5G Architecture

This chapter presents an overview of the different 5G architectures and then covers in more details the radio access network (RAN) architecture and interfaces as well as the 5G Core (5GC) network with key elements and functionalities. Originally there were eight architecture options on the table in 3GPP discussions when all possible aggregation and core network combinations were considered, but as the work progressed the following two main architecture options emerged, with slight difference in timing. First in the finalization schedule was the approach with Long‐Term Evolution (LTE) as the connection anchor and using the existing LTE core, with 5G radio as the secondary cell (Architecture option 3). Next to be completed was the standalone 5G radio with the new 5G core (architecture option 2). This chapter also presents an introduction of network slicing support in Release 15. With slicing, it is possible to consider the customers needing different level of service.