A Distributed Survivable Routing Algorithm for Mega-Constellations With Inclined Orbits

Abstract

Mega-constellations consisting of hundreds to thousands of low-earth-orbit (LEO) satellites are an attractive solution for providing global ubiquitous network access. Due to good coverage properties for populated areas, inclined orbits are gaining popularity among commercial constellations. A scalable routing algorithm with survivability plays a key role in such systems. In this paper, we propose a distributed survivable routing algorithm for mega-constellations with inclined orbits. First, the special topology characteristic of inclined constellations is identified and formalized. Based on the topology characterization, a basic X-Y routing algorithm is presented to determine multiple primary and secondary paths towards each destination utilizing the regularity of the network topology with minimal computation overhead. Then, a failure recovery mechanism which consists of a restricted flooding mechanism and a pre-detour mechanism is proposed to reduce end-to-end delay and signaling overhead in case of link failures. Besides, a partialrecord loop avoidance mechanism is proposed to deal with routing loops with minimal overhead. Finally, a vector-based next hop selection mechanism is proposed to facilitate the selection of next hop while incorporating various criteria. The performance of the proposed routing algorithm is evaluated through simulation on the Starlink constellation. Simulation results show that our proposal achieves scalability by reducing signaling overhead and provides better quality of service in terms of end-to-end delay under link failures.

Task-Aware Distributed Inter-Layer Topology Optimization Method in Resource-Limited LEO-LEO Satellite Networks

“…In this network, RLSs can collect observation data and transmit data to CLSs by inter-layer laser links. Then, CLSs route data to ground stations through intra-layer links and satellite-earth links with routing algorithms proposed in [14]- [16]. CLSs consist of many small satellites and can cover all RLSs so that ground stations can get observation data in real-time.…”

Distributed Probabilistic Congestion Control in LEO Satellite Networks

“…The phenomenon of congestion along higher latitude horizontal directions is something that is addressed in the probabilistic load balancing part of the congestion control algorithm proposed. Qi et al [22] focuses on performing distributed routing in constellations where the satellites are in inclined orbits (as opposed to polar orbits). Inclined orbits do not pass over the poles, and thus, inter plane ISLs do not need to be switched off, which makes this constellation have a nearconstant topology.…”

Task-Aware Distributed Inter-Layer Topology Optimization Method in Resource-Limited LEO-LEO Satellite Networks

“…The first aspect focuses on single-layered satellite networks where data transmission is implemented through intra-layer links. Many researches [14]- [16] studied the routing algorithms in single-layered mega-constellations with inclined/polar orbits, and they applied a fixed network topology. As for unfixed topology, Yan et al [17], [18] proposed a link allocation strategy to maximize throughput from non-anchor satellites to anchor satellites, where anchor satellites are those connected to ground stations, and non-anchor are the opposite.…”

“…However, these studies [14]- [19] do not reflect functional differences in satellites, which means remote-sensing satellites are also responsible for routing data back to earth. These approaches may be efficient in small-scale systems but may result in congestion and low efficiency in mega constellations consisting of various types of satellites.…”