4.2 Reference Architecture Model
23.2463GPPArchitecture and functional descriptionMultimedia Broadcast/Multicast Service (MBMS)Release 17TS
4.2.1 GPRS
Note 1: Network entities and reference points solely used by the MBMS user service (e.g. for service announcement as described in clause 4.4.1.2) are not shown in this figure.
Note 2: Gp applies only when SGSN and GGSN are in different PLMNs.
Note 3: the Iu/Gn reference point above is a direct tunnel according to clause 5.6.2.2, figure 6b in TS 23.060 [15] with IP multicast based addressing according to RFC 4607 [21].
Figure 1a: Reference architecture for GPRS to support the MBMS bearer service with GERAN and UTRAN
4.2.2 EPS
Figure 1b: Reference architecture for Evolved Packet System with E-UTRAN and UTRAN (MBMS Broadcast Mode only)
NOTE 1: In addition to MBMS Bearers (over SGmb/SGi-mb), the BM-SC may use EPS Bearers (over SGi) to realize an MBMS User Service as specified in TS 26.346 [7].
NOTE 2: The MCE (see TS 36.300 [17]) is not shown in the figure.
NOTE 3: MBMS service over Gn-SGSN is supported when the MBMS-GW is co-located with the PDN GW and this PDN GW has the necessary GGSN functions to control the MBMS Bearer Service over Gn.