Tasking Distributed Sensor Networks

Abstract

Distributed wireless sensor networks provide significant new capabilities for automatically collecting and analyzing data from physical environments. Such sensor networks gather and analyze data in response to queries posed by users of the network. By using more sensor nodes than is strictly necessary to cover an area, these sensor networks can provide reliable information, tolerate many types of faults, and have a long effective lifetime. Like most wireless systems, however, these sensor networks must effectively manage power consumption to achieve a satisfactory system lifetime. Power management at the node level, including low power hardware and power aware operating systems, can provide significant savings in power consumption. In this paper, we present algorithms for managing power at the distributed system level, rather than just at the individual node level. These distributed algorithms determine which set of sensor nodes will be tasked with a given user query and which sensor nodes will remain in an idle state conserving power. The goal of the algorithms is to extend the effective service time of the entire network. In this paper, we give a theoretical analysis of these algorithms along with extensive simulation results.