Voice, data or both over one telephone line in a T-1 carrier system

A system for communicating over a standard T-1 span connected in a communication path between users and over digital switches, wherein the T-1 format comprises a superframe having a plurality of sequential frames with each frame comprising a predetermined number of sequential time slots, with each time slot having a fixed number of bit positions from a most to least significant bit position and further wherein the least significant bit positions in a fractional part of every superframe is reserved for T-1 signalling bits, said system comprising:

• encoding means for digitizing voice samples by limiting each sample to an encoded number of bit positions from a most to least-significant voice bit, which number is equal to said predetermined number of bit positions in said time slots;
• a source of data at each user location having a transmission speed adapted to fit within one bit position in each time slot of each frame assigned to said user location;
• means for separating the least and next-to-least significant bits in the digitized voice samples from said user location and assigning the next-to-least significant encoded voice sample bit to the least significant time slot bit position including those time slot bit positions reserved for T-1 signalling bits;
• means for assigning the data from said data source to the next-to-least significant bit position in each time slot;
• and
• means available to a user for simultaneously commanding that said time slot including combined voice and data be transmitted over said T-1 span.

A method for communicating over a standard T-1 span connected over digital switches in a patch between users, wherein the T-1 format comprises a superframe having a plurality of sequential frames with each frame assignable to a user by a telephone utility free of the user's control and each frame comprising a synchronizing pulse followed by a predetermined number of sequential time slots, with each time slot having a fixed number of bit positions from a most to least-significant bit position and further wherein the least significant bit positions in selected frames of every superframe is reserved by said utility without regard to received frame identity for T-1 signalling bits inserted by T-1 equipment free of any control by said user, said method comprising the steps of:

• digitizing a user's voice samples to an encoded number of bit positions equal to said fixed number of bit positions in said frames;
• placing data, voice samples and T-1 signalling bits during the time slots of selected frames in each superframe;
• allowing a user to command that digitized voice and the user's own data be simultaneously transmitted from one user location over one port of said T-1 span;
• discarding in response to said user's command the least significant bit position of said digitized voice sample, leaving the next-to-least significant position of said digitized voice sample temporarily unoccupied;
• moving in response to said user's command, the next-to-least significant voice sample to the bit position in said frame reserved for said T-1 signalling bit;
• placing in response to said user's command, said user's data from said one user location in the previously unoccupied bit position of the time slots assigned to said one user;
• and simultaneously transmitting both the user's encoded voice and the user's data over telephone company equipment provided with said T-1 span and T-1 format.