A wireless modem is a device which is used to transmit and receive data over a network. Power consumption for wireless devices becomes a challenge for researchers, causing the entire research environment to shift their focus to the power usage of wireless devices. Presently, by using a class A power amplifier, a power efficient wireless modem can be achieved. Class A power amplifiers take input in the form of DC power and send it to the transistor's drain. The power amplifiers will amplify the input signal in order to transmit the signal over a network. Modem efficiency is measured by the fraction of output given by the Class A power amplifier and the given input power. If we compare wireless modems without power amplifiers, it shows a drastic decrease in power consumption when using a power amplifier circuit. The output power of a power amplifier is directly proportional to the output of the wireless modem. Therefore, the efficiency of the power amplifier increases with the efficiency of the modem. Finally, by use of power amplifier circuit, we can achieve a power efficient wireless modem. The same theory can be applied in communication networks to achieve efficient transmission channels and receiving channels. In this paper, we develop a new power consumption model to measure the power consumption of all major components of a communication channel. Simulation results demonstrate a significant reduction in the power consumption which in turns improves the overall efficiency of a wireless modem.