LTE is all-IP advanced core architecture proposed in release 8 of 3GPP to only process packets.
The core is named as Evolved Packet Core (EPC). The primary goals of this architecture was to achieve higher data rates, low latency, with support for multiple radio access techniques.
The technology is developed to support enhanced media centric services with highest level of QoE (Quality of Experience).
High performance is a result of highly efficient and separate data and control paths and a flat IP core. The flattened out IP architect allows less number of software layers to traverse to process data. The EPC is evolved around new architectures of Mobility Management Entity (MME), Serving System (S) Architecture (A) Evolution (E) Gateway or Serving Gateway SGW, Packet Data Network (PDN) SAE Gateway and Enhanced Packet Data Gateway (ePDG). Figure below shows the architecture of Evolved Packet Core or EPC.