Research On Localization Algorithms And Routing Technology For Underwater Sensor Network

The 21st century has opened a new era for the full exploitation and utilization of marine resources by mankind.As a newborn wireless sensor network,the Underwater Wireless Sensor Network(UWSN)offers a brand-new way for human to explore the underwater world,which is unknown to mankind,and to discover more underwater resources.It has broad application prospects in many fields such as underwater environment monitoring,auxiliary navigation and tsunami warning.Nowadays,it has gradually become a research focus of researchers all over the world.The research of underwater sensor networks mainly includes underwater acoustic channels,network positioning,topology control and routing transfer.However,due to the intricate underwater environment,underwater acoustic channels have characteristics of long delay,low bandwidth and Doppler effect.Compared with traditional terrestrial networks,underwater sensor networks are facing more challenges.This paper mainly studies underwater sensor network nodes positioning and routing transfer.The research and major contributions of this paper are as follows:Firstly,in terms of positioning underwater sensor network nodes,on the basis of a top-down node positioning strategy,it has put forward a UWSN top-down improved program taking flip ambiguity into consideration,since the previous positioning program did not consider positioning ambiguity,especially the influence of flip ambiguity on the positioning error,in whole positioning process.Firstly,it analyzes how to choose anchor node subgraph in positioning so as to minimize the possibility of flip ambiguity.The method of measuring this possibility is proposed,as well as the anchor node selection strategy to make the least possibility of flip ambiguity in locating unknown nodes.Two improved positioning schemes are proposed with detailed scheme design,and selected according to whether to adopt anchor node proposed.The scheme design mainly includes three parts.They are position estimation with known node depths,confidence factors with improved definition,and estimating results with gradient positioning method.Among them,the second part considers positioning estimation error and the impact of flip ambiguity on the actual positioning error.The simulation results show that the proposed schemes can effectively reduce networks'average location error,guarantee network's high positioning rate and improve network's positioning performance overall.In addition,in the research of underwater sensor network routing,this paper proposes a routing protocol for underwater sensor networks that can provide location services,Position-based Underwater Opportunistic Routing,PUOR.The protocol combines Opportunistic Void Avoidance Routing,OVAR protocol's design ideas,adopts opportunistic routing design to improve network reliability and network throughput.The protocol uses the beacon mechanism to obtain the information of the destination node and neighboring nodes so as to select candidates forwarding set.When solving the candidate forwarding set of the protocol,we can also solve problems related to hidden nodes and holes.As the weight distribution coefficient of OVAR protocol's energy consumption-reliability measure is not flexible,being unable to adapt to the dynamic change of underwater sensor network topology,this protocol uses the characteristic that network assumed target nodes or surface ship nodes can collect underwater nodes'information,proposes a internet-based weight distribution program of energy consumption-reliability,and elaborates the theoretical basis of weight ratio scheme,algorithm implementation,program feasibility and simulation verification analysis.Based on Aqua-Sim simulation platform,a large number of simulation are made on PUOR protocol.The results show that PUOR can effectively improve packet delivery rate,and reduce end-to-end delay and energy consumption of network routing.Compared with OVAR,the PUOR protocol's internet energy consumption-reliability trade-off is can better adapt to the dynamic changes of network topology,thus enhancing the network scalability.