8.5.27 MBMS frequency selection

25.3313GPPProtocol specificationRadio Resource Control (RRC)Release 17TS

The UE shall perform the MBMS frequency layer selection procedure upon receiving the IE "MBMS Preferred frequency information", when specified explicitly e.g. as in subclause 8.6.9.2, or when the priority for an MBMS service as indicated by upper layers changes.

The UE shall:

1> if there exist two or more preferred frequencies for services included in variable MBMS_ACTIVATED_SERVICES:

2> request from upper layers the priorities of the different MBMS services included in variable MBMS_ACTIVATED_SERVICES for which a preferred frequency has been received.

1> if the UE is in idle mode:

2> if a preferred frequency layer applies for a service included in variable MBMS_ACTIVATED_SERVICES:

3> select the preferred frequency indicated for the MBMS service(s) prioritised most by upper layers for which a preferred frequency exists as the preferred frequency.

1> if the UE is in CELL_FACH, CELL_PCH or URA_PCH state; and

1> if there exists one or more preferred frequencies for services included in variable MBMS_ACTIVATED_SERVICES and the variable MBMS_PL_SERVICE_RESTRICTION_INFO_DEDICATED is set to FALSE:

2> if the IE "RAB information" in the variable ESTABLISHED_RABS is not empty:

3> if the current frequency is the frequency corresponding with the preferred frequency indicated for the MBMS service(s) prioritised most by upper layers for which a preferred frequency exists:

4> select the current frequency as the preferred frequency.

3> else:

4> if there exists one or more preferred frequencies for services included in variable MBMS_ACTIVATED_SERVICES for which the IE "MBMS PL Service Restriction Information" has not been received in the MBMS GENERAL INFORMATION message:

5> select the preferred frequency indicated for the MBMS service(s) prioritised most by upper layers for which a preferred frequency exists for which the IE "MBMS PL Service Restriction Information" has not been received in the MBMS GENERAL INFORMATION message as the preferred frequency.

2> else:

3> select the preferred frequency indicated for the MBMS service(s) prioritised most by upper layers for which a preferred frequency exists as the preferred frequency.

1> if the UE is in CELL_DCH:

2> if there exists one or more preferred frequencies for services included in variable MBMS_ACTIVATED_SERVICES and the variable MBMS_PL_SERVICE_RESTRICTION_INFO_DEDICATED is set to FALSE:

3> if the current frequency does not correspond to the preferred frequency indicated for the MBMS service(s) prioritised most by upper layers for which a preferred frequency exists:

4> select as preferred frequency the preferred frequency indicated for the MBMS service(s) prioritised most by upper layers for which a preferred frequency exists for which the IE "MBMS PL Service Restriction Information" is not included in the MBMS GENERAL INFORMATION message;

4> if a preferred frequency has been selected and the current frequency is different from the selected frequency:

5> request UTRAN to be moved to the preferred frequency by means of the MBMS MODIFICATION REQUEST message as specified in subclause 8.7.6;

5> if the variable MBMS_PREV_FREQUENCY_INFO is empty:

6> upon receiving a request to move to the requested preferred frequency, store the frequency information of the frequency on which the UE was operating prior to the hard-handover to the preferred frequency in the variable MBMS_PREV_FREQUENCY_INFO.

1> if a preferred frequency has been selected:

2> if the UE is not in CELL_DCH state:

3> apply the cell-reselection procedure as described in [4], using the received "MBMS Preferred frequency information" applicable to the selected frequency;

3> if the UE re-selects to a cell on the indicated preferred frequency:

4> if HCS is not used, and the IE "Qoffmbms" is not present for the MBMS preferred frequency:

5> consider the cells on the MBMS preferred frequency having a Qoffmbms equal to "infinity".

4> if HCS is used, and the IE "HCS_OFFmbms" is not present for the MBMS preferred frequency:

5> consider the cells on the MBMS preferred frequency having the highest HCS priority level.

4> if the UE is in CELL_FACH, CELL_PCH or URA_PCH:

5> act according to subclause 8.3.1.2.

4> if the selected frequency is different to the frequency on which the UE was previously operating; and

4> if the variable MBMS_PREV_FREQUENCY_INFO is empty:

5> store the frequency information of the frequency on which the UE was operating prior to cell-reselection to the preferred frequency in the variable MBMS_PREV_FREQUENCY_INFO.

4> apply the MCCH acquisition procedure, as specified in subclause 8.7.2.

1> else:

2> if the UE is not in CELL_DCH state:

3> stop applying any "MBMS Preferred frequency information".

3> if the UE is not redirected to another frequency; and

3> if the UE does not decide to receive an MBMS service; and

3> if the variable MBMS_PREV_FREQUENCY_INFO is not empty:

4> if any frequency in SIB11 or SIB12 has the same frequency stored in the variable MBMS_PREV_FREQUENCY_INFO:

5> select a suitable UTRA cell in that frequency;

5> if no suitable UTRA cell in that frequency is found:

6> select a suitable UTRA cell in another frequency.

4> if no frequency in SIB11 or SIB12 has the same frequency stored in the variable MBMS_PREV_FREQUENCY_INFO:

5> select a frequency randomly among the inter-frequencies indicated in SIB11 or SIB12:

6> select a suitable UTRA cell in the selected frequency;

6> if no suitable UTRA cell in the selected frequency is found:

7> select a suitable UTRA cell in another frequency.

4> clear the variable MBMS_PREV_FREQUENCY_INFO.

NOTE: The UE is only required to acquire the relevant SIB11 or SIB12, according to what is specified in subclauses 8.1.1.6.11 and 8.1.1.6.12.