It is one of the most exciting service, operator would like to provide in their LTE network. MBMS is acronym of "Multimedia broadcast and multicast system". It is already present in 3GPP spec from release 6. But for LTE, it is known as eMBMS. A few number of new nodes and interfaces have been introduced to support eMBMS service like BM-SC (Broadcast and Multicast service center), MBMB gateway, MCE (Multicast/Multicell) coordination entity) etc.
There a term MBSFN(Muliticast broadcast singal frequency network). MCE node which has M2 interface with eNodeBs to make MBSFN area (which will be probably a number of eNodeBs coverage area). All the eNodeB in a MBSFN are should be tightly time synchronized which is job of MCE.
For more details:
check this link:
http://jwcn.eurasipjournals.com/content/2013/1/73
