A.1 General requirements and recommendations

3GPP43.246Multimedia Broadcast/Multicast Service (MBMS) in the GERANRelease 17Stage 2TS

A.1.1 General requirements

1) MBMS shall utilise the radio resource in an efficient manner.

2) MBMS data transfer shall be downlink only.

3) The reception of MBMS data blocks in p-t-m is not guaranteed at the GERAN level. MBMS does not support individual retransmissions at the radio link layer. This does not preclude the periodic repetitions of the MBMS content based on operator or content provider scheduling or retransmissions based on feedback at the radio level and/or at the application level.

4) Simultaneous reception of MBMS and non-MBMS services shall be possible and shall depend upon mobile station capabilities.

5) Simultaneous transmission of more than one MBMS service shall be possible and the reception shall depend upon mobile station capabilities.

6) Mobile station controlled "service based" cell selection/reselection shall not be permitted.

7) A mechanism to enable the network to move MBMS subscribers, in an MBMS session, between RATs and cells is required.

8) Supported QoS attributes shall be the same for MBMS Multicast and Broadcast modes.

9) During MBMS data transmission it shall be possible to page a given mobile station, irrespective of the RRC state / RR mode of operation.

10) The MBMS Notification procedure shall be used to indicate the start (and potentially about the ongoing) of MBMS data transmission in the cell.

10a The mobile station shall return to DRX mode (if it was in DRX mode before receiving the notification) in case no bearer establishment for that particular session has been received before a given time. A maximum time limit needs to be defined on the network side between notification and bearer establishment.

10b The mobile station shall disregard a notification for which no bearer establishment has been received before a given time

10c Mobile station reaction upon notification must be done on a session basis, in which case means must exist to distinguish in the network the mobile station responses per session

10d Due to capacity reasons, GERAN shall be able in any particular cell within the service area, not to notify the session start of a given session hence not to transfer this session at all

11. A mechanism shall be defined to enable the network to start the MBMS data transmission for a multicast session in a cell if there is at least one user joined to this multicast session in the cell.

12. A mechanism shall be defined to allow the network to stop the MBMS data transmission for a given multicast session in a cell which does not contain any MBMS mobile station joined to this multicast session.

13. Continuing the acquisition of a given MBMS service after cell change within the MBMS service area shall be possible.

A.1.2 General recommendations

1) MBMS should maximise the reuse of existing channels.

2) The GERAN should provide mechanisms to reduce the MBMS outage for a mobile station at cell change.

3) Header compression should be supported.