Research On Pressure Sensing Routing Protocol For Underwater Sensor Networks

Underwater sensor networks play an increasingly important role in marine exploration applications,such as in marine monitoring,pollution detection,and marine resource management.The routing protocol guarantees the reliability and validity of data transmission from the source node to the destination node,so the routing protocol occupies a more important position in the underwater sensor network.The geographical location information of the sensor node is difficult to obtain,because the GPS(Global Positioning System)signal is attenuated in the ocean.The underwater acoustic routing protocol based on depth information is to obtain the depth information of the node by carrying a water pressure sensor to the underwater sensor node,and the route is simplified from three-dimensions to two-dimensions.The operating principle is that the sensor node compares its own depth with the depth of the previous hop node,so as to determine whether it has the right to forward the data packet.However,the protocol has problems such as high energy consumption,routing holes,and redundant data packets.Therefore,this topic is mainly aimed at improving protocol based on the depth underwater acoustic routing.Firstly,this thesis proposes a method for optimizing the priority and waiting delay function of a node in a deep routing protocol.The priority of a node is determined by the remaining energy of the node,the estimated hop count and the communication capability.The more the remaining energy of the node,the higher its priority,and the more likely it is to become the next hop forwarding node.It effectively avoids the node with the shallowest depth in the local area participating in forwarding the data packet multiple times and causing energy.The problem of early consumption;the estimated hop count reflects the reachability of the link,the node with small hop count has higher priority,effectively avoids the routing hole and the problem of "seek far and neglect what lies close at hand ";the communication capability of the node refers to the workload and work efficiency of the node in the network.The algorithm effectively balances the workload in the network by selecting the node with the current workload and high transmission efficiency as the next hop node.The thesis also puts forward an algorithm based on AUV(Autonomous Underwater Vehicle)node recovery mechanism.The algorithm is to solve the routing hole problem.The algorithm firstly obtains the key node set of the underwater sensor network,and then the node estimates the approximate time of entering the sleep state according to its residual energy and historical energy consumption rate,and is about to enter sleep.When the status is notified to the AUV,the AUV moves to the vicinity of the sleep node location,again restores network connectivity and extends the network life cycle.In this thesis,the network simulator NS-3 is used to simulate the above two improved algorithms.The simulation results show that the first improved protocol can effectively reduce the number of redundant packets,improve the packet delivery rate and reduce the average end-to-end delay.The second improved algorithm can effectively solve the problem of routing holes in deep routing protocols,improve the network connectivity and prolong the network life cycle.