5G-Flow: A unified Multi-RAT RAN architecture for beyond 5G networks

Convergence of multiple access technologies is one of the key enablers in providing diverse set of services to the Fifth Generation (5G) users. Though 3rd Generation Partnership Project (3GPP) 5G standard defines a common core supporting multiple Radio Access Technologies (RATs), Radio Access Network (RAN) level decisions are taken separately across individual RATs as the existing 5G architecture lacks a unified control and management framework for a multi-RAT network. A unified access network is likely to utilize RAN resources more efficiently and provide an improved performance. In order to achieve a unified Multi-RAT RAN, we supplement the existing 3GPP 5G RAN architecture with OpenFlow. We refer to the proposed architecture as 5G-Flow. The proposed architecture can be viewed as a step towards further evolution of mobile networks beyond 5G. With minimal changes in the 3GPP 5G RAN and none in the core network, we are able to realize a unified and integrated multi-access 5G-Flow RAN. We simplify the existing 5G RAN by replacing RAN nodes with OpenFlow switches and a software-defined controller. The proposed architecture also allows us to completely decouple User Equipment's (UE's) communication with Core Network (CN) from its communication with RAN enabling a UE to use any RAT to connect to any CN (say, use 5G New Radio access to connect to 4G CN, which is not possible in the 3GPP architecture) or to directly connect to Internet from RAN without going via the CN. We have developed an evaluation platform to compare the performance of our proposal with the standard 3GPP architecture. Results demonstrate significant gains in the network performance of 5G-Flow RAN over the existing 3GPP 5G network.