5G Inter-RAT Network Slicing Handover Mechanism: A Systematic Review

Network slicing is a virtual network that has the capabilities to provides different logical segment based on different classes of services based on the three used cases in 5G network that released by 3GPP Rel 16 which are Enhanced Mobile Broadband (eMBB), Ultra Reliable and Low Latency Communication (URLLC) and Massive Machine Type Communication (mMTC). During the handover between different RATs occurred (Inter-RAT) in 5G NR heterogeneous environment, the process for UE allocation to the right network slice should be handle in a manner way to maintain the performance from the previous network slice. This paper aims to review the Inter-RAT handover mechanism approach for network slice selection in 5G environment. Review process will investigate the handover procedure works, then we will go through the mathematical theories used for modelling the network slice selection mechanism for Inter-RAT handover. Lastly, we will compare the theories and discuss the benefits in term of optimization and performance based on the selected criteria. With the purpose of limiting our scope to our main goal, we considered only papers published in conferences and journals between 2011 and 2020. A selected paper must discuss the network slicing Inter-RAT handover mechanism in dealing with a 5G technological issue. We will focus on works included only Inter-RAT handover in 5G, the handover procedure, selected criteria and mathematical theories used for optimization and performance in network slicing. The findings that will be discuss in this paper is the mathematical theories used in modelling the network slice selection mechanism during Inter-RAT handover by focusing on optimization and performance based on the selected criteria in 5G NR heterogeneous environment. This paper will contribute the systematic review around network slice selection mechanism during Inter-RAT handover.