Patent ID: 7409195
Filing Date: 2008-08-05
Classification: H04M

Abstract:
1. An apparatus comprising: a base unit for coupling to a telephone line; and a remote unit for communicating with the base unit over a wireless medium; wherein the base unit includes a transmitter for direct analog modulation of an original analog voiceband data signal received over the telephone line and transmitting the modulated signal over the wireless medium, and level control circuitry coupled to the transmitter that controls a level of the original analog voiceband data signal to be substantially in a linear range of the transmitter; wherein the remote unit includes a receiver for receiving the modulated signal over the wireless medium and direct analog demodulation of the original analog voiceband signal, and an interface to a modem circuit for decoding a data stream encoded in the original analog voiceband signal; wherein the level control circuitry that controls a level of the signal comprises an automatic gain control circuit that controls a peak level of the signal; and wherein the automatic gain control circuit uses a dial tone of a telephone connection or a DC current of a telephone loop to set a gain level for the original signal at a beginning of communication, the gain level remaining substantially constant during communication.