Date Added: Sep 2011
In this paper, the authors study the fundamental optimization problem in Wireless Sensor Networks of base-station positioning such that data from the sensors may be transmitted to it in an energy-efficient manner. They primarily consider the setting where a sensor transmits all of its data directly to the base-station or relays it via one other node. This setting provides two benefits: low duty-cycling due to limited synchronization requirements between nodes and low end-to-end delay due to the limited number of hops in the routes. Given the battery limitations of the sensor nodes, their objective is to maximize the network lifetime.