Standards, Protocols, and Functions

This introductory chapter explains the basic network functions, signaling procedures, network architecture, protocols, and standards used in the Long-Term Evolution (LTE) network. Compared to base stations in GSM and universal mobile telecommunications service (UMTS) universal terrestrial radio access network (UTRAN), the eNB will cover a set of new functions that are crucial to understand how the evolved-UTRAN (E-UTRAN) is working. In addition, the functionality of the mobility management entity (MME) and S-GW is different from that of their 2G/3G relatives, the RNC and the SGSN. This chapter presents a list of logical meta-functions performed within the overall network/system was defined by 3GPP. These meta-functions are found in the different network elements with a more specific functionality definition. As in UMTS, the LTE mobile station is called User Equipment (UE). It is constructed using a modular architecture that consists of three main components: mobile termination, terminal adapter, and terminal equipment.