Research And Improvement Of Routing Algorithm In Underwater Acoustic Sensor Networks

As a new breed of networking technique,underwater acoustic networks are derivative networks of wireless sensor networks.Underwater acoustic sensors are usually deployed in the designated area to the bottom,the surface or the water in the shallow sea.Sensor nodes self-organize network through the communication protocol set in advance.Underwater acoustic networks have enabled quantities of military,environmental,scientific and commercial applications,such as offshore exploration,military surveillance,oceanographic data collection,disaster warning.However,the environment of underwater complex communication brings new challenges to the sensor network technology.The propagation speed of sound in the underwater environment is very low.Long propagation delay between transactions will reduce the throughput of networks.Underwater acoustic bandwidth available becomes extremely limited.It in turn results in a very low bit rate.Also,underwater acoustic communication is mostly effected by path loss,multi-path and Doppler spread.Thus it is because of these harsh characteristics of underwater channel that mature communication protocols cannot be directly applied to underwater acoustic networks at the present stage.In this paper,the following research work is carried out:First of all,routing protocol plays an extremely important role in guiding the packets to arrive the destination in underwater acoustic communication.After analyzing and studying various routing algorithms for mobile ad hoc networks,the advantages of AODV protocol in underwater sensor networks are demonstrated.To a certain extent,AODV is more suitable for underwater acoustic networks than other routing protocols.Secondly,Underwater sensor network,self-organizing network,has no center nodes and non-measurable network topologies.Affected by the acoustic channel transmission bandwidth,link capacity constraints and other factors,the performance of AODV protocol will greatly decrease.The edge effect is easy to appear in the large density of nodes,there are high packet loss rate and short survival period of routing problems.Modeling of the wireless transmission range of sensor nodes,this paper proposes an improved LS-AODV algorithm based on link stability.Once more,the original AODV algorithm is improved in the process of the repair process,and the life cycle of the effective link is optimized.The new complementary strategies are conducive to rapidly repair upstream node at fracture,which can reduce the network congestion and reduce the delay in the network.The new RE-AODV algorithm is suitable for underwater sensor networks.Finally,the performance of the original algorithm and the improved algorithm are discussed through the OMNET++ simulation network experiment.The LS-AODV algorithm in packet delivery rate,throughput and end-to-end delay is better than the traditional AODV protocol;RE-AODV algorithm in packet delivery rate,route setup time and end-to-end delay is also effectively enhanced.