Handover schemes in satellite networks: state-of-the-art and future research directions

Abstract — Low Earth Orbit (LEO) satellites will work as an important component in future data communication networks. LEO satellites provide low end-to-end delays and efficient fre-quency spectrum utilization, making it suitable for personal communication. However, due to high satellite speed, the ongoing communication using LEO constellations experiences frequent handover. In this paper, we provide an up-to-date comprehensive literature survey on proposed handover schemes for LEO satellite systems. We also present a detailed classification of handover schemes based on a common framework. We first classify the schemes into link layer and network layer handover schemes. Link layer handover schemes are further classified into three categories: (a) spotbeam handover schemes, (b) satellite handover schemes, and (c) ISL handover schemes. Spotbeam handover schemes are categorized based on channel capacity, handover guarantee, and handover prioritization techniques. Network layer handover schemes are also classified depending on connection transfer strategies. Finally, we compare the handover schemes using different Quality of Service. I.