We study the problem of power control in the physical layer of wireless ad hoc networks with a view to increasing the network's quality of service, reducing power consumption, and decreasing interference. We propose a new power control algorithm, and use game theory to analyze its performance, where each user's quality of service is a function of its signal-to-interference-plus-noise-ratio (SINR). The utility function for each user is defined by its desired SINR minus a pricing to provide adequate incentive for each user to choose its power level in such a way to maximize the aggregate of all users' utilities (total network utility) instead of selfishly maximizing its own SINR. Simulation results show improvement in the network's performance at reduced power levels.