Geographic Routing With Limited Information in Sensor Networks

Geographic routing with greedy relaying strategies are important routing schemes in sensor networks. These schemes assume that the nodes have perfect information about the location of the destination. When the destination is unit distance away, the asymptotic routing delays are Θ(1/M(n)) , where M(n) is the maximum distance traveled in one hop (transmission range). We consider three scenarios where: i) nodes have location errors (imprecise GPS); ii) only coarse geographic information about the destination is available, e.g., the quadrant in which the destination is located; and iii) only a small fraction of the nodes have routing information. In this paper, we show that even with such limited destination-location information, the routing delays are Θ(1/ M(n)) , and validate our analysis with simulations. Finally, we consider the throughput-capacity of networks with progressive routing strategies that take packets closer to the destination in every step, but not necessarily along a straight-line. While such a routing strategy could lead to spatial “hotspots” due to the suboptimal flows nonuniformly loading the network, we show that the effect of hot spots due to progressive routing does not reduce the network throughput-capacity in an order sense, i.e., is order-wise the same as the maximum achievable throughput-capacity.