We have now completed our discussion of the LTE air interface. In the course of the next seven chapters, we will cover the signalling procedures that govern the high-level operation of LTE.
In this chapter, we describe the procedures that a mobile follows after it switches on, to select a cell and register its location with the network. We begin by reviewing the procedure at a high level and then continue with the three main steps of network and cell selection, RRC connection establishment and registration with the evolved packet core. A final section describes the detach procedure, through which the mobile switches off. As part of the chapter, we will refer to several of the low-level procedures that we have already encountered, notably the ones for cell acquisition and random access.
Network and cell selection are covered by two specifications, which describe the idle mode procedures for the non-access stratum  and the access stratum . The signalling procedures in the rest of the chapter are summarized by the usual stage 2 specifications for LTE [3, 4]. Readers who require more detail about these procedures can find it by digging down into the relevant stage 3 signalling specifications [5–9], which define both the procedures on each individual interface and the contents of every signalling message.
Figure 11.1 summarizes the procedures that the mobile follows after it switches on. The mobile begins by ...