Research On Task-Oriented Underwater Sensor Network Protocol Based On Depth And Vector

Underwater sensor networks are widely used in marine environment monitoring,pollution monitoring,marine resources exploration and other aspects,usually need to deal with emergency tasks and long-term observation tasks.The urgent task network needs to ensure the real-time of data,and has a high requirement for propagation delay.The observation task network needs to ensure the quality,quantity and stability of data,and has high requirements for transmission success rate and energy consumption.Task-oriented underwater sensor networks are composed of a large number of underwater nodes randomly deployed in the monitoring area and sink nodes on the surface.Because of the complexity of underwater acoustic communication and the limited energy of nodes,how to design network protocols according to the underwater environment and achieve the mission objectives is the focus of the work.In order to solve the challenge of task-oriented underwater sensor network protocol design and meet the requirements of different mission objectives for network performance.Firstly,DVBR-Broadcast protocol((Depth and Vector Based Routing Protocol)is proposed in the network layer.The routing decision is made according to the depth of the node and the vector between the nodes.The data packet is transmitted along the path with the best position,and the cost of route discovery is very low.The transmit queue and depth threshold function can reduce collisions and redundant forwarding to some extent.The simulation results show that the transmission success rate of DVBR-Broadcast is 3.25% higher than that of DBR-Broadcast on average,and9%～18% lower than its end-to-end propagation delay.Compared with FloodingBroadcast,the transmission success rate of DVBR-Broadcast is 13.5% higher on average,62% lower than its energy consumption,and 26.5% lower than its end-to-end propagation delay.DVBR-Broadcast improves transmission success rate,end-to-end delay and energy consumption,and its advantages do not decrease with the change of packet length and depth threshold.DVBR-Broadcast can meet the network performance requirements of urgent tasks.However,packet size and depth thresholds have an impact on its performance.Simulation results show that the energy consumption of DVBR increases by 21% and the end-to-end delay increases by 50%when the number of packets increases from 200 bytes to 400 bytes.When the depth threshold is increased to 400,the success rate is reduced by 2.3% and the energy consumption is reduced by 17%.It can be seen that shorter packets and appropriate depth threshold can make its performance more stable.Secondly,in order to deal with the long-term stable and reliable observation task,this paper proposes the Flooding-DVMAC protocol(Depth and Vector Based MAC Protocol)in the data link layer.In that protocol,the flood stateless routing mode in DVBR-Broadcast is combine with the REQ/REP request-response mechanism,so that the next-hop node is determined at a low cost,the nodes in the network perceive the information exchange process to reduce the conflict,and the algorithm flow is optimize to coordinate the time scheduling of the nodes.Compared with DVBRBroadcast,the transmission success rate of Flooding-DVMAC is improved by 11%,and the energy consumption is reduced by 71%～89%.Compared with DBRBroadcast,the transmission success rate and energy consumption are improved more.Compared with Flooding-DMAC protocol,the transmission success rate is improved by 2.7% and the end-to-end delay is reduced by 10%.