关键词: 无线传感器网络, 中位数查询, 抽样算法, 聚集算法

Abstract: A Sampling Algorithm for Median Query (SAMQ) based on Wireless Sensor Network (WSN) was proposed. In SAMQ, each node in WSN created a fresh sample summarizing its own observed values and the received values from children nodes, and then broadcasted its subsequence to the parents. Finally, these samples were combined to a single sample in the root node whose data structure was far smaller than the size of the whole data set. The approximate value for median query could be obtained from the sample quickly. A shared channel was used to reduce packet loss. Analytical and experimental results show that the proposed algorithm has the advantages of low power consumption, small error range, and is able to significantly prolong network lifetime.

Key words: Wireless Sensor Network (WSN), median query, sampling algorithm, aggregate algorithm