S12:- Reference point between UTRAN and Serving GW for user plane tunnelling when Direct Tunnel is established. It is based on the Iu-u/Gn-u reference point using the GTP-U protocol as defined between SGSN and UTRAN or respectively between SGSN and GGSN. Usage of S12 is an operator configuration option.
In a simple words "reference point between SGW of LTE and RNC of UMTS" known as S12. It is optional since data plane can be passed through S4 interface. S4 interface exists between SGW and SGSN.
I came to know total six subframes of a radio frame can be used for MBSFN transmission. How UE come to know about exact number of sub frames that are being used in a radio frame ? Does the eNodeB send this information to UE or UE itself figure out ?
Here two scenarios are possible: - First scenario, target eNodeB and source eNodeB both have connection with same MME - Second scenario, when both the eNodeBs are connected to different MMEs ?
