Initial Access, RRC and Mobility

Book chapter, 2018

In the 3rd generation partnership project (3GPP), the control plane (CP) functions related to radio-specific functionality are standardized in the form of the radio resource control (RRC) protocol. This chapter covers the CP procedures for the access of a user equipment (UE) to the network. It covers the initial access, including the transmission of system information, optimized Random Access CHannel (RACH) access, and various enablers for initial access in the context of beam-based connectivity. It then describes the fundamentals of user equipment (UE) state handling and why 5th generation (5G) requires a new state to support better battery savings and faster setup for data transmissions. The chapter also covers mobility, discussing both normal handover (HO) with enhancements, and mobility in the context of multi-connectivity. It explores how to handle beamforming and mobility.