A New User-Centric Opportunistic Handover for LEO Satellite Communication Systems

With the rapid increase in the number of users, user-centric handover research has attracted extensive attention for low Earth orbit (LEO) satellite communication (SatCom) systems. However, in densely populated areas, a large number of users may access a certain satellite, leading to severe bottlenecks as the users independently select a target satellite for handover. To address this issue, we propose a new user-centric opportunistic handover (OHO) scheme that leverages randomness to enable efficient channel resource utilization and mitigate bottlenecks. Specifically, each user calculates the probabilities derived from the transmission rate and the number of available channels of visible satellites and then selects a target satellite for handover based on these probabilities. The proposed OHO scheme effectively addresses bottleneck issues by allowing the users to connect to various satellites rather than a certain one. Simulation results demonstrate that the proposed OHO scheme outperforms the conventional user-centric handover schemes in terms of the average number of handovers, the average blocking rate, and the average throughput as the number of users increases.