Power, rate, and energy trade-offs in wireless ad hoc and mesh networks

Power, rate and energy control in wireless ad hoc and mesh backbone networks have been the topic of many research works in the last decade. However, to the best of our knowledge, no work has yet examined the effect of the joint selection of those three parameters on the network's throughput, delay, and bit-per-joule performance.;In order to study this problem, we first introduce an analytical approach for calculating an approximation to the throughput and packet delay performance in multihop networks by assuming that packets that belong to a flow traverse the network by being transported across multiple sub-networks where only one successful transmission can occur at any given time. Each such sub-network is then analyzed independently.;Using this mathematical model, and assuming that nodes are equipped with software controlled radios whose parameters can be dynamically adjusted, we proceed to study the effect of the transmit power level, data rate and forwarding range on the throughput and delay performance of a wireless ad hoc network with a flat hierarchy. Our performance analyses show that the throughput-capacity level tends to increase as the transmit power level used in the network increases. Our results also show that operating at the lowest transmit power value that keeps the network connected often yields distinct degradation in the throughput and the delay performance. This is mainly due to the fact that the higher spatial re-use factor introduced by operating at lower transmit power levels is typically not sufficient to offset the resulting increase in the average path length of a flow's route.;We then present a mathematical model to estimate the maximum throughput attainable in a wireless mesh backbone network and also use this model to study the effect of the transmit power level and data rate of the system. We finally proceed to study the bit-per-joule performance of both flat hierarchy and mesh-backbone wireless network networks that use the 802.11 CSMA/CA MAC protocol. We find out that increasing the transmit power level increases the bit-per-joule performance of both network topologies.