Research On Routing Protocol For Underwater Acoustic Multi-hop Cooperative Networks

Recently,as the proposing of the policy called"Buliding Maritime Powers",the national strategic position of the ocean increased a lot.The demands are also increasing on marine ecological protection,marine resource development,environmental monitoring,and defense security.Due to its excellent communication performance,the multi-hop cooperative communication networks have a broad development prospects in underwater acoustic networks.The underwater acoustic channel is different from the terrestrial wireless channels due to its long propagation delay,time varying acoustic channels,high channel error rate and limited spectrum frequencies,etc,including the design of the transmitting signals,the processing of the receiving signals,the routing protocols and so on.This paper proposed a parity grouping scheme and the emergency communication scheme combined with end-to-end delay,energy loss,bit error rate performance and average life of the system based on the characteristics of underwater acoustic channel in the underwater acoustic multi-hop cooperative communication networks.Meanwhile,the paper proposed a routing protocol according to the rest energy of the relay nodes to prolong the lifetime of the system.The main contribution of the paper is as follows:1.The researches and literatures in the field of underwater acoustic cooperative networks are summarized including domestic and abroad.We introduce the significant of the method:multi-hop communication and cooperative communication.2.An improved routing protocol was proposed based on multi-hop coordinated transmission for underwater acoustic cooperative networks.The data packets are divided into parity groups and then transferred,where the odd-numbered node transfers the odd-numbered packet and the even-numbered node transfers the even-numbered packet accordingly.Arbitrary node can be a cooperative relay for the adjacent two nodes.In the meanwhile,adopting a proper transfer power,arbitrary two nodes separated by four nodes can deliver data packets to the next node without collision.The simulation result shows that the proposed scheme can reduce the average end-to-end delay and energy consumption with the acceptable outage probability effectively.3.We propose an emergency communication scheme based on multi-hop cooperative transmission,which enables the system to maintain transmission work even if some underwater nodes lose their ability to work normally.The proposed scheme includes two steps:the faulty detection and the emergency communication.It can detect which node is broken down and then its adjacent two nodes will complete the scheduled transmission tasks of the faulty node.Simulation results show that the proposed method can improve the performance of the system effectively.4.In the process of choosing the relay node,the nodes,which are closer to the S-D ligature,have a higher probability to be choosed as the relay node to execute the data forwarding process.Under this condition,the nodes,which are closer to the S-D ligature,are more likely to use out and lose their ability to work,which result in the system lifetime finished untimely.Therefore,in this paper,combined with the priority of the packets and the rest energy of each node,we proposed a routing protocol based on the ant colony algorithm to prolong the lifetime of the system.In addition,through the simulation we can prove that this routing protocol can use the resource of the system preferably.