criterion except : Pmax parameter which is optional (Sent in SIB1).

• The UE decides the best candidates for cell reselection by calculating an ‘S’ criterion for each

broadcasting cell. The ‘S’ criterion of a cell is fulfilled when:

Srxlev [= Qrxlevmeas – (Qrxlevmin + Qrxlevminoffset) – Pcompensation] > 0

Where: Pcompensation= Max [Pmax- Pumax, 0]

Pumax=23 dBm for UE class3 (currently only class3 are available)

To see LPUG Volume 6 section 4.1.3.1 table2 for more information on UE classes

• Qrxlevmin is a tunable parameter sent in SIB5 (inter-freq specific)

• Qrxlevminoffset a tunable parameter sent in SIB1 (used if search for higher priority PLMN)

Note: For an E-UTRAN cell, the measured RSRP value shall be greater than or equal to -110 dBm



15

� The UE decides the best candidates for cell reselection by calculating an ‘S’ criterion for each broadcasting cell. The ‘S’ criterion of a cell is fulfilled when:

Srxlev [= Qrxlevmeas – (Qrxlevmin + Qrxlevminoffset) – Pcompensation] > 0

• Where : Pcompensation= Max [pMax- Pumax, 0]

• CellSelectionReselectionConf::pMax is a tunable parameter sent in SIB1 (LTE),

• CellReselectionConfLte::pMax is a tunable parameter sent in SIB3&SIB5 (LTE),

• Qrxlevmin is a tunable parameter sent in SIB6 (UMTS) , SIB7 (GERAN), SIB3&SIB5 (LTE)

• Qrxlevminoffset a tunable parameter sent in SIB1 (used if search for higher priority PLMN)

� Additional criterion for UMTS and LTE cell reselection :

Squal [= Qqualmeas – (Qqualmin + Qqualminoffset)] > 0

• Qqualmeas is measured by the UE

• Qqualmin is a parameter sent in SIB6 (CellReselectionConfUtraFdd) or SIB3&SIB5

(CellReselectionConfLte)

• Qqualminoffset is not implemented in LA3 but is implemented in LA4

LTE to LTE and LTE to UTRAN/GERAN Mobility – Cell Reselection Evaluation UE R9

• Red = NEW IN LA4.0



16

Measurement Configuration for inter-freq reselection :

Prerequisite

• If the S-ServingCell of the E-UTRA serving cell (or other cells on the same frequency layer) is greater than sNonIntraSearch then (3GPP 36.133):

• the UE may not search for, or measure inter-RAT or inter-freq layers of lower or equal priority.

• the UE search for inter-RAT or inter-freq layers of higher priority at least every higher_priority_search= (60 * Nlayers) seconds, where Nlayers is the total number of configured higher priority E-UTRA, UTRA FDD, UTRA TDD, CDMA2000 1x and HRPD carrier frequencies and is additionally increased by one if one or more groups of GSM frequencies is configured as a higher priority.

•t

RSRP

S-ServingCell

Min. = (60* Nlayers) s.

Min. = (Kcarrier)* Tdetect.EUTRAN_Inter s.

Kcarrier is the number of E-UTRA inter-frequency carriers indicated by the serving cell.

Qrxlevmin(SIB1) + Qrxlevminoffset(SIB1) +

Pcompensation +sNonIntraSearch

Looking for Higher priority cellat least every (60 * Nlayers) sec.

Looking for all priority cell at least (Kcarrier) * Tdetect,EUTRAN_Inter sec.



17

Eligible cell Selection for measurements : LTE to LTE

inter-freq, UE measurements in the neighbor cell list

• newly detectable EUTRA FDD cells

• In inter-working with Enb::defaultPagingCycle=rf128, detection occure at least every : Kcarrier * Tdetect,EUTRAN_Inter = every Kcarrier * [32 sec ]

• Kcarrier is the number of E-UTRA inter-frequency carriers indicated by the serving cell.

• CellReselectionConfLte:: Qrxlevmin(SIB5) and CellReselectionConfLte:: Qqualmin(SIB5) usagedefined in 3GPP 36.304

• If CellReselectionConfLte:: Qqualmin(SIB5) not present, the UE applies the (default) value of negative infinity for Qqualmin and use only Qrxlevmin(SIB5)

•RSRP

•RSRQ

Qrxlevmin(SIB5)

Qqualmin(SIB5)

•Inter-

FREQ

4G

cell



18

Measurement Configuration for inter-freq reselection : Prerequisite

• If Srxlev > sNonIntraSearchP and Squal > sNonIntraSearchQ then the UE will search for inter-frequency layers of higher priority at least every Thigher_priority_search where Thigher_priority_search is described in section 4.2.2 of Volume 6.

• If Srxlev ≤ sNonIntraSearchP or Squal ≤ sNonIntraSearchQ then the UE will

search for and measure inter-frequency layers of higher, equal or lower priority in preparation for possible reselection.

• Following rules are used by the UE to limit needed measurements :


•t

RSRP

S-ServingCell

Min. = (60* Nlayers) s

Tdetect,EUTRAN_Inter=32s.Min. = (Kcarrier)* Tmeasure,EUTRAN_Inter s

= (Kcarrier)*1,28 s.

Qrxlevmin(SIB1) + Qrxlevminoffset(SIB1) +

Pcompensation +sNonIntraSearchP


Measurements for all priority cell at least every

(Kcarrier) * Tmeasure,EUTRAN_Intersec.



19

Measurement Configuration for inter-freq reselection : Prerequisite


•t

RSRQ

S-ServingCell

Min. = (60* Nlayers) s

Tdetect,EUTRAN_Inter=32s.Min. = (Kcarrier)* Tmeasure,EUTRAN_Inter s

= (Kcarrier)*1,28 s.

Qqualmin(SIB1) + Qqualminoffset(SIB1) +sNonIntraSearchQ


Measurements for all priority cell at least every

(Kcarrier) * Tmeasure,EUTRAN_Intersec.

!Remarque!: Pcompensation is not imply in the reselection decision if RSRQ drive measurements.

Thus pMax is not imply in the reselection decision if RSRQ drive measurements

In LA4.0, one additional threshold with sNonIntraSearchQ usage

Following rules are used by the UE to limit needed measurements :



20

Criteria 1 :

Srxlev of evaluated cell > threshXHigh (SIB5) during a time interval tReselectionRAT

Measurement Configuration for inter freq reselection:Cell Reselection Criteria towards Higher or lower priority cell

� Cell reselection to a cell on a higher priority E-UTRAN frequency or inter-RAT frequency than serving frequency shall be performed if:

• A cell of a higher priority E-UTRAN frequency or inter-RAT frequency fulfils criteria 1

• And more than 1 sec (hardcoded value) has elapsed since the UE camped on the current serving cell (always verified as tReselectionRAT > 1 second).

� Cell reselection to a cell on a lower priority E-UTRAN frequency or inter-RAT frequency than serving frequency shall be performed if:

• No cell on serving frequency or on an equal priority E-UTRAN frequency or on a higher priority E-UTRAN frequency or inter-RAT frequency than serving frequency fulfills the criteria 1

• And SservingCell < threshServingLow and the Srxlev of a cell of a lower priority inter-RAT frequency > threshXLow during a time interval tReselectionRAT

• And more than 1 sec (hardcoded value) has elapsed since the UE camped on the current serving cell.



21

In LA4.0

• Following are newly implemented:

• CellReselectionConfLte ::threshXHighQ

• CellReselectionConfLte ::threshXLowQ

• CellSelectionReselectionConf::threshServingLowQ is applied in all process regarding idle mobility (and also towards GERAN) because this parameter is applied in the serving cell.



22

Criteria 1a :

Squal of evaluated cell > threshXHighQ (SIB5or6) during a time interval tReselectionRAT

Criteria 1b :

Srxlev of evaluated cell > threshXHigh (SIB5or6) during a time interval tReselectionRAT

LA4 -LTE to LTE/Inter-Freq Mobility – Cell Reselection Criteria :Cell Reselection Criteria towards Higher or lower priority cell

1. If threshServingLowQ and threshXHighQ/ threshXLowQ are provided ,

� Cell reselection to a cell on a higher priority E-UTRAN frequency or UTRAN frequency than serving frequency will be performed if:

• A higher priority cell fulfils criteria 1a

• With tReselectionRAT = tReselectionEUTRAN

� Cell reselection to a cell on a lower priority E-UTRAN frequency or inter-RAT frequency than serving frequency will be performed if:

• No cell on a higher priority E-UTRAN frequency or inter-RAT frequency than serving frequency fulfills the criteria 1a

• And SqualservingCell < threshServingLowQ

• And the Squal of a cell of a lower priority inter or UTRAN frequency > threshXLowQduring a time interval tReselectionRAT (tReselectionEUTRAN)



23

Criteria 1a :

Squal of evaluated cell > threshXHighQ (SIB5or6) during a time interval tReselectionRAT

Criteria 1b :

Srxlev of evaluated cell > threshXHigh (SIB5or6) during a time interval tReselectionRAT

LA4 - LTE to LTE/Inter-Freq Mobility – Cell Reselection Criteria :Cell Reselection Criteria towards Higher or lower priority cell

1.

2. If threshServingLowQ and threshXHighQ/threshXLowQ are not provided ,

� Cell reselection to a cell on a higher priority E-UTRAN frequency or UTRAN frequency than serving frequency will be performed if:

• A higher priority cell fulfils criteria 1b

• With tReselectionRAT = tReselectionEUTRAN

� Cell reselection to a cell on a lower priority E-UTRAN frequency or inter-RAT frequency than serving frequency will be performed if:

• No cell on a higher priority E-UTRAN frequency or inter-RAT frequency than serving frequency fulfills the criteria 1b

• And SrxlevservingCell < threshServingLow

• And the Srxlev of a cell of a lower priority inter or UTRAN frequency > threshXLowduring a time interval tReselectionRAT (tReselectionEUTRAN)



24

tReselectionUtra

RSRP Serving Cell

time

UTRAN higher priority target

cell – criteria not met

Criteria1a met LTE inter-freq cell

LTE inter-freq cell is reselected

Qqualmin(SIB5) ++threshXHighQ(SIB5)

LTE to LTE Mobility - Cell Reselection Criteria towards Higher priority eUTRANcell

RSRP or RSRQ Triggers in LA4.0 with new R9 parameter

CPICH Ec/Io1

2

3

Srxlv > 0 and Squal > 0

i.e, Qqualmeas>qQualmin(sib5) and

Qrxlevmeas>qRxlevmin(sib5)+Pcompensation

Criteria is based on neighbor cell level Radio quality



25

tReselectionEUTRANor tReselectionRAT

RSRP Serving Cell

time

Qrxlevmin(SIB1) +Qrxlevminoffset(SIB1)+Pcompensation(SIB5) +sNonIntraSearch(SIB3)

LTE higher priority target

cell – criteria not met

Srxlev > 0

UE starts Inter freq meas(and iRAT) for cell

reselection

•Eutran cell is reselected with other freq

Qrxlevmin(SIB5) +Qrxlevminoffset(SIB1)+Pcompensation(SIB5) +threshXHigh(SIB5)

qrxlevminoffset = 0 if same PLMN

Cell Reselection Criteria towards Higher priority cell

RSRP target cell (higher prio)

Qrxlevmin(SIB1) +Qrxlevminoffset(SIB1)+Pcompensation(SIB5)

+threshServingLow (SIB3)

1

2

3



26

RSRP Serving Cell

time

LTE lower prioritycell – criteria not met

Srxlev > 0

RSRP lower priority eUTRAN cell


reselection


UE starts looking at lower priority cell for reselection

Cell Reselection Criteria towards lower priority cell

Qrxlevmin(SIB5) +Qrxlevminoffset(SIB1)+Pcompensation(SIB5) +threshXHigh(SIB5)


Qrxlevmin(SIB5) +Qrxlevminoffset(SIB1)+Pcompensation(SIB5)+threshXLow(SIB5)



+threshServingLow (SIB3)

1

2

3

4




27

RSRP Serving Cell

time

UTRAN lower prioritycell – criteria not met

CPICH Ec/Io

lower priority UTRAN cell

UE starts IRAT meas (and interfreq) for cell

reselection

Utran cell is reselected with WCDMA Cell

UE starts looking at lower priority cell for reselection

qQualmin(SIB5) +threshXHighQ(SIB5)

tReselectionUtra

qQualmin(SIB5)+threshXLowQ(SIB5)

1

2

3

4

LTE to LTE Mobility - Cell Reselection Criteria towards Lower priority eUTRAN cell

RSRP & RSRQ Triggers in LA4.0 with new R9 parameter

Srxlev > 0 and (for UMTS only) Squal > 0

qQualMin(SIB1) +qQualMinOffset (SIB1) +sNonIntraSearchQ (SIB3)

qQualMin(SIB1) +qQualMinOffset (SIB1) +threshServingLowQ

(SIB3)

Criteria is based on serving cell and neighbor cell level Radio quality

NO CELL



28

Measurement Configuration for inter freq reselection:Ranking between Equal priority cell

� The UE ranks the intra-frequency cells and the cells on other frequencies having equal

priority which fulfil the S-criterion using a criterion known as the R-criterion. The R-

criterion generates rankings Rs and Rn for the serving cell and neighbour cells

respectively:

• For the serving cell: Rs = Qmeas,s + Qhyst,s

• For neighbour cells: Rn = Qmeas,n - Qoff s,n

� The UE reselects to the highest-ranked candidate cell provided that it is better ranked

than the serving cell for at least the duration of Treselection. The UE scales the

parameters Treselection and Qhyst, depending on the UE speed



29

time

RnRs

qOffsetCell

serving cell

neighbor cell

qHyst

ranking computation:we compare a « degraded » neighbour cell (qoffsetcell) to an « improved » serving (qHyst).

Measurement Configuration for inter freq reselection:Ranking between Equal priority cell

Rn > RsRs > Rn Rs > Rn

qHyst – SIB3qOffsetCell – SIB5



30

RSRP Serving Cell

time

LTE equal prioritycell – criteria not met

Srxlev > 0


reselection


Cell Reselection Criteria towards equal priority cell- UE R8



Traditional ”S” criteria


1 4


Rn > Rs

2 UE starts ranking cells

3

qHyst

RSRP equal priority eUTRAN cell

qOffsetCell



31

RSRP Serving Cell

or

RSRQ Serving Cell

time

LTE equal prioritycell – criteria not met

Srxlev > 0

Or

Squal > 0UE starts Inter freq meas

(and iRAT) for cell reselection


Cell Reselection Criteria towards equal priority cell-UE R9if sNonIntraSearchP is not provisioned, sNonIntraSearch is used



AND

Qqualmin(SIB5) +Qqualminoffset(SIB1)


+sNonIntraSearchP

(SIB3)

OR

1 4


Rn > Rs

2 UE starts ranking cells

3

qHyst

RSRP equal priority eUTRAN cell

OrRSRQ equal priority eUTRAN cell …

qOffsetCell

Qqualmin(SIB1) +Qqualminoffset(SIB1)

+sNonIntraSearchQ

(SIB3)



32

qOffsetCell : New Optional parameter implemented

96760, 103792Feature

dB3Value

C--New-set-ups / Optimization - TuningClass/Category

Enumerate in dB

[dB-24, dB-22, dB-20, dB-18, dB-16, dB-14, dB-12, dB-10, dB-8, dB-6, dB-

5, dB-4, dB-3, dB-2, dB-1, dB0, dB1, dB2, dB3, dB4, dB5, dB6, dB8, dB10,

dB12, dB14, dB16, dB18, dB20, dB22, dB24]

Range & Unit

ENBEquipment/ Enb/ LteCell/ LteNeighboring/

LteNeighboringFreqConf/ LteNeighboringCellRelation

Object

qOffsetCell

Parameter

• In general, this parameter is not implemented

• qOffsetCell : This parameter defines the offset between the current LteCell and the LteNeighboringCell. This parameter will be present and configured if the neighbor cell is included in the neighbor cell list to be provided in the System Information. In dB. Defined in TS 36.331. Broadcast in SystemInformationBlockType4, or in SystemInformationBlockType5..

• there exists at least one instance of LteCell/LteNeighboringCellRelation containing mandatory parameters for cell reselection

• This parameter will be broadcasted if qOffsteCell is set with non dB0 value

• For sib5 qOffsetCell can be empty.// To see section 4.1.3.3 of the LPUG for details on this parameter



33

Feature inter-working : Optional InterFreqBlackCellList

of SIB5

• Related to inter-working with inter-frequency mobility: interFreqNeighCellList, contains the neighboring cells have attribute qOffsetCell set as non-zero, and noHoOrReselection set as FALSE. If no such cell, this IE is not included.

• interFreqBlackCellList, contains the neighboring cells have attribute noHoOrReselection set as TRUE and the cells in the object of black cell list.

If no such cell, this IE is not included

• InterFreqBlackCellList that is a sequence of PhysCellIdRange

LTENeighboringFreqConf

(one or More Instances not pointed

to by LteCell::lteNeighboringFreqsConfId)

LteNeighboringCellRelation

(one or more instances, Optional)

noHOOrReselection

qOffsetCell(SIB5)

BlackCellConf

(one or more instances, Optional)

range

start

•LteCell

CellSelectionReselectionConf

qHyst(SIB3)



34

Some related features

• 104002 Broadcast per cell SIB4 (LA3.0)

is broadcast only if at least one neighbour EUTRAN carrier MO has been configured.

Possibilities to blacklist a cell or group of cell



35

Implementation Principle

• Inter-freq reselection will use the same procedure as existing for intra-freq reselection, but with specific parameters for the thresholds.

• Inter-freq handover will use the same procedure as existing intra-freq handover.



36


Antoine GUIRAUDDecember, 2012

103792 Intra-LTE Inter-freq Mobility - Connected mode



37

Overview

• Feature flag

• isInterFreqEutraSameFrameStructureMobilityAllowed

Note: this flag is not used for target eNB to check incoming handover in LA3.0.

• Type of mobility:

• Inter-freq cell reselection (by SIB5);

• Inter-freq non-blind handover (triggered by A3/A5)

• Inter-freq non-blind redirection (triggered by A3/A5);

• Inter-freq blind redirection (triggered by A2);

• No inter-freq blind handover;

• Type of inter-freq:

• Intra-band intra-FDD (or TDD)

• Inter-band intra-FDD (or TDD)

• No inter-FDD-TDD in LA3.0



38

• Type of handover base:

• X2-based inter-freq handover

• S1-based inter-freq handover

• No intra-eNB inter-freq handover in LA3.0

Overview



39

• RF-Parameters

• This field indicates the supported band list;

• MeasParamters

• This field indicates if gap is required when UE stays in band of serving freq and measures band of target freq;

• Feature Group Indicator

• Bit 13, this bit indicates if UE supports inter-freq handover;

• Bit 14, this bit indicates if UE supports event A4 and A5;

• Bit 25, this bit indicates if UE supports inter-freq measurement;

UE Capability



40

Implementation Principle

• Principle:

• Non-blind inter-freq handover and redirection use the same measurement;

• Redirection is performed only when handover can’t be triggered;

• Measurement for inter-freq handover/redirection is configured to UE in the same RRC message with measurement for inter-RAT handover/redirection/CCO;

• Inter-freq measurement and inter-RAT measurement are configured to UE only when serving cell condition is bad, and so they should be de-configured once the condition becomes good.

• If serving cell condition is worse, blind redirection will be triggered.

• Inter-freq and inter-RAT measurement comes from MIM and are selected by eMCTA.

• Inter-freq handover will use the same procedure as existing intra-freq handover.



41

Measurement Configuration

• Entering-Coverage-Alarm

• Event A2 is used, if this report is received, the eNB configures inter-freq and inter-RAT measurement to UE, and setup gap if it is required;

• Gap required or not depends on UE capability;

• Leaving-Coverage-Alarm

• Event A1 is used, if this report is received, the eNB remove configured inter-freq & inter-RAT measurement and release gap if it is setup before.

• Below-Serving-Floor

• Event A2 is used, if this report is received, the eNB triggers blind redirection to inter-freq or inter-RAT.

• Threshold of this measurement should be lower than that for entering-coverage-alarm.

• Target frequency for blind redirection is selected by eMCTA.

• Mobility-Intra-Freq

• Event A3 is used, if this report is received, the eNB triggers intra-freq handover.



42

Measurement Configuration

• Mobility-Inter-Freq-to-EUTRA

• Event A3 or A5 is used, if this report is received, the eNB triggers inter-freq handover or redirection.

• If both A3 and A5 are configured in MIM, A5 is configured to UE if it is supported by UE (by checking UE capability)

• Redirection is triggered only if inter-freq handover is not supported by UE (by checking UE capability)

• The inter-freq configured to UE for measurement are selected by eMCTA from neighbouring inter-freq configured in MIM.



43

Handover and measurement report interaction• During inter-eNB inter-freq handover, if following report is received:

• Leaving-coverage-alarm(A1), cancel the ongoing inter-freq handover;

• Below-serving-floor(A2), ignore this report;

• Mobility-intra-freq(A3), trigger intra-freq handover and cancel the ongoing inter-freq handover;

• Mobility-inter-freq-to-EUTRA(A3/A5):

• If reported freq is the same as that of ongoing handover, check the reported target cell, if still the same, ignore this report, otherwise cancel the ongoing handover and trigger new handover;

• If reported freq is a different one, check its priority assigned by eMCTA, ignore this report if it is a lower or equal priority, otherwise cancel the ongoing handover and trigger new inter-freq handover;

• Mobility-inter-RAT(B2), check freq priority assigned by eMCTA, ignore this report if it is a lower priority freq, otherwise cancel the ongoing inter-freq handover and trigger inter-RAT handover;



44

Handover and measurement report interaction

• During other type of handover, if mobility-inter-freq report is received:

• Intra-freq handover, ignore the report;

• Inter-RAT handover, check freq priority assigned by eMCTA, ignore this report if it is a lower priority freq, otherwise cancel the ongoing inter-RAT handover and trigger inter-freq handover;



45

Some related features

• 97981 Intra-LTE handover optimization

This feature introduce several optimization on handover procedure, including both intra-freq and inter-freq handover.

• 93270 Measurement gap

Measurement gap allow UE measuring neighbouring inter-freq or inter-RAT.

• 106136 eMCTA

eMCTA selects inter-freq that should be measured and target freq that should be redirected to.



46


Antoine GUIRAUDDecember, 2011

Measurements



47

Event A1

• When event A1 is configured, UE will send measurement reports when the serving cell becomes better than a threshold value. Event A1 is used for UE ‘Leaving-Coverage-Alarm’ monitoring

• Event A1 entering condition:

Ms – hysteresis > thresholdEutraRsrp/thresholdEutraRsrq

• Event A1 leaving condition:

Ms + hysteresis < thresholdEutraRsrp/thresholdEutraRsrq

Ms: measurement result of the serving cell

hysteresis: defined in reportConfigEUTRA::hysteresis

thresholdEutraRsrp: used if Rsrp is used for Ms. Defined inreportConfigEUTRA::thresholdEutraRsrp.

thresholdEutraRsrq: used if Rsrq is used for Ms. Defined inreportConfigEUTRA::thresholdEutraRsrq.



48

Event A1 Diagram

time

Ms

thresholdEutraRsrp/thresholdEutraRsrq

serving cell

hysteresis

conditions for Ms fulfilled

timeToTriggerreportInterval

reportOnLeave

reportAmount

reportQuantity

timeToTrigger

reportQuantity, reportAmount, timeToTrigger, reportInterval are defined in ReportConfigEutra MO



49

Event A2

• When event A2 is configured, UE will send measurement reports when the serving cell becomes worse than a threshold value. Event A2 is used for UE ‘Entering-Coverage-Alarm’ and ‘Below-Serving-Floor’ monitoring




Ms - hysteresis > thresholdEutraRsrp/thresholdEutraRsrq

Ms: measurement result of the serving cell


thresholdEutraRsrp: used if Rsrp is used for Ms. Defined inreportConfigEUTRA::thresholdEutraRsrp.

thresholdEutraRsrq: used if Rsrq is used for Ms. Defined inreportConfigEUTRA::thresholdEutraRsrq.



50

Event A2 Diagram


time


reportAmount

reportQuantity

reportOnLeave

timeToTrigger

Ms

hysteresis

serving cell





51

Event A3

• When event A3 is configured, UE will send measurement reports when the neighbor cell becomes offset better than the serving cell. Event A3 is used to trigger intra-frequency HO and inter-frequency redirection/HO if UE does not support event A5 configuration.


Mn > Ms + offset + hysteresis


Mn < Ms + offset – hysteresis

offset = eventA3Offset + cellIndividualOffset_s + offsetFreq_s –cellIndividualOffset_n – offsetFreq_n

Mn: measurement result of the neighbor cell.

Ms: measurement result of the serving cell.


eventA3Offset: defined in reportConfigEUTRA::eventA3Offset



52

Event A3 Diagram


time

MnMs

offset

serving cell

neighbor cell

hysteresis


reportOnLeave

reportAmount

reportQuantity

timeToTrigger



53

Event A3 Diagram: use case entering condition, with current values : RSRP


time

MnMs

MeasObjectEUTRA::offsetFreq : dB0

serving cell

neighbor cell

reportConfigEUTRA::hysteresis : 2.0

timeToTrigger:ms40

reportInterval: ms240

reportAmount

reportQuantity


::cellIndividualOffset: dB0


LteNeighboringCellRelation::cellIndividualOffset : dB0

reportConfigEUTRA::eventA3Offset : 2.0

Trigger EventA3



54

Event A3 Diagram: use case Focus on leaving condition, with current values : RSRP


time

MnMs


serving cell

neighbor cell

reportConfigEUTRA::hysteresis : 2.0

timeToTrigger:ms40 reportOnLeave

reportQuantity


::cellIndividualOffset: dB0


LteNeighboringCellRelation::

cellIndividualOffset : dB0

reportConfigEUTRA::eventA3Offset : 2.0

EventA3 Leaving



55

Event A5

• When event A5 is configured, UE will send measurement reports when the serving becomes worse than threshold1 and inter-frequency neighbor cell becomes better than threshold2. Event A5 is used to trigger inter-frequency redirection/HO and intra-frequency with ANR. (Refer to LPUG Volume 6)

• Event A5 entering condition 1:


• Event A5 entering condition 2:

Mn + offset – hysteresis > threshold2EutraRsrp/threshold2EutraRsrq

• Event A5 leaving condition 1:

Ms – hysteresis > thresholdEutraRsrp/thresholdEutraRsrq

• Event A5 leaving condition 2:

Mn + offset + hysteresis < threshold2EutraRsrp/threshold2EutraRsrq

offset = cellIndividualOffset_n – offsetFreq_n



56

Event A5 Diagram


time

MnMs


threshold2EutraRsrp/threshold2EutraRsrq

hysteresis

serving cell

neighbor cellhysteresis

offset


conditions for Mn fulfilled


reportOnLeave

reportAmount

reportQuantity

timeToTrigger



57



Backup



58



Optional UE speed Management



59

Speed Mobility Management– Cell Reselection – tReselectionRATGeneral Feature Activation strategy (1/3)

• HRPD case:

tReselectionRAT = tReselectionCdmaHrpd * (tReselectionHrpdSfHigh or tReselectionHrpdMedium)

• Inter-freq case:

tReselectionRAT = tReselectionEUTRAN * (tReselectionEutraSfHigh or tReselectionEutraSfMedium)



60

Mobility between LTE and LTE inter freq–Cell Reselection –

tReselectionRAT [cont.] General Feature Activation strategy (2/3)

• The UE Speed Management is doing by the parameters under SpeedStateEvalConf and LteNeighboringFreqConf/ LteSpeedDependentConf :

• LteSpeedDependentConf::tReselectionEutraSfMedium(sib5) = 0.5

• LteSpeedDependentConf::tReselectionEutraSfHigh(sib5) = 0.25

During tEvaluation (Tcrmax)

[Nb. Reselections] > nCellChangeHigh (NCR_H)

•t

High mobility state criteriatEvaluation(sib3)


NCR_M < [Nb. Reselections] < nCellChangeHigh

•t

Medium mobility state criteriatEvaluation

During tHystNormal (TcrmaxHyst)

[Nb. Reselections] < nCellChangeMedium (i.e NCR_M)

•t

Normal reselectionstHystNormal

1

2

tR:2s

tR:1s

tR:0.5s

tReselectionEUTRAN×

tReselectionEutraSfHigh

tReselectionEUTRAN×

tReselectionEutraSfMedium

tReselectionEUTRAN3



61

Mobility between LTE and HRPD – Cell Reselection – tReselectionRAT

[cont.] General Feature Activation strategy (3/3)

• The UE Speed Management is doing by the parameters under SpeedStateEvalConf and HRPDNeighboring/ HrpdSpeedDependentConf :

• HrpdSpeedDependentConf:: tReselectionHrpdMedium(sib8) = 0.5

• HrpdSpeedDependentConf:: tReselectionHrpdSfHigh(sib8) = 0.25


[Nb. Reselections] > nCellChangeHigh (NCR_H)

•t

High mobility state criteriatEvaluation(sib3)


NCR_M < [Nb. Reselections] < nCellChangeHigh

•t

Medium mobility state criteriatEvaluation

During tHystNormal (TcrmaxHyst)

[Nb. Reselections] < nCellChangeMedium (i.e NCR_M)

•t

Normal reselectionstHystNormal

1

2

tre:2s

tre:1s

tre:0,5stReselectionCdmaHrpd

×tReselectionHrpdSfHigh

tReselectionCdmaHrpd×

tReselectionHrpdMedium

tReselectionCdmaHrpd3



62

UE speed state transition Algorithme

criteria for High-mobility

state is detected?

criteria for Medium-mobility

state is detected?

enter High-mobility state.

Apply Speed dependent

ScalingFactor for High-mobility state

enter Medium-mobility state.

Apply Speed dependent

ScalingFactor for Medium-mobility state

Normal-mobility state.

no scaling is applied.

Yes

No

either Medium- or High-mobility state

is not detected during

time period tHystNormal (TCRmaxHyst)

Yes

No



63

5.2.4 Cell Reselection evaluation process

5.2.4.1 Reselection priorities handling

Absolute priorities of different E-UTRAN frequencies or inter-RAT frequencies may be provided to the UE in the system information, in the RRCConnectionRelease message, or by inheriting from another RAT at inter-RAT cell (re)selection. In the case of system information, an E-UTRAN frequency or inter-RAT frequency may be listed without providing a priority (i.e. the field cellReselectionPriority is absent for that frequency). If priorities are provided in dedicated signalling, the UE shall ignore all the priorities provided in system information. If UE is in camped on any cell state, UE shall only apply the priorities provided by system information from current cell, and the UE preserves priorities provided by dedicated signalling unless specified otherwise. When the UE in camped normally state, has only dedicated priorities other than for the current frequency, the UE shall consider the current frequency to be the lowest priority frequency (i.e. lower than the eight network configured values). While the UE is camped on a suitable CSG cell, the UE shall always consider the current frequency to be the highest priority frequency (i.e. higher than the eight network configured values), irrespective of any other priority value allocated to this frequency. The UE shall delete priorities provided by dedicated signalling when:

- the UE enters RRC_CONNECTED state; or

- the optional validity time of dedicated priorities (T320) expires; or

- a PLMN selection is performed on request by NAS [5].

NOTE: Equal priorities between RATs are not supported.

Extract from TS 36.304 (procedures for Idle-Mode)

9b-kts l103792 sib5 inter-freq reviewed

Documents

alcatellucent confidential

proprietary use pursuant

authorized persons

freq cell reselection

interfreq cell reselection2

company instruction7one

cell state

main parameter