A Message-Optimal Sink Mobility Model for Wireless Sensor Networks

The paper proposes an algorithm for collecting data from a wireless sensor network modeled as a random geometric graph in the unit square. The sensors are supposed to work in an asychronous communication mode (they store the measures they perform and transmit a message containing the data, upon receival of a trigger signal). The model assumes a mobile sink passing near the sensors, and asking the sensors to transmit their data. The algorithm defines a route for the sink such that the number of messages that a sensor needs to transmit be as low as possible. We also present a kind of ldquocontrolledrdquo random walk in a(connected) random geometric graph that is based upon the main idea of the sink routing algorithm, reducing the graph cover time to Theta(n log log n) instead of Theta(n log n) needed when a simple random walk is performed.The model can be generalized for the case of more than one mobile sink, and the algorithm can be modified to deal with locally uniform density of sensors deployed in the field.