an energy efficient ofdm transceiver includes a transmitter using a decision processor to control first internal elements that can be operated in parallel and can be selectively powered off or hibernated , and a receiver using a processing decision element to control second internal elements that can be operated in parallel and can be selectively powered off or hibernated , wherein control of the first and second internal elements enables tracking status of network traffic , adjustment of ofdm bandwidth based on a traffic decision and selectively powering off or hibernating parallel ones of the first and second internal elements .