Evaluation of Cartesian-based Routing Metrics for Wireless Sensor Networks∗

Routing packets within a large-scale wireless sensor network (WSN) without storage overhead and routing table updates is a challenging problem. With a large number of sensors the overhead plays a significant role in the scalability of the routing protocol. To avoid this communication overhead, WSN routing demands new and efficient methods for routing packets. Remove or reduce this overhead, the routing protocol needs some way of implicitly, rather than explicitly, defining paths. In this paper, we use the idea of directional routing, which requires only that each sensor know its location within the network relative to the sending node and the destination. Through simulation, we evaluate and compare a number of different metrics for selecting the routing path on a hop-by-hop basis. We also compare the energy usage and path length of these local methods with respect to some routing techniques based on global information. This evaluation shows that changing the routing metric can dramatically effect the performance of the sensor network. These results also show tradeoff between extending the lifetime of the WSN and reducing the average number of hops a message travels to the base station.