| 摘要 |
The present invention relates to a method and apparatus for selectively enabling and disabling transmit and receive functions of a radio (figure 1A), and more particularly to a system and method utilizing an out-of-band signal over a time division duplex channel to control transmit (11) and receive (12) functions of a radio so as to synchronize with the functions of a remote modem (figure 2, 40). The invention relates to a system and method for synchronizing the transmit and receive modes of a radio via an out of band signal. The out of band signal is preferably a control tone at a predetermined frequency and is substantially coextensive with the communication signal to be transmitted. The radio filters a multiplexed signal and detects if the control tone is present. If the control tone is not detected, the radio preferably remains in the default receive mode. If the control tone is detected, the radio operates in the transmit mode for the duration of the control signal.
|
