5G Technology

75G Radio Protocols

Tero Henttonen¹, Jarkko Koskela¹, Benoist Sébire², and Antti Toskala¹

¹Nokia Bell Labs, Finland

²Nokia Bell Labs, Japan

CHAPTER MENU

1. Introduction
2. 5G Radio Protocol Layers
3. SDAP
4. PDCP
5. RLC
6. MAC Layer
7. The RRC Protocol
8. Radio Protocols in RAN Architecture
9. Summary
10. References

7.1 Introduction

The Long‐Term Evolution (LTE) radio protocols were primarily designed for the provision of PS services through a flat architecture. They were a major improvement over the previous generations, eliminating the complexity inherent in the support of circuit‐switched (CS) services and in a convoluted architecture. Many of the original principles of LTE remained untouched since Release 8 and have proved to be a solid baseline for over a decade. Thus, in the early days of 5G standardization, it was agreed to use the LTE radio protocols as a baseline for 5G and to enhance them for the support of very high data rates with low latency, dynamic spectrum usage, and flexible Quality of Service (QoS).

This chapter describes the 5G radio protocols, with a focus on the modifications and enhancements brought to the LTE baseline. Unless otherwise mentioned, it can be assumed that the descriptions apply to both 5G with dual connectivity with LTE toward Evolved Packet Core (EPC) (non‐standalone), and 5G with connection to 5GC (standalone).

7.2 5G Radio Protocol Layers

The 5G radio protocols consist of a user plane (UP) and a control plane (CP). The UP is located between the IP layer and the physical ...