Improvements of AODV Routing Protocol in Shipborne Ad-Hoc Networks

In maritime environments where ships aim to establish ad-hoc networks for communication, the constantly moving ship nodes cause the network status to oscillate between mobile ad-hoc networks (MANETs) and opportunistic networks. Different connected sub-domains may form among the ships, and there may not always be a complete communication path between the source and destination nodes. Utilizing the AODV protocol under these circumstances can lead to frequent route discoveries and generate redundant information in the network, thereby degrading communication quality. To address this issue, this paper proposes improvements to the AODV routing protocol and innovatively proposes a method for determining the network state. Upon identifying an opportunistic network state, it introduces a strategy for defining an effective relay candidate area, considering the direction of ship nodes. This approach facilitates the selection of candidate nodes that clearly meet the criteria. The optimal next-hop communication node is then determined based on its Euclidean distance to the destination node. Simulation results confirm that the improved AODV protocol effectively enhances the overall communication quality in mixed shipborne ad-hoc networks.