ABSTRACT
System architecture evolution and long-term evolution, also named as evolved packet system (EPS) and standardized by Third Generation Partnership Project (3GPP) is already seeing worldwide deployment. EPS standardization activity took off with the objectives to come up with a system with higher data rate, lower latency, enhanced quality of service and high level of security. This chapter provides an overview of EPS system with an overview of the architecture by explaining about different network elements, protocol layers, and different states. It explains the initial network attachment or registration of a user equipment to the network. The chapter discusses the input parameters for confidentiality and integrity protection. Key change on-the-fly was developed in 3GPP to allow change in key when different security context needs to be activated. During handover, service continuity without perception of service quality degradation by the user is the most important point.
