8.39 MBMS UE Linking

25.4133GPPRelease 17TSUTRAN Iu interface Radio Access Network Application Part (RANAP) signalling

8.39.1 General

The purpose of the MBMS UE Linking procedure is to make the RNC aware that a given UE, with existing Iu-ps signalling connection, joined and/or left one or several Multicast Services.

The procedure uses connection oriented signalling.

8.39.2 Successful Operation

Figure 51: MBMS UE Linking procedure. Successful operation.

The CN initiates the procedure by sending a MBMS UE LINKING REQUEST message.

The MBMS UE LINKING REQUEST message shall contain the following IEs:

– a list of one or several TMGIs, each identifying the MBMS Bearer Service that the UE joined or left and which has not yet been linked or unlinked respectively in the UTRAN;

– for each of the MBMS Bearer Services that the UE joined;

– the PTP RAB ID.

Upon reception of the MBMS UE LINKING REQUEST message, for each TMGI received identifying the MBMS Bearer Service that the UE joined and which has not yet been linked in the UTRAN, the RNC shall perform the corresponding UE linking as described in TS 25.346 [42].

Upon reception of the MBMS UE LINKING REQUEST message, for each TMGI received identifying the MBMS Bearer Service that the UE left and which has not yet been de-linked in the UTRAN, the RNC shall perform the corresponding UE de-linking as described in TS 25.346 [42].

After handling all received TMGI(s), the RNC shall only report to the CN in the MBMS UE LINKING RESPONSE message the unsuccessful linking(s)/de-linking(s) with an appropriate cause value e.g. "MBMS – UE Linking Already Done", "MBMS – UE De-Linking Failure – No Existing UE Linking".

Transmission and reception of a MBMS UE LINKING RESPONSE message terminate the procedure in the UTRAN and in the CN respectively.

8.39.3 Unsuccessful Operation

The unsuccessful operation for this Class 1 Elementary procedure is described under the Successful Operation chapter.

8.39.4 Abnormal Conditions

Upon reception of the MBMS UE LINKING REQUEST message, if for a given TMGI received identifying the MBMS Bearer Service that the UE joined, the linking has already been done in the UTRAN, the RNC shall consider this linking as unsuccessful but shall proceed with the other ones.

Upon reception of the MBMS UE LINKING REQUEST message, if a given TMGI received identifying the MBMS Bearer Service that the UE left, cannot be found in the UE context, the RNC shall consider this de-linking as unsuccessful but shall proceed with the other ones.