A Greedy Routing Protocol Based on a Stable Relay Algorithm for UAV Ad Hoc Networks

In Unmanned Aerial Vehicle (UAV) ad hoc networks, nodes move at a high speed, leading to a low communication success rate. Therefore, communication between UAV nodes requires specific routing protocols. Many researchers have improved traditional routing protocols by enhancing the quality of the one-hop link and handling the routing void. However, since they only took into account the one-hop link between the source node and the one-hop neighbor node, the improvement was not significant. In order to reduce the packet loss rate and improve the throughput, this paper proposes a greedy routing protocol based on the stable relay algorithm (GRPBSR). In GRPBSR, there are two modes for nodes to transfer data packets: the stable forwarding mode and the routing void forwarding mode. In the stable forwarding mode, the source node selects relay nodes based on the stable relay algorithm which takes into account the distance between the one-hop neighbor node and the destination node, the stability of the link between the source node and the one-hop neighbor node, as well as the quality of the link between the one-hop and the two-hop neighbor node. In routing void forwarding mode, the source node divides the routing void into five cases and assigns corresponding solutions to each of them based on the integrated link and the fine-tuned stable relay algorithm. Through analysis and comparison, the results show that the performance of GRPBSR is superior to other routing protocols.