Performance of Routing in Sensor Networks with a Mobile Access Point

Routing streaming data in a sensor network is a task made arduous by the resource constraints imposed on each node. Furthermore, it is widely expected that the gateway of the sensor network will not be static in many application scenario, but will be moving about the network. We study a simple protocol and consider the cost it imposes on the networks in terms of number of messages sent, or equivalently, bandwidth or power usage. We study the scaling behavior of the so-called bread crumbs protocol and show that it is optimal in its scaling behavior in one- and two-dimension graphs. We compare this protocol with the cost of routing on the shortest path from the sensor node to the mobile sink, and with the cost of flooding the network in the hope of finding the sink. We positively support the analysis with some simulations of the bread crumbs protocol in both a lattice and a torus scenario.