With the continuous growth of China’s blue economy,more and more unmanned boat formation clusters are being applied in fields such as marine exploration and resource fishing.However,the existing marine communication networks have low speed and poor stability,and are no longer able to meet the growing communication needs.Therefore,there is an urgent need for a high-speed and highly stable maritime wireless communication network.Wireless ad hoc networks have the characteristics of decentralization,spontaneous organization,and self-healing,making them suitable for quickly laying communication networks and completing various transmission tasks in harsh environments without fixed facilities.Therefore,this project will study wireless ad hoc network communication protocols under maritime channel conditions,propose an adaptive backoff algorithm based on listening mechanism and a cross layer routing protocol based on local topology stability,in order to effectively improve the performance of maritime wireless ad hoc networks.The main job responsibilities are as follows:Firstly,considering that existing backoff algorithms cannot distinguish between packet loss and packet collision in maritime networks,this project proposes an adaptive logarithmic backoff algorithm based on channel monitoring.This algorithm models the transmission process of wireless ad hoc networks,summarizes and summarizes the mathematical relationship between the optimal competition window and the number of competing nodes,evaluates the number of competing nodes in the network through a listening mechanism,and dynamically adjusts the competition window to ensure the maximum probability of nodes successfully accessing the channel.This algorithm helps to improve the throughput and fairness of the entire network,reduce end-to-end latency and packet loss rate.Then,in response to the problem that existing routing protocols cannot adapt to the dynamic changes in transmission losses in offshore channels,this project proposes an improved cross layer AODV routing protocol based on local topology stability index.This protocol comprehensively considers the dynamic changes of maritime channels and the mobility characteristics of nodes,proposes the concept of local topology stability,obtains and evaluates the changes in local topology through the MAC layer,and finds the most stable path between the source node and the destination node to transmit data packets;At the same time,the protocol also accelerates the acquisition of network topology changes and the recovery and reconstruction of faulty networks through dynamic update mechanisms and routing maintenance mechanisms.This protocol helps to improve throughput,reduce packet loss rate,end-to-end latency,and routing overhead.Finally,this project utilized OMNe T++simulation software and the INET open-source framework to build a simulation model for offshore wireless ad hoc networks.Through simulation experiments,the effectiveness of the proposed innovation was verified.The simulation results show that the optimization algorithm and improved protocol proposed in this project exhibit better and stable performance in marine environments,and have high engineering application value,providing new feasible solutions and solutions for improving the performance of marine communication networks. |