Abstract: Concerning the serious packet loss and high end-to-end delay in wireless sensor networks, a Routing Protocol Optimized for Data Transmission Delay (RPODTD) was proposed. Firstly, according to the data transmission result, the channel detection conditions were classified, and the effective detection ratio and transmission efficiency were introduced as the evaluation indexes of nodes. Then, the queuing delay of data packet was estimated by the difference between actual delay and theoretical delay. Finally, the maximum and minimum queuing delay thresholds were given for judging whether to change the transmission path according to the interval that the queuing delay belongs to. In the simulation experiment on OMNeT++, compared with link quality and delay based Composite Load Balancing routing protocol (ComLoB) and Congestion Avoidance multipath routing protocol based on Routing Protocol for Low-power and lossy network (CA-RPL), RPODTD has the average end-to-end delay of nodes reduced by 78.87% and 51.81% respectively, and the node loss rate reduced by 40.71% and 68.43% respectively, and the node mortality rate reduced by 25.42% and 44.62% respectively. The simulation results show that the proposed RPODTD can effectively reduce the end-to-end delay, decrease the packet loss rate and extend the network life cycle.

Key words: Wireless Sensor Network (WSN), routing protocol, delay, threshold, packet loss rate

摘要： 针对无线传感器网络中存在的数据包丢失严重以及端到端延时较高的问题，提出了一种数据传输延时优化的路由协议（RPODTD）。首先，根据数据包传输结果对信道探测情况进行分类，引入有效探测占比与传输效率作为节点的评价指标；然后，通过实际延时以及理论延时的差值估算数据包的排队延时；最后，给定最大和最小排队延时阈值，根据排队延时所属的区间判断是否更改传输路径。在OMNeT++上进行的仿真实验中，与基于链路质量和延时的复合负载均衡路由协议（ComLoB）和拥塞避免多路径路由协议（CA-RPL）相比，RPODTD节点的平均端到端延时分别降低了78.87%和51.81%，节点丢包率分别降低了40.71%和68.43%，节点的死亡率分别降低了25.42%和44.62%。仿真结果表明，RPODTD能有效地减少端到端延时，降低丢包率，延长网络生命周期。

关键词: 无线传感器网络, 路由协议, 延时, 阈值, 丢包率