10A Additional MBMS procedures
24.3803GPPMission Critical Push To Talk (MCPTT) media plane controlProtocol specificationRelease 18TS
10A.1 Group dynamic data notifications
Prior to using the MBMS bearer the participating MCPTT function needs to activate the MBMS bearer and announce the MBMS bearer as described in clause 4.1.3. The participating MCPTT function uses the listening status reports to decide for which users the participating MCPTT function sends the group dynamic data notifications over MBMS, and for which users the participating MCPTT function continues to use unicast bearers.
This procedure is used when MCPTT clients subscribe to group dynamic data. When the terminating participating function receives a SIP NOTIFY request towards a user listening to the MBMS subchannel that comes from the controlling MCPTT function and is related to a subscription for group dynamic data, the participating MCPTT function shall:
1. respond to the SIP NOTIFY request with a SIP 200 (OK) request;
2. map the information in the SIP NOTIFY request to the information elements in clause 8.5.3; and
3. send the Group Dynamic Data Notify message over the MBMS bearer.