MBMS technology has already been introduced in UMTS and it is adapted in LTE as well. MBMS technology has few nodes and new interfaces to inter work with LTE network. BMSC, MBMS-GW, MCE are key nodes of MBMS network defined for LTE.
I know few interfaces as following:
1. M1 Interface: This interface is used to transport multicast IP packets towards eNodeB
2. M2 Interface: This interface is used between enodeB and MCE. MCE stands for multi cell co-ordination entity and responsible to make co-ordination between cells.
3. M3 Interface: This interface is used to exchange signalling messages between MME and MCE for an MBMS session.