Wireless Sensor Networks

5.3 Information-Based Sensor Tasking 157

disk centered at x with some radius r, where r is determined by the

observation model. In practice, we choose r based on the maximum

detection range plus a moderate amount of margin to account for

possible target motion during a sample period.

Ideally, nodes in an alarm region should collaborate to resolve

their contention and elect a single leader from that region.

However, the exact location of the alarm region is unknown since

the target position x is unknown. Each node with a detection only

knows that the target is within a distance of r, and a possible competi-

tor could be a farther distance r from the target. Thus in the absence

of a “message center,” a node notifies all nodes within a radius 2r of

itself ...