QoSRA: A QoS-Aware Routing Algorithm for Software Defined Satellite Networks

Satellite networks are moving in the direction of merging with terrestrial networks, thus more types of services will flood into satellite networks. To meet the QoS requirements of different communication services in satellite networks, it is necessary to design effective on-board routing algorithms. In this paper, we design an SDN-enabled LEO/GEO satellite network model at first. In view of this model, a QoS-aware routing algorithm (QoSRA) based on the traffic scheduling framework combining Priority Queue (PQ) and Weighted Round Robin (WRR) is proposed. QoSRA divides the services in satellite networks into three categories: class A (two-way conversational services), class B (request-response services) and class C (one-way data streaming services), so as to provide differentiated services for these different types of services. For class A and class B services which both have certain requirements for delay, we improve the low-complexity routing algorithm (LCRA) to obtain the optimal path with the location information of the current satellite node and the destination node by centralized computation. For class C services that have high restrictions on bandwidth, we propose a dynamic bandwidth adaption algorithm based on link status, which provides the bandwidth guarantee for these services while solving the congestion problem on the shortest path. Through the comparison of simulation, QoSRA can not only guarantee the QoS requirements of different types of services but also is superior to other routing algorithms in terms of mean end-to-end delay, packet loss rate and data throughput.