Chapter 1 - 5G Network Architecture

Abstract

5G network architecture has been designed to support fast and reliable connectivity as well as diverse applications and services, enabling flexible deployments using new concepts such as network function (NF) virtualization, software-defined networking, and network slicing. The 5G system supports a service-oriented architecture with modularized network services. The service-oriented 5G core network is built on the premise that 5G systems must support wide range of services with different characteristics and performance requirements. The service-oriented architecture and interfaces in the 5G systems make the future networks flexible, customizable, and scalable. Network service providers can leverage service-oriented architecture design in 5G to manage and adapt the network capabilities, for example, by dynamically discovering, adding, and updating network services while preserving performance and backward compatibility. The main difference in the service-based architecture is in the control plane where, instead of predefined interfaces between entities, a service model is used in which components request a new network entity to discover and communicate with each other over application programming interfaces. It is also important for the 5G network to enable each NF to directly interact with other NFs. It is also desirable to minimize dependencies between the access network and the core network. To further support multi-RAT access, the network architecture was required to provision a unified authentication framework. The support of stateless NFs, where the compute resource elements are decoupled from the storage resource elements, creates a disaggregated architecture. To support low-latency services and access to local data networks, the user-plane functions can be deployed close to the edge of the access network which further requires support of capability exposure and concurrent access to local and centralized services.