Fast Recovery from Multiple Link Failures in LEO Satellite Networks

This paper introduces a protection mechanism for complete recovery from multi-link failures in Low Earth Orbit (LEO) satellite networks. Inter-satellite links (ISLs) may break down frequently due to the interruption of wireless channels, the high-speed movement of satellites and the long distance for communication. As a proactive scheme for recovery, IP Fast Reroute (IPFRR) has been used to achieve fast rerouting via pre-calculating backup paths. Although IPFRR has effectively addressed the problem of single-link failures, the recovery from multi-link failures still needs further studies, especially on aspects such as recovery rate, computation complexity and storage cost. For better survivability of LEO satellite networks, we develop an IPFRR mechanism for recovering from multi-link failures. This new mechanism, called Grid Bypass Routing (GBR), assigns two addresses to every network device - a normal address and a protection address. When failures occur, routers will choose the protection address to deliver packets via alternative paths. We develop a technique to compute backup paths and prove that GBR can guarantee complete recovery. We evaluate GBR in the simulation, and the result shows that the advantage of its computational cost, forwarding table size and recovery rate makes GBR a more efficient and easily manageable IPFRR solution to link failures in LEO satellite networks.