Inter-Slice Traffic Steering Technologies for Beyond 5G Networks

For beyond 5G systems, several key issues related to network slicing are being discussed in the 3rd Generation Partnership Project (3GPP). Among them, the issue of moving traffic from one slice to another slice with minimum service interruptions and quality of experience (QoE) degradations are important but yet to be resolved.To this end, we propose a network architecture where a slice steering function (SSF) is introduced to steer the traffic from one slice to another slice with minimum service interruptions by establishing a new session in the target network slice via which the ongoing traffic can be sent before releasing the session in the source network slice. Also, to minimize the QoE degradation, we propose an optimal scheme for selecting the target UE (i.e., UEs to be moved from one slice to other slices) and the target slice (i.e., TU-TTS), which minimizes the total degraded QoE of target UEs and the control plane signalling for steering by considering application types of UEs and by minimizing the number of target UEs that are to be moved, respectively.The simulation results are shown that TU-TTS reduces the normalized total degraded QoE and the normalized control plane signaling cost by 15.1-18.8% and 2.5-9.1%, respectively when compared to the conventional schemes.