Delay- Constrained Capacity of the I E E E 802.11 D C F in Wireless Multihop Networks
Abstract: Gamal et al. showed that the end-to-end delay is times the end-to-end throughput under the centralized TDMA scheduling [4] where is the number of nodes in the network, and defined this relationship as the optimal tradeoff between the end-to-end throughput and the end-to-end delay. The main purpose of this paper is to show whether this tradeoff relationship is established when IEEE802.11 DCF is used. We mathematically express the end-to-end throughput and the end-to-end delay as a function of carrier sensing range and packet generation rate. We optimally control them in order to derive a delayconstrained capacity, the maximum value among the end-to-end throughput in which the end-to-end delay requirement is satisfied. As a result, we show that IEEE 802.11 DCF can establish the optimal tradeoff relationship in [4]. This indicates that the optimally controlled parameters can compensate the loss from the difference between the centralized TDMA scheduling and IEEE 802.11 DCF.