Efficient Minimum-Cost Bandwidth-Constrained Routing in Wireless Sensor Networks

A critical issue in the design of routing protocols for wireless sensor networks is the efficient utilization of resources such as scarce bandwidth and limited energy supply. Many routing schemes proposed in the literature try to minimize the energy consumed in routing or maximize the lifetime of the sensor network without taking into consideration limited bandwidth of wireless links. This can lead to congestion, increased delay, packet losses and ultimately to retransmission of packets, which will waste considerable amount of energy. This paper presents a routing protocol, which minimizes the total cost of routing while guaranteeing that the load on each wireless link does not exceed its capacity. The protocol is derived from a combinatorial optimization problem, known as the minimum-cost flow problem in the operations research literature. Because we use polynomialtime minimum-cost flow algorithms, the protocol is highly scalable. The proposed protocol is compared with the maximum lifetime bandwidth constrained routing protocol [1] (formulated as an Integer Linear Program). Simulation results indicate that the proposed protocol achieves longer lifetimes, delivers more number of messages and has higher residual energy than the maximum lifetime bandwidth constrained routing protocol for the test example.