7 Functions of M3 interface for MBMS
36.4403GPPEvolved Universal Terrestrial Radio Access Network (E-UTRAN)General aspects and principles for interfaces supporting Multimedia Broadcast Multicast Service (MBMS) within E-UTRANRelease 17TS
“M3” Interface: MME – MCE
M3 provides the signalling service between MCE and MME that is required to fulfil the M3AP functions listed in TS 36.444 . SCTP (IETF RFC 4960 ) is used as signaling transport i.e. Point-to-Point signaling is applied.
7.2 MBMS Session management function
MBMS session management function is responsible for starting, updating, and stopping MBMS sessions.
7.2.1 M3 service context management function
The M3 service context management function supports the establishment of the necessary E-MBMS service context including E-MBMS E-RAB context, M3 signalling connection ID(s), etc.
The establishment of the M3 service context is initiated by the MME. The M3 service context management function also supports the release of the context previously established in the MCE due to service termination. The release of the M3 context is triggered by the MME.
7.2.2 MBMS E-RAB management functions
The E-MBMS E-RAB service management function is responsible for establishing and releasing E-UTRAN resources for E-MBMS services. The establishment of E-UTRAN resources is triggered by the MME and requires respective QoS information to be provided to the MCE. The release of E-UTRAN resources is triggered by the MME.
7.3 M3 interface reset and error processing function
These functions allow for managing of signalling associations between MME-MCE, surveying M3 interface and recovering from errors.
7.3.1 Error indication
The error indication function is used by the MCE (respectively the MME) to indicate to the MME (respectively the MCE) that a logical error has occurred.
The reset function is used to initialize the peer entity after node setup or after a failure event occurred. The reset function may also be used to initialize part of the peer entity. This procedure can be used by both the MCE and MME.
7.4 M3 interface setup and configuration update functions
In distributed MCE architecture, the M3 Setup and MCE Configuration Update functions may be used to exchange (respectively update) application level data used for the operation of the M3 interface after the TNL association has become operational.