Migration and Interworking between 4G and 5G

The introduction of 5G provides an opportunity for mobile operators to build, integrate, and upgrade existing infrastructure to enrich their existing services and enable new business use cases. Mobile operators want to leverage their existing infrastructures as much as possible so that cost of deploying a new network is optimal and it continues to provide existing services with seamless interworking. The main goal of this paper is to provide system architecture and methods for interworking and migration between 4G and 5G mobile technologies. Some of the key challenges faced in rolling out 5G are: (a) ability to serve 4G, 5G Non-standalone (NSA) and standalone (SA) subscribers, (b) integration of new 5G radio without overloading existing network, (c) enabling 5G devices with new applications and enhanced quality of service (QoS), and (d) introducing network slicing to enrich 5G experience. This paper identifies different interworking scenarios, associated challenges, and addresses possible solutions. In summary, mobile service provider must define their transformation journey based on what 3G/4G network they have, what new services need to be enabled, and then develop 5G architecture with smooth integration.