This chapter contains a brief overview of the overall architecture of an LTE radio-access network and the associated core network, followed by descriptions of the radio-access network user-plane and control-plane protocols.
8.1 Overall System Architecture
In parallel to the work on the LTE radio-access technology in 3GPP, the overall system architecture of both the Radio-Access Network (RAN) and the Core Network (CN) was revisited, including the split of functionality between the two network parts. This work was known as the System Architecture Evolution (SAE) and resulted in a flat RAN architecture, as well as a new core network architecture referred to as the Evolved Packet Core (EPC). Together, the LTE RAN ...