A radio frequency (RF) transmitter is coupled to and controlled by a processor to transmit data. A physical layer circuit is coupled to the RF transmitter to encode and decode between a digital signal and a modulated analog signal. The physical layer circuit comprises a high rate physical layer circuit (HRP) and a low rate physical layer circuit (LRP). The low rate channels generated by the low rate physical layer circuit (LRP) share a same frequency band as a corresponding high rate channel generated by the high rate physical layer circuit (HRP).