Each terminal makes an adjustment in its own power to maximize its utility. At the equilibrium of this system, each terminal receives a utility that cannot be enhanced any further by individual effort. However, the performance of all terminals can be improved by introducing limited cooperation into the system. The improvement can be accomplished by pricing the transmit power of a terminal which acts as an incentive for a terminal to decrease its power in return for increased utility. When the terminals in a system with only voice maximize their utilities, the resulting equilibrium is also an efficient operating point.
Pricing brings no improvement to the terminals in such an equilibrium.
In the presence of data terminals, qualitatively, the point that maximizes the utility of the voice terminal remains the same. However, the actual power that achieves the same result is higher. Furthermore, all the terminals improve their utilities in a heterogeneous system if pricing is present. With pricing, all the voice terminals receive the same SIR at equilibrium while SIR received by data terminals are ordered with respect to their relative path gains. In the system with multimodal terminals, the data and voice traffic each terminal generates is modeled in a single utility function.