Patent ID: 6636595
Filing Date: 2003-10-21
Classification: H04M,H04Q

Abstract:
A non-key service unit (non-KSU) telephone apparatus for use with a plurality of telephone lines, comprising:a line interface having an input operatively coupled to the plurality of telephone lines and a plurality of outputs; a microcontroller operatively coupled to the line interface; a first multiplexer operatively coupled to the microcontroller and at least a portion of the plurality of outputs of the line interface, the first multiplexer multiplexing transmit and receive audio signals for the plurality of telephone lines; a high impedance line interference operatively coupled to the plurality of telephone lines, the high impedance line interface monitoring each of the plurality of telephone lines without adversely affecting a phase response of a modem signal on one of the plurality of telephone lines; and a second multiplexer operatively coupled to an output of the high impedance line interface and the microcontroller, the second multiplexer multiplexing data received over the plurality of telephone lines and provided by the high impedance line interface; a coder/decoder coupled to the first multiplexer, the microcontroller instructing the first multiplexer to couple one of the plurality of telephone lines to the coder/decoder, the coder/decoder receiving a telephone signal from the one telephone line, filtering and compressing the telephone signal, and converting the filtered compressed telephone signal to a digital signal; and a digital signal processor (DSP) operatively coupled to the coder/decoder and the microcontroller, the DSP analyzing the digital signal provided by the coder/decoder and determining whether the digital signal is a speech signal or DTMF tones, wherein if the DSP determines that the digital signal is DTMF tones, the DSP decodes the DTMF tones and provides the decoded DTMF tones to the microcontroller, and wherein if the DSP determines the digital signal is a speech signal, the DSP compresses the digital signal and stores the compressed digital signal in a memory.