Method and apparatus for time multiplex transmission of electrical digital signals comprising a plurality of transmission channels

Claim 1

A system for multiplex transmission of a plurality of transmission channels over transmission means comprising in combination: a transmitter for main and auxiliary channels of said plurality of transmission channels comprising a first and second input circuit each having a plurality of input leads coupled thereto for receiving input signals comprising long and short code words from respective message sources; a clock signal source; a time slot counter coupled to said clock source providing an output of a plurality of slot pulses defining a channel period thereby; a main channel counter circuit cOupled to said time slot counter and being advanced by a pulse therefrom every channel period and providing a plurality of output pulses defining a frame period and being coupled to said first input circuit to provide channel period timing signals thereto; an information converter coupled to said first and second input circuit for converting each input signal into a digital code word suitable for synchronous, multiplex transmission; a first and a second storage device coupled to said information converter, said first storage device being assigned to said main channels and said second storage device being assigned to said auxiliary channels; an auxiliary channel counter circuit coupled between said information converter and said second input means, being operative to be advanced one half count or three time slots upon the occurrence of a short code word in either the main channels or auxiliary channels; a control circuit coupled to said information converter and receiving inputs from said time slot counter and said first storage device to effect transmission of said long code words in said main channels but selectively coupling said short code words into predetermined auxiliary channels during certain channel periods to utilize heretofore unused transmission time; an output unit coupling a multiplexed output signal from said information converter to said transmission means, and a receiver.

Claim 2

A system for multiplex transmission of a plurality of transmission channels over transmission means comprising in combination: a transmitter for main and auxiliary channels of said plurality of transmission channels comprising a first and second input circuit each having a plurality of input leads coupled thereto for receiving input signals comprising long and short code words from respective message sources; a clock signal source; a time slot counter coupled to said clock source providing an output of a plurality of slot pulses defining a channel period thereby; a main channel counter circuit cOupled to said time slot counter and being advanced by a pulse therefrom every channel period and providing a plurality of output pulses defining a frame period and being coupled to said first input circuit to provide channel period timing signals thereto; an information converter coupled to said first and second input circuit for converting each input signal into a digital code word suitable for synchronous, multiplex transmission; a first and a second storage device coupled to said information converter, said first storage device being assigned to said main channels and said second storage device being assigned to said auxiliary channels; an auxiliary channel counter circuit coupled between said information converter and said second input means, being operative to be advanced one half count or three time slots upon the occurrence of a short code word in either the main channels or auxiliary channels; a control circuit coupled to said information converter and receiving inputs from said time slot counter and said first storage device to effect transmission of said long code words in said main channels but selectively coupling said short code words into predetermined auxiliary channels during certain channel periods to utilize heretofore unused transmission time; an output unit coupling a multiplexed output signal from said information converter to said transmission means, and a receiver.

Claim 5

A method for multiplex signal transmission from a plurality of input lines of a transmitter to a corresponding plurality of output lines of a receiver comprising the steps of: dividing the total transmission time into frame periods of equal duration; subdividing each frame period into a predetermined number of channel periods smaller in number than the number of said plurality of said input and output lines respectively; assigning each of said input lines and the corresponding output line either to a main channel or to an auxiliary channel, the number of main channels being equal to said predetermined number of channel periods; assigning each channel period of a frame period to one predetermined main channel; subdividing each channel period into a predetermined number of timeslots; dividing the class of signals comprising operating signals for performing control functions, and code signals which represent the information to be transmitted into two groups, one consisting of a majority of signals of said class which occur less frequently in a typical transmission interval and another consisting of a minority of signals of said class which occur more frequently in a typical transmission interval; assigniNg to each signal of the majority group a code combination consisting of a first number of bits, which is not greater than the number of time slots contained in one channel period; assigning to each signal of the minority group a code combination consisting of a second number of bits which is smaller than said first number of bits; converting each signal received on said input lines to a code combination assigned thereto; and transmitting during predetermined channel periods or fractions thereof sync signals, and transmitting during each remaining channel period a code combination converted from a signal of the main channel assigned to this channel period, and occupying either a whole channel period or a fraction of a channel period depending whether the signal belongs to said majority or to said minority group, and transmitting during each nonoccupied fraction of a channel period bits of a code combination converted from a signal of an auxiliary channel.

Claim 6

A method for multiplex signal transmission from a plurality of input lines of a transmitter to a corresponding plurality of output lines of a receiver comprising the steps of: dividing the total transmission time into frame periods of equal duration; subdividing each frame period into a predetermined number of channel periods smaller in number than the number of said plurality of said input and output lines respectively; assigning each of said input lines and the corresponding output line either to a main channel or to an auxiliary channel, the number of main channels being equal to said predetermined number of channel periods; assigning each channel period of a frame period to one predetermined main channel; subdividing each channel period into a predetermined number of timeslots; dividing the class of signals comprising operating signals for performing control functions, and code signals which represent the information to be transmitted into two groups, one consisting of a majority of signals of said class which occur less frequently in a typical transmission interval and another consisting of a minority of signals of said class which occur more frequently in a typical transmission interval; assigniNg to each signal of the majority group a code combination consisting of a first number of bits, which is not greater than the number of time slots contained in one channel period; assigning to each signal of the minority group a code combination consisting of a second number of bits which is smaller than said first number of bits; converting each signal received on said input lines to a code combination assigned thereto; and transmitting during predetermined channel periods or fractions thereof sync signals, and transmitting during each remaining channel period a code combination converted from a signal of the main channel assigned to this channel period, and occupying either a whole channel period or a fraction of a channel period depending whether the signal belongs to said majority or to said minority group, and transmitting during each nonoccupied fraction of a channel period bits of a code combination converted from a signal of an auxiliary channel.

Claim 9

A system for digital time multiplex transmission comprising in combination: a plurality of main and auxiliary input lines and of corresponding main and auxiliary output lines; a transmitter having a plurality of main and auxiliary input circuits each connected to one of said main and auxiliary input lines respectively for receiving and storing input signals from each of these input lines separately; pulse generating means delivering slot pulses each defining one time slot, and channel period pulses each defining one channel period; each main input circuit being assigned to one of said channel periods; signal converter means connected to said main input circuits for receiving during each channel period a signal representing the information to be transmitted from one of said main input circuits selected by the channel period pulse assigned thereto, said converter means being further connected to said auxiliary input circuits for receiving signals representing the information to be transmitted therefrom and for converting the received signals into corresponding code words, to be transmitted; the code words being divided into two groups, one group consisting of a majority of the code words which occur less frequently in a typical transmission interval and which consist of a number of bits not greater than the number of time slots within one channel period, and a second group consisting of a minority of code words which occur more frequently in a typical transmission interval and which consist of a second number of bits smaller than the said first number, each code word including a characteristic bit indicating whether the code word belongs to said majority or said minority of code words; main storing means connected to said signal converter means and adapted for receiving during each channel period one code word converted from a signal received from the main input circuits; auxiliary storing means connected to said signal converter means and adapted for receiving code words therefrom converted from signals received from the auxiliary input circuits; output means connected to said main and auxiliary storing means and to said transmission means for receiving code words from said main and auxiliary storing means and delivering the code words to said transmission means; control circuit means, controlled by said main storing means and said pulse generating means for controlling the transfer of signals from the auxiliary input circuits to said signal converter means and the transfer of code words from said signal converter means to said auxiliary storing means and for controlling thE transfer of the bits of the code words from said main and said auxiliary storing means so that during one channel period either the bits of a code word from one of said main input circuits belonging to said minority of signals, or the bits of a code word from one of said main input circuits belonging to said majority of signals and bits of a code word from one of said auxiliary input circuits are transmitted from said output means to said transmission means; auxiliary counter means, responsive to said characteristic bit of the code words which belong to said minority of code words, for counting said code words and for cooperating with said control circuit means to control the transfer of signals from said auxiliary input circuit to said signal converter means; and receiver circuit means connected to said transmission means and to said output lines and operative to provide output signals at said output lines in accordance with said input signals.

Claim 10

A system for digital time multiplex transmission comprising in combination: a plurality of main and auxiliary input lines and of corresponding main and auxiliary output lines; a transmitter having a plurality of main and auxiliary input circuits each connected to one of said main and auxiliary input lines respectively for receiving and storing input signals from each of these input lines separately; pulse generating means delivering slot pulses each defining one time slot, and channel period pulses each defining one channel period; each main input circuit being assigned to one of said channel periods; signal converter means connected to said main input circuits for receiving during each channel period a signal representing the information to be transmitted from one of said main input circuits selected by the channel period pulse assigned thereto, said converter means being further connected to said auxiliary input circuits for receiving signals representing the information to be transmitted therefrom and for converting the received signals into corresponding code words, to be transmitted; the code words being divided into two groups, one group consisting of a majority of the code words which occur less frequently in a typical transmission interval and which consist of a number of bits not greater than the number of time slots within one channel period, and a second group consisting of a minority of code words which occur more frequently in a typical transmission interval and which consist of a second number of bits smaller than the said first number, each code word including a characteristic bit indicating whether the code word belongs to said majority or said minority of code words; main storing means connected to said signal converter means and adapted for receiving during each channel period one code word converted from a signal received from the main input circuits; auxiliary storing means connected to said signal converter means and adapted for receiving code words therefrom converted from signals received from the auxiliary input circuits; output means connected to said main and auxiliary storing means and to said transmission means for receiving code words from said main and auxiliary storing means and delivering the code words to said transmission means; control circuit means, controlled by said main storing means and said pulse generating means for controlling the transfer of signals from the auxiliary input circuits to said signal converter means and the transfer of code words from said signal converter means to said auxiliary storing means and for controlling thE transfer of the bits of the code words from said main and said auxiliary storing means so that during one channel period either the bits of a code word from one of said main input circuits belonging to said minority of signals, or the bits of a code word from one of said main input circuits belonging to said majority of signals and bits of a code word from one of said auxiliary input circuits are transmitted from said output means to said transmission means; auxiliary counter means, responsive to said characteristic bit of the code words which belong to said minority of code words, for counting said code words and for cooperating with said control circuit means to control the transfer of signals from said auxiliary input circuit to said signal converter means; and receiver circuit means connected to said transmission means and to said output lines and operative to provide output signals at said output lines in accordance with said input signals.