A SDN-Based Dynamic Routing for Multi-UAV Network Based on Bidirectional A-Star Algorithm

The network of unmanned aerial vehicles (UAVs) is the key to realize the coordination of multi-UAV system, and the routing strategy greatly affects the performance of the inter-UAV network. The routing of multi-UAV system has the characteristics of diverse routing performance requirements, strong time-varying environment, and strong node mobility. Therefore, in the face of the above characteristics, we propose an algorithm of dynamic routing for the multi-UAV network based on software defined network(SDN) arichtecure. We have made the following contributions. Firstly, according to the diversity of performance requirements of multi-UAV system, the received signal strength indicator (RSSI) and the minimum hop count are selected as the evaluation indicators of link cost to ensure the reliability of routing links. Secondly, the link cost is expressed as an interval value to describe the variation of the link cost due to the time-vary environment, and an acceptability index is introduced to describe the quality of the link. Finally, an improved bidirectional A-star algorthim is proposed to speed up the algorithm operation and reduce the time to find the optimal routing. The effectiveness of the proposed bidirectional A-star algorithm is validated through numerical experiments.