A QoS Guaranteed Efficient Integration of UPF and LEO Satellite Networks

Integrating the User Plane Function (UPF), which is responsible for forwarding user data in 5G, with the Low Earth Orbit (LEO) satellite networks can facilitate communication among users and take advantage of satellite edge computing. Satellite UPF (S-UPF) placement strategy is crucial to the integration performance. Static placement, in which the S-UPF drifts away with the satellite, is difficult to adapt to the dynamic satellite networks. The uneven distribution of terrestrial traffic and the resource limitations of satellites cause overload. The fast movement of S-UPF results in an augmented distance between S-UPF and users. The overload and extended distance degrade the Quality of Service (QoS). Dynamic S-UPF placement on satellites is a potential solution, but little attention is paid to it. To fill the gap, we propose a novel approach called Static Assignment Dynamic Placement (SADP), which comprises two key components: static user assignment and dynamic S-UPF placement. Static user assignment is designed to prevent overload, and dynamic S-UPF placement is applied to overcome the QoS degradation due to the extended distance between S-UPF and user. We evaluate the performance of SADP using real satellite constellations, and experimental results demonstrate its effectiveness in reducing latency and energy consumption. Compared to the static deployment, SADP achieves a significant 69.1% latency reduction and lower energy consumption. In contrast to deploying S-UPF on all satellites, SADP significantly reduces energy consumption by 85.2% while maintaining comparable latency performance.