A Graph-Based Satellite Handover Framework for LEO Satellite Communication Networks

This letter proposes a graph-based satellite handover framework for the low earth orbit (LEO) satellite communication networks. In order to maintain the connection with the communicating counterpart, the user has to switch between consecutive satellites covering the very user. A directed graph with covering period of the satellite as its node, and the link representing the possible handover between two overlapping periods, is calculated in advance, and then, the satellite handover process can be viewed as finding a path in the directed graph. By setting the link weight according to different handover criterions, the graph-based framework can support a variety of satellite handover strategies, which shows the improved flexibility over the existing research. The application of the framework to find the shortest handover path conducted on two typical LEO satellite networks, viz., Iridium and Globalstar, also corroborates the effectiveness of the proposed handover framework.