Rate-Power-Range Design Tradeoffs in IEEE 802.11 based Ad Hoc Wireless Networks

In this paper, we study cross-layer design tradeoffs between settings of the transmission data rate, the transmission power and the forwarding range in both single hop and multihop IEEE 802.11 based ad hoc wireless networks while taking the effect of capture into account. We perform the study by developing an approximate mathematical model for calculating throughput and delay in the underlying network, and validating our results via simulation. Using data rate and power level settings that are present in commercially available IEEE 802.11b radios, we show that in networks with lower nodal spatial density, operations that select higher power values along with higher data rate level settings, using relatively longer distance forwarding ranges, tend to exhibit enhanced delay-throughput performance characteristics. For other networking configurations, our analytical methods can be employed to determine the effective settings of the transmit power, data rate and forwarding range levels. We also note that the optimal value of the transmit power, the forwarding range and the operating data rate is highly dependent on the propagation model used as well as on the network´s topology and congestion levels