Method and apparatus for multiplexing voice and data on a single analog-loop telephone line

An improved data circuit terminating equipment (DCE), wherein the improvements comprise:

• (a) a micro-controller having operating logic for operating the DCE in a simultaneous voice and data (SVD) mode,
• the operating logic, while operating the DCE in the SVD mode, transmits voice at nominally fixed time intervals, in accordance to a voice protocol over an analog-loop telephone line, using unnumbered information (UI) frames of a frame based transmission protocol that provides for multiple logical channels, and identifying the voice transmissions as being intended for a first of the logical channels by setting a data link connection identifier (DLCI) of each of the UI frames to the first logical channel's identification value, and transmitting either data or information to be exchanged with a cooperating DCE at the other end of the telephone line over the same telephone line when not transmitting voice, using numbered information (I) frame of the same frame based transmission protocol, and identifying the non-voice transmissions as intended for a second of the logical channels by setting the DLCI of each numbered information frames to the second logical channel's identification value.

A method for multiplexing voice and data over an analog-loop telephone line by a data circuit terminating equipment (DCE), the method comprising the steps of:

• (a) transmitting voice at nominally fixed time intervals, in accordance to a voice protocol over the telephone line by a microcontroller, using unnumbered information (UI) frames of a frame based transmission protocol that provides multiple logical channels, and identifying the voice transmissions as being intended for a first of the logical channels by setting a data link connection identifier of each of the UI frames to the first logical channel's identification value;
• and
• (b) transmitting either data or information to be exchanged with a cooperating DCE at the other end of the telephone line over the same telephone line, by the microcontroller, when not transmittin.q voice, using numbered information (I) frames the same frame based transmission protocol, and identifying the non-voice transmissions as being intended for a second of the logical channels by setting the DLCI of each of the I frames to the second logical channel's identification value.