Patent ID: 6493338
Filing Date: 2002-12-10
Classification: G01S,G08G,G10L,H04M

Abstract:
A multichannelinband signaling modem for communicating digital data over a voice channel of a telecommunications network, comprising:an input for receiving outbound digital data; a first modulator that converts a first binary bit value in a first portion of the outbound digital data into an outbound first audio tone having a first frequency and converts a second binary bit value in the first portion of the outbound digital data into an outbound second audio tone having a second frequency; a second modulator that converts a first binary bit value in a second portion of the outbound digital data into an outbound third audio tone having a third frequency and converts a second binary bit value in the second portion of the outbound digital data into an outbound fourth audio tone having a fourth frequency; a bi-directional port for outputting and receiving audio tones over the voice channel of the telecommunications network; a first decoder that is coupled to the port and monitors for inbound first and second audio tones and converts any detected inbound first audio tones into a first binary bit value of a first portion of inbound digital data and converts any detected inbound second audio tones into a second binary bit value of the first portion of inbound digital data; a second decoder that is coupled to the port and monitors for inbound third and fourth audio tones and converts any detected inbound third audio tones into a first binary bit value of a second portion of inbound digital data and converts any detected inbound fourth audio tones into a second binary bit value of the second portion of inbound digital data; and a controller that controls when the first and second modulators generate outbound audio tones and when the first and second decoders monitor for inbound audio tones.