This chapter introduces the EPS architecture, mainly presenting a high-level perspective of the complete system as defined in the 3GPP SAE work item. In subsequent sections, we introduce the logical nodes and functions in the network. By the end of this chapter, the main parts of the EPS architecture should be understandable and readers will be prepared for the full discussion about each function and interface, as well as all applicable signaling flows that follow in Parts III and IV.
2.1 EPS Architecture
There are several domains in EPS, each one a grouping of logical nodes that interwork to provide a specific set of functions in the network.
A network implementing 3GPP specifications is illustrated in Figure 2.1 ...