Power Consumption of Wireless NIC and Its Impact on Joint Routing and Power Control in Ad Hoc Network

Abstract

As an effective technique to achieve low power in Ad Hoc network, the Joint Power Control and Routing (JPCR) has recently attracted a lot of interests. In most existing papers, RF transmission energy is considered as the major energy cost for frame delivery. However, the measurement results show that RF transmission power is only a neglectable fraction of the total power consumption of a Wireless Network Interface Card (WNIC). The fact implies that existing JPCR algorithms may not bring the supposed energy saving. In this paper, we adopt an accurate but efficient model to describe the power consumption behavior of a transmission power controllable WNIC, based on which the minimal energy cost of frame delivery and QoS constrained optimal transmission power level are formulated aiming at lowing down the total energy consumption of WNIC. Furthermore, we investigate the significant impact when considering the total energy consumption instead of only the RF transmission energy. In contrast to previous transmission energy minimized schemes that tend to span the path onto a large set of very short hops, the WNIC energy optimal JPCR reaches a tradeoff between the number of hops and the length of hops.