Group Communication System Enablers for LTE (GCSE_LTE); Stage 2
The present document provides the stage 2 description for the 3GPP system provided enablers to support group communication services using EUTRAN access. The corresponding stage 1 requirements are defined in TS 22.468 [2].
The group communication system is represented by an Application Server (GCS AS) using the 3GPP system provided enablers for transferring its application signalling and for delivering application data, e.g. media data, to a group of UEs either (i) over MBMS Bearer Services using the Broadcast Mode of MBMS (TS 23.246 [3]); or (ii) over EPS Bearers; or (iii) over both MBMS and EPS bearer services.
The specification covers both roaming and non-roaming scenarios and also includes support for service continuity, i.e. support for continuous reception of application data when a UE changes between reception of application data via EPS and MBMS Bearer Services.
Application level interactions between the UE and the GCS Application Server are out of scope of this specification.