Wireless Network Research Institute, National Institute of Information and Communications Technology, Yokosuka 239-0847, Japan.
Sensors (Basel). 2013 Jun 7;13(6):7472-91. doi: 10.3390/s130607472.
An essential application of wireless sensor networks is to successfully respond to user queries. Query packet losses occur in the query dissemination due to wireless communication problems such as interference, multipath fading, packet collisions, etc. The losses of query messages at sensor nodes result in the failure of sensor nodes reporting the requested data. Hence, the reliable and successful dissemination of query messages to sensor nodes is a non-trivial problem. The target of this paper is to enable highly successful query delivery to sensor nodes by localized and energy-efficient discovery, and recovery of query losses. We adopt local and collective cooperation among sensor nodes to increase the success rate of distributed discoveries and recoveries. To enable the scalability in the operations of discoveries and recoveries, we employ a distributed name resolution mechanism at each sensor node to allow sensor nodes to self-detect the correlated queries and query losses, and then efficiently locally respond to the query losses. We prove that the collective discovery of query losses has a high impact on the success of query dissemination and reveal that scalability can be achieved by using the proposed approach. We further study the novel features of the cooperation and competition in the collective recovery at PHY and MAC layers, and show that the appropriate number of detectors can achieve optimal successful recovery rate. We evaluate the proposed approach with both mathematical analyses and computer simulations. The proposed approach enables a high rate of successful delivery of query messages and it results in short route lengths to recover from query losses. The proposed approach is scalable and operates in a fully distributed manner.
无线传感器网络的一个重要应用是成功响应用户查询。由于无线通信中存在干扰、多径衰落、数据包碰撞等问题，查询数据包在查询传播过程中会丢失。传感器节点上查询消息的丢失会导致传感器节点无法报告请求的数据。因此，可靠且成功地将查询消息分发给传感器节点是一个具有挑战性的问题。本文的目标是通过本地化和节能的发现和恢复来实现查询消息到传感器节点的高成功率传递。我们采用传感器节点之间的局部和集体合作来提高分布式发现和恢复的成功率。为了实现发现和恢复操作的可扩展性，我们在每个传感器节点采用分布式名称解析机制，允许传感器节点自行检测相关查询和查询丢失，并对查询丢失进行本地有效响应。我们证明了查询丢失的集体发现对查询传播的成功率有很大影响，并揭示了通过使用所提出的方法可以实现可扩展性。我们进一步研究了 PHY 和 MAC 层集体恢复中的合作和竞争的新特点，并表明适当数量的探测器可以实现最佳的成功恢复率。我们通过数学分析和计算机模拟来评估所提出的方法。所提出的方法能够实现查询消息的高成功率传递，并在恢复查询丢失时实现较短的路由长度。所提出的方法是可扩展的，并以完全分布式的方式运行。
