Hop-by-Hop versus End-to-End Congestion Control in Wireless Multi-Hop UWB Networks

We perform a comparative study of the performance of hop-by-hop and end-to-end congestion control mechanisms for wireless multi hop network. We consider the effect of using different utility functions and study their effect on throughput and peak queue size. The multiple access communication is assumed to be ultra-wide bandwidth (UWB) time-hopping spread-spectrum (TH-SS) impulse radio. The joint congestion and power control is formulated as an optimization problem which is then solved by distributed iterative algorithms for flow rate adaptation and power adaptation. Significant reduction in the buffer size requirement can be achieved by using hop- by-hop approach, under high propagation delays. Use of power control reduces the buffer size requirement, in addition to providing improvement in energy efficiency.