Novel Algorithm for Drastic Reduction of N2 Signalling in 5G and Beyond

Abstract

5G network defined by 3GPP, has two major parts: Core Network (CN) and Radio Access Network (RAN). CN is a set of nodes interconnected to provide service to the user equipment (UE). N2 interface connects RAN node (base station, referred as gNB) to the CN node AMF (Access and Mobility Function). When a CN node is down, the sessions handled by that CN node are affected. The other nodes in CN (referred as Peer CN nodes) are capable to detect the failure and take further actions to clean up and restore the affected sessions. UE will experience service impact until its session clean up and restoration is complete. It is very crucial to restore the sessions quickly, such that the negative influence on the network efficiency is minimized. Clean up and restoration is a long time taking as well as resource heavy process, as a CN node handles millions of sessions and its down impacts all these sessions. We propose a novel session clean up algorithm and new call flows, which restore the sessions within quick time resulting in minimal adverse impact to the network performance there by reducing the service impact to the UE. Our proposed idea addresses the problems of time taken to clean-up the sessions and surge in signaling messages. Extensive simulation results reveal 99% reduction in the total time taken to clean up the sessions when compared to existing standard procedures.