PHandover: Parallel Handover in Mobile Satellite Network

The construction of Low Earth Orbit satellite constellations has recently spurred tremendous attention from both academia and industry. 5G and 6G standards have specified the LEO satellite network as a key component of the mobile network. However, due to the satellites’ fast traveling speed, ground terminals usually experience frequent and high-latency handover, which significantly deteriorates the performance of latency-sensitive applications. To address this challenge, we propose a parallel handover mechanism for the mobile satellite network which can considerably reduce the handover latency. The main idea is to use plan-based handovers instead of measurement-based handovers to avoid interactions between the access and core networks, hence eliminating the significant time overhead in the traditional handover procedure. Specifically, we introduce a novel network function named Satellite Synchronized Function (SSF), which is designed for being compliant with the standard 5G core network. Moreover, we propose a machine learning model for signal strength prediction, coupled with an efficient handover scheduling algorithm. We have conducted extensive experiments and results demonstrate that our proposed handover scheme can considerably reduce the handover latency by 21× compared to the standard NTN handover scheme and two other existing handover schemes, along with significant improvements in network stability and user-level performance.