| 摘要 |
A dual modem automatically switches between a wireless and wire-based communication modes using mode selection circuitry that detects when a wire-based communications network, such as a standard land-line telephone network, is coupled to the modem. When the modem selection circuitry detects the presence of the wire-based communications network, it couples modem processing circuitry to a wire-based interface. When the modem selection circuitry fails to detect the presence of the wire-based communications network, it couples the modem processing circuitry to a wireless interface and the wireless interface is also powered for coupling to a wireless communications network, such as a cellular phone network. The wireless interface is not powered when the modem is coupled to the wire-based communications network. |
