Simple Change Adaptive Routing Algorithm for Satellite IP Networks

although the LEO constellation has dynamic satellite network topology, the topology changes are predictable and periodic. Based on the characteristics above, a new simple change adaptive routing algorithm (SCARA) is proposed for satellite IP networks. SCARA uses simple rules to decide the next hop. The rules are 1) using only two possible directions to reduce the routing path; 2) assigning higher priority to the direction with higher satellite latitude; 3) avoiding the polar region;4) avoiding congestion with local buffer and queue information. SCARA is a kind of distributed routing algorithm. Only local information, such as satellite latitude, logical location, buffer, source and destination address, etc., is needed to route packets, and information from other satellites is not necessary for routing. This feature makes SCARA can be used in satellite IP networks. A simulator is developed for evaluating the performance. The simulation result shows that SCARA has the capability to find the minimum path, lower end-to-end delay and lower time complexity.