【作者】 王可；

【导师】 崔军红；

【作者基本信息】 吉林大学 ， 计算机技术（专业学位）， 2023， 硕士

【摘要】 水下传感器网络广泛应用于海洋环境监测、污染监测、海洋资源勘探等方面,通常需要处理紧急事件任务和长期观测任务。紧急任务网络需要保证数据的实时性,对传播延迟有较高要求;观测任务网络需要保证数据的质量、数量和稳定性,对传输成功率和能量消耗有较高要求。任务型水下传感器网络由大量随机部署在监测区域内的水下节点和水面的汇聚节点组成,由于水声通信复杂、节点能量有限,如何根据水下环境设计网络协议并达到任务目标是工作的重点。为了解决任务型水下传感器网络协议设计面临的挑战并且满足不同任务目标对网络性能的需求。首先,本文在网络层提出了DVBR-Broadcast协议(Depth and Vector Based Routing Protocol,基于深度和矢量的路由协议)。根据节点深度及到节点间的向量进行路由决策,数据包沿着位置相对最佳的路径传输,路由发现成本很低。发送队列和深度阈值功能可以在一定程度上减少碰撞和多余转发。仿真结果显示,在不同的节点密度下,DVBR-Broadcast的传输成功率比DBR-Broadcast平均高出3.25%,比其端到端传播延迟大约低9%～18%,相比Flooding-Broadcast,DVBR-Broadcast的传输成功率平均高出13.5%,比其能耗低约62%,比其端到端延迟低约26.5%。DVBR-Broadcast在传输成功率、端到端延迟和能耗方面都获得提升,并且随着数据包变长和深度阈值的改变,其优势并没有降低,DVBR-Broadcast可以满足紧急任务对网络性能的需求。不过数据包大小和深度阈值对其性能有一定影响。仿真结果显示,当数据包由200字节增加到400字节时,DVBR的能耗增加21%,端到端延迟增加50%;当深度阈值增加到400时,其成功率降低2.3%,能耗降低17%,可见较短的数据包以及合适的深度阈值可以让其性能更加稳定。其次,为了应对长期稳定可靠的观测任务,本文在数据链路层提出了Flooding-DVMAC协议(Depth and Vector Based MAC Protocol,基于深度和矢量的MAC协议)。该协议通过将DVBR-Broadcast中洪泛无状态路由方式与REQ/REP请求应答机制相结合,以较低的代价确定下一跳节点,网络中的节点感知此信息交互过程来减少冲突,并优化算法流程来协调好节点的时间调度。与DVBR-Broadcast相比,Flooding-DVMAC的传输成功率提高11%,比其能耗降低71%～89%。比DBR-Broadcast在传输成功率和能耗方面提升更多,与Flooding-DMAC协议相比,其传输成功率提升2.7%,端到端延迟降低10%。更多还原

【Abstract】 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%.更多还原