Optimization of transport capacity in wireless multihop networks

Gamal et al. (IEEE Trans. Inform. Theory 52:2568–2592, 2006) showed that the end-to-end delay is n times the end-to-end throughput under centralized time division multiple access scheduling. In our other work (IEEE Trans. Mobile Computing, in press), it was proved that the relationship between the end-to-end throughput and the end-to-end delay of Gamal et al. still holds under the IEEE 802.11 distributed coordination function (DCF) when the carrier sensing range and the packet generation rate are jointly optimized. The main purpose of this study is to determine whether the result in our other work is achievable when the transmission range is adjusted instead of the carrier sensing range. To this end, we revise the transport capacity by reflecting a queue at each node and optimize the revised transport capacity by jointly controlling the transmission distance and the packet generation rate. Under our system model, it is shown that the end-to-end throughput and the end-to-end delay scale are Θ1/nlogn and Θn/logn, respectively, where n is the number of nodes in the network. That is to say, the result that the end-to-end delay is n times the end-to-end throughput under the DCF mode is also estabilished while jointly optimizing the transmission range and packet generation rate.