LTE Medium Access Control (MAC) is a layer 2 protocol and provides data transfer and radio resource allocation services to upper layers. It performs scheduling of the data according to priorities, and multiplexing data to physical layer transport blocks. RRC layer controls configuration of MAC sublayer. In E-UTRA, there are two MAC entities, one in the UE and other one in the eNB.
Earlier, I blogged about E-UTRAN and its interface with LTE core network. Similar to RAN, with 3GPP release 8, core network also evolved and called Evolved Packet Core or “EPC” in short. With LTE, 3GPP has gone away from circuit switched core and has fully aligned with packet core.
With Release 8, 3GPP has introduced a whole new set of protocols as both radio access network and core network have evolved from the earlier 2G & 3G Networks. In LTE architecture, evolved core network includes Mobility Management Entity (MME), Serving Gateway (SGW), Packet Data Network Gateway (PDN GW) where as evolved radio network has only E-UTRAN NodeB (eNB).