Geographic Routing in Wireless Sensor and Actuator Networks

Position information enables development of localized routing methods where greedy routing decisions are made at each node, based solely on knowledge of positions of neighbors and the destination, with considerable savings in the communication overhead. Power consumption can be taken into account in the routing process. This chapter will survey existing flooding-based and positionbased routing schemes. It also describes a general cost to progress ratio-based approach for designing routing protocols under a variety of metrics, such as hop count, power, remaining energy, delay, and others. The chapter also describes routing with guaranteed delivery for unit disk graphs and an ideal medium access control (MAC) layer. Gabriel graph, as a localized planar and connected structure needed for such solutions is described. Solutions are expanded toward beaconless behavior, where nodes are not aware of their neighborhood. Georouting with virtual coordinates is based on hop distances to some landmarks. This chapter also discusses the physical layer aspects of georouting, routing in sensor-actuator networks, and the load-balancing issue in routing.