基于预取机制的传感器网络移动查询技术

Approach of Mobile Querying Based on Message Prefetch for Wireless Sensor Networks

无线传感器网络技术所面临的关键问题之一是解决向终端用户提供传送信息的数据服务问题。提出了一种移动环境下满足时间空间约束的数据查询处理技术,结构上由代理体和网络节点两层组成,其中网络节点执行消息预取、查询扩散和数据收集处理功能,通过对用户的运动路线进行预测并向传感节点发出预取消息,由节点自主构建网络查询树,再由数据集中组件完成数据的收集和融合,用户在到达传感区域后能在查询周期结束前获取查询数据。仿真表明该技术能以较低的能量消耗提供高的数据服务质量。

This paper presents a spatiotemporal query service called Mobile-Query that allows mobile users to periodically gather information from their surrounding areas through a wireless sensor network.The key advantage of Mobile-Query lies in its capability to meet stringent spatiotemporal performance constraints crucial to many applications. These constraints include query latency, data fresh- ness and data integrity,and changing query areas due to user mobility.A novel query technology based on just in-time prefetching enables Mobile-Query to maintain robust spatiotemporal guarantees even when nodes operate under extremely low duty cycles.Furthermore,it significantly reduces the energy consumption and network contention caused by continuous queries from mobile users.Both theoretical analysis and simulation results under a range of realistic setting of the approach show its feasibility and validity.