8.41 MBMS CN De-Registration

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

8.41.1 General

The purpose of the MBMS CN De-Registration procedure is to make the RNC aware that a certain Multicast Service is no longer available. The MBMS CN De-Registration procedure is triggered by the CN (PS domain).

The procedure uses connectionless signalling.

8.41.2 Successful Operation

Figure 54: MBMS CN De-Registration procedure. Successful operation.

The CN initiates the procedure by sending a MBMS CN DE-REGISTRATION REQUEST message.

The MBMS CN DE-REGISTRATION REQUEST message shall contain the following IEs:

– TMGI;

– Global CN-ID IE, only when the MBMS CN DE-REGISTRATION REQUEST message is sent from a CN node towards an RNC for which the sending CN node is not the default CN node.

If the Global CN-ID IE is not included, the MBMS CN DE-REGISTRATION REQUEST message shall be considered as coming from the default CN node.

Upon reception of the MBMS CN DE-REGISTRATION REQUEST message, the RNC shall remove all associated MBMS context(s) and resources corresponding to the MBMS Bearer Service identified by the indicated TMGI and shall report it to the CN by sending the MBMS CN DE-REGISTRATION RESPONSE message.

Upon reception of the MBMS CN DE-REGISTRATION REQUEST message, if no existing MBMS Bearer Service can be identified by the indicated TMGI in the RNC, it shall consider this MBMS CN De-Registration procedure unsuccessful and shall report it to the CN by sending the MBMS CN DE-REGISTRATION RESPONSE message with the appropriate cause value e.g. "TMGI unknown".

The MBMS CN DE-REGISTRATION RESPONSE message shall contain the Global RNC-ID IE and the same TMGI as received in the MBMS CN DE-REGISTRATION REQUEST message.

Transmission and reception of a MBMS CN DE-REGISTRATION RESPONSE message terminate the procedure in the UTRAN and in the CN respectively.

8.41.3 Unsuccessful Operation

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

8.41.4 Abnormal Conditions

If NNSF is active, the RNC may receive from several CN nodes for a certain MBMS Bearer Service the MBMS CN DE-REGISTRATION REQUEST message. In this case the RNC will only proceed with the first MBMS CN DE-REGISTRATION REQUEST message received and will inform the respective CN nodes accordingly i.e. with MBMS CN DE-REGISTRATION RESPONSE message and cause value "TMGI unknown" to all the CN nodes except the one towards which the RNC confirmed the successful the MBMS CN De-Registration procedure with MBMS CN DE-REGISTRATION RESPONSE message including no cause value.