Distributed Data Gathering in Multi-Sink Sensor Networks with Correlated Sources.pdfVIP

Distributed Data Gathering in Multi-Sink Sensor Networks with Correlated Sources Kevin Yuen, Baochun Li, Ben Liang Department of Electrical and Computer Engineering University of Toronto, Ontario, Canada {yuenke, bli}@eecg.toronto.edu, liang@comm.utoronto.ca Abstract. In this paper, we propose an effective distributed algorithm to solve the minimum energy data gathering (MEDG) problem in sensor networks with multiple sinks. The problem objective is to find a rate al- location on the sensor nodes and a transmission structure on the network graph, such that the data collected by the sink nodes can reproduce the field of observation, and the total energy consumed by the sensor nodes is minimized. We formulate the problem as a linear optimization problem. The formulation exploits data correlation among the sensor nodes and considers the effect of wireless channel interference. We apply Lagrangian dualization technique on this formulation to obtain a subgradient algo- rithm for computing the optimal solution. The subgradient algorithm is asynchronous and amenable to fully distributed implementations, which corresponds to the decentralized nature of sensor networks. Key words: Sensor networks, data correlation, distributed algorithm, min- imum energy, optimal rate allocation, transmission structure 1 Introduction Many applications for sensor networks, such as target tracking [1] and habitat monitoring [2], involve monitoring a remote or hostile field. Sensor nodes are assumed to be inaccessible after deployment for such applications and thus their batteries are irreplaceable. Moreover, due to the small size of sensor nodes, they carry limited battery power. Thus, energy is a scarce resource that must be conserved to the extent possible in sensor networks. In this context, we are interested in solving the MEDG problem in multi-sink sensor networks with correlated sources. The first part of the problem objective is to find an optimal rate allocation on the sensor nodes, suc