Study Of Reliable MAC Layer Strategy In Underwater Acoustic Sensor Network

Underwater acoustic sensor network is a useful tool in exploring and utilizing marine resources.Compared with terrestrial wireless communication,nodes in underwater acoustic network use acoustic wave to communicate,leading to many challenges in building a reliable network.Specifically,in single-channel acoustic network,time-spatial uncertainty influences the communication quality severely.In multiple-channel acoustic network,malicious nodes in the network may have negative effects on channel allocation.These problems limit the development of acoustic network.Reasonable and effective resolutions are needed desperately.Based on the application and device situation,this paper researches two reliable MAC layer strategies.In single-channel underwater acoustic network,a new protocol named PC-MAC is proposed.In PC-MAC,in order to ensure the successful transmission,the receiving node takes the time-spatial uncertainty into consideration and makes a receiving window for each packet.PC-MAC is effective in avoiding the collisions.In multiple-channel acoustic network,a new channel allocation algorithm is proposed.The new algorithm aims to getting the maximum communication capacity and increasing the accessing fairness.The central node uses the Hungarian Method to get the best allocation result,which is collision-free and has the maximum communication capacity.Fairness function is applied to avoid the influence of malicious nodes.Simulations are conducted in this paper to verify these two MAC layer strategies.NS-2 simulations show that PC-MAC can achieve better performances by adjusting the parameters to network traffic.PC-MAC also has smaller collision probability than Slotted-FAMA.MATLAB simulations prove that using Hungarian Method to get the channel allocation result can avoid the collision between sending and receiving node pairs.Communication capacity is increased as well.Fairness functions is effective in prevent malicious nodes from occupying a channel for a long time.Among different fairness functions,negative exponential function has better performances.