A first transmitting device is used to transmit a first signal on a first carrier frequency to a relay device. The relay device receives the signal by demodulating the first carrier frequency. Subsequently, the relay device retransmits the signal by modulating a second and/or a third carrier frequency. The signal is then recovered at one or more receiving devices by demodulating the second and/or third carrier frequencies. Further, a second transmitting device transmits a second signal on a fourth carrier frequency and the relay device retransmits the signal by modulating a fifth and/or a sixth carrier frequency. The signal is then recovered at one or more receiving devices by demodulating the fifth and/or sixth carrier frequencies. The transmitting and/or receiving devices are preferably voice terminals, such as a wireless telephones or data terminals, such as portable computers. The transmitting and/or receiving devices are optionally coupled to a communications network, such as a public switched telephone network or the Internet. The relay device is preferably a multiple beam satellite and/or a ground station covering several distinct geographical regions.