基于混合汇聚节点的无线传感器网络数据收集方法

在固定传感器网络中加入移动汇聚节点能降低整个网络的能量消耗、延长网络生存时间、增加网络容量。考虑网络中固定与移动汇聚节点共存的工作模式，提出了一种数据收集方法：在兼容网络原有固定汇聚节点模式的同时支持一个到多个移动汇聚节点，移动汇聚节点定期向其附近小范围内的传感器节点扩散自己的存在信息，传感器节点向离自己跳数最小的汇聚节点发送或者转发数据包。距离移动汇聚节点一跳的传感器节点通过应答-超时重传的方法来保证到移动汇聚节点的可靠数据传输。仿真研究表明：相对于传统固定传感器网络，使用该方法能够大幅度延长网络寿命(正常流量情况下延长600%以上，大流量情况下延长350%以上)；在网络高负载时最高数据传输成功率能达到91%，比节点全静止时提高了8.3倍，最低数据传输延迟仅为46.5ms，比节点全静止时减小了92%。

A data collection method with hybrid sinks in wireless sensor networks

The lifetime of wireless sensor networks can be improved by introducing mobile sinks. A data collection method is proposed in order to support hybrid sink mode in wireless sensor networks where static and mobile sinks coexist. One or more mobile sinks cooperate with the static sink(s). These mobile sinks broadcast status update periodically to only a subset of adjacent nodes. Sensor nodes send or forward data packets to the sink which is the nearest in hop counts. The correct data transmission between the mobile sinks and the last hop sensor node is guaranteed by using ACK-RETRANSMIT method. Using this method, the network lifetime improves with the increase of the number of mobile sinks. Simulation study shows that more than 600% lifetime improvement achieves when the ratio of the mobile sinks to the sensor nodes is above 7.5%. When the load of network is high, the maximum success rate of data transmission achieves 91%, which is 8.3 times compared to the network with only one static sink. Meanwhile, data transmission delay remains at a low level.