Live Video Multicast for Dynamic Users via Segment Routing in 5G Networks

Live video streaming applications are expected to proliferate very rapidly in the next generation network, i.e., 5G networks. To efficiently serve all users watching the same live video in 5G networks, the multicast technique plays an important role in providing scalable and high-performance services. Software-Defined Networking (SDN), contained in 5G networks, further facilitates the development of multicast techniques due to its flexibility of updating routing rules. However, few of conventional multicast mechanisms in SDN take into account the rule update overhead resulting from handovers of mobile users, which leads to tremendous network overhead. In this paper, we adopt Segment Routing (SR) as the first step to alleviate the rule update overhead, and then consider the rule update cost while maintaining the multicast tree to deal with user handovers. Thus, we first formulate Handover-aware Multicast Tree (HMT) problem and then show that HMT is NP-hard and does not admit any approximation algorithm. We then propose a heuristic algorithm called Mobility Aware Multicast Tree Algorithm (MAMTA). MAMTA takes advantage of user movement prediction to assign a base station that could provide longer service to a user, which leads to infrequent rule updates. Simulation results show that MAMTA significantly outperforms the shortest path tree and Steiner tree algorithms.