数据收集是无线传感器网络的一个基本功能.然而,现有的教据收集模式大都是基于静止基站的网络结构,导致基站周围的节点由于担负着网络内的所有负载而快速死亡,成为网络性能的瓶颈.研究如何利用移动基站收集教据来达到负载平衡.提出了一个利用移动基站协助教据收集的模式(movement—assisteddatagathering,简称MADG),它将基站移动区域设置为缓冲区,首先将教据沿最短路径传输到缓冲区内,然后在基站移动的过程中进行数据收集.证明了缓冲区位置设置在距离中心42R/2时教据传输总能耗最少,并证明了存在一个缓冲区位置使得最大节点负载最小化,进而确定了同时考虑到能源消耗和负载平衡的基站移动区域.理论分析和实验结果表明,提出的数据收集模式在很大程度上降低了网络节点的最大负载,并且减少了数据传输能源中的消耗,分别比固定基站和同类工作的最大网络负载降低95%和80%以上.
Data gathering is the basic function of the sensor networks. However, the existing gathering schemes are almost based on the architecture with a static base station which results in the quick death of nodes around the base station. The reason is that the sensor nodes located near a base station have to relay data for a large part of the network and thus deplete their batteries very quickly. This paper discusses how to use the mobile base station for data gathering with load-balancing. A data gathering scheme MADG (movement-assisted data gathering), which makes use of the mobile base station for data collection, is presented. In this scheme, the base station moves in a stationary annularity area exploited for data buffering. The gathered data,are firstly forwarded into the buffering area and then collected by the mobile base station. It is theoretically proved that the location /R/2 away from the center is the optimal location for minimizing the energy consumption for transmitting data and that there exists a location which can make the maximal node load minimize. This paper then considers the optimum location jointing the energy consumption and load-balancing based on above analyses. Compared with the static base station scheme and the existing mobile base station scheme, MADG reduces the load by over 95% and 80%, respectively.