Establishes the relationship between the user and the service provider, which allows the user to receive the related MBMS multicast service.
Service Subscription is the agreement of a user to receive service(s) offered by the operator. Subscription information is recorded in the BM-SC. Subscription information and other BM-SC functionality may be on separate entities, which is enabled by proxy capability of the Gmb interface.
MBMS user service announcement/discovery mechanisms shall allow users to request or be informed about the range of MBMS user services available. This includes operator specific MBMS user services as well as services from content providers outside of the PLMN. Service announcement is used to distribute to users information about the service, parameters required for service activation (e.g. IP multicast address(es)) and possibly other service related parameters (e.g. service start time).
Operators/service providers may consider several service discovery mechanisms. This could include standard mechanisms such as SMS, or depending on the capability of the terminal, applications that encourage user interrogation. The method chosen to inform users about MBMS user services may have to account for the user' s location, (e.g. current cell, in the HPLMN or VPLMN). Users who have not already subscribed to a MBMS user service should also be able to discover MBMS user services.
The following could be considered useful for MBMS user service announcement mechanisms (not exhaustive):
SMS Cell Broadcast to advertise MBMS Multicast and Broadcast user services;
MBMS Broadcast mode to advertise MBMS Multicast and Broadcast user Services;
MBMS Multicast mode to advertise MBMS Multicast user Services;
PUSH mechanism (WAP, SMS-PP, MMS);
URL (HTTP, FTP).
The details of the MBMS service announcement mechanisms are out of scope of this specification, but MBMS shall allow the utilisation of solutions using IETF protocols.
Service announcement is further defined within MBMS User Service specifications TS 26.346
Joining (i.e. MBMS multicast activation by the user) is the process by which a subscriber joins (becomes a member of) a multicast group, i.e. the user indicates to the network that he/she wants to receive Multicast mode data of a specific MBMS bearer service. An MBMS user service may also be carried by more than one MBMS bearer service. In that case the MBMS user service part in the UE initiates the relevant MBMS bearer services to receive the service (see clause 8.2
Session Start is the point at which the BM-SC is ready to send data. This can be identified with the start of a "Multicast session"
as defined in TS 22.146
. Session Start occurs independently of activation of the service by the user - i.e. a given user may activate the service before or after Session Start. Session Start is the trigger for bearer resource establishment for MBMS data transfer. If an MBMS user service is carried by more than one MBMS bearer service, a Session Start message is sent for each MBMS bearer service. In that case the UE may need to initiate the reception of multiple relevant MBMS bearer services to receive the MBMS user service.
Informs the UEs about forthcoming (and potentially about ongoing) MBMS multicast data transfer.
It is the phase when MBMS data are transferred to the UEs.
It is the point at which the BM-SC determines that there will be no more data to send for some period of time - this period being long enough to justify removal of bearer resources associated with the session. At Session Stop, the bearer resources are released.
Leaving (i.e. MBMS multicast deactivation by the user) is the process by which a subscriber leaves (stops being a member of) a multicast group, i.e. the user no longer wants to receive Multicast mode data of a specific MBMS bearer service.