Abstract
A Wireless Sensor Network (WSN) is a network comprised of sensor nodes and a designated device called a sink to which nodes transmit their sensed data. Nodes are low-cost, battery-powered devices with limited memory and computational power. Usually WSNs are deployed with a single sink and left unattended for a long time. During this time sensor nodes, communication links between the nodes, and the sink may go down or crash due to energy depletion, harsh environment, or for some other reasons. If the sink crashes, then the network becomes useless as the sink will not be able to collect data from nodes. One way of making the network more reliable is to deploy networks with more than one sink. Existing efficient data aggregation protocols developed for WSNs with a single sink may not show the similar efficiency in WSNs with multiple sinks. In this paper, we first define the data aggregation problem in WSNs with multiple sinks, and then propose two data aggregation algorithms for a WSN with multiple sinks that minimize the number of data packet transmissions during data collection. The first one is based on a Minimum Spanning Tree algorithm and the second one is based on a Shortest Path Tree algorithm. Simulation results show the effectiveness of the proposed algorithms.