Method and apparatus for time division multiplex transmission of binary data

Claim 2

Apparatus for transmitting binary data over a predetermined group of transmission digit time slots of a predetermined channel of a multiple channel time division multiplex transmission system wherein said data is first introduced from a source thereof into said system at an average first digit rate and wherein the long term average digit rate of said predetermined group of transmission digit time slots of said channel exceeds said first digit rate, comprising in combination: a. means including a digit time slot generator and channel counter at the transmitting terminal of said transmission system for generating a time division multiplex transmission format comprised of a plurality of serially arranged transmission channels each having a plurality of consecutively occurring transmission digit time slots of one binary digit each; b. means at the transmitting terminal of said transmission system for storing said data at least until a plurality of data digits thereof is received into said apparatus for transmission over said predetermined channel; c. means at said transmitting terminal responsive to said means (a) for transmitting said stored data in the form of digital bytes comprised of a plurality of said data digits over said predetermined group of transmission digit time slots of said channel on the occurrence of said channel within a time division multiplex frame; d. means at said transmitting terminal for periodically stuffing by transmitting a transmission digit of a predetermined state in At least a first transmission digit slot of said predetermined group of digit time slots of said channel transmitting said data and for providing a stuffing indicating signal in another transmission digit slot of said predetermined group of digit time slots to signal the receiving terminal of said transmission system on each occurrence of said stuffing, said stuffing and signalling being performed at a rate sufficiently high to provide substantially for long term equality between the long term average digit rate of said predetermined group of transmission digits and the sum of said average first digit rate of said data added to said stuffing and signalling rate; e. detecting means at said receiving terminal for detecting said stuffing indicating signal in said other transmission digit slot; and f. means in said receiving terminal responsive to said detecting means (e) for reconstructing said binary data at an average digit rate substantially equal to said first digit rate by recovering the digits of said predetermined group of digits transmitted in said channel less the digits of said first and other transmission digit slots used for said stuffing and signalling.

Claim 3

Apparatus for transmitting binary data over a predetermined channel of a multiple channel time division multiplex transmission system wherein said data is first introduced from a source thereof into said system at an average first digit rate and wherein the long term average digit rate of said predetermined channel exceeds said first digit rate, comprising in combination: a. means including a digit time slot generator and channel counter at the transmitting terminal of said transmission system for generating a time division multiplex transmission format comprised of a plurality of serially arranged transmission channels each having a plurality of consecutively occurring transmission digit time slots of one binary digit each; b. means at the transmitting terminal of said transmission system for storing said data at least until a plurality of digits thereof is received into said apparatus for transmission over said predetermined channel; c. means at said transmitting terminal responsive to said means (a) for transmitting said stored data in the form of digital bytes comprised of a plurality of said data digits over said predetermined channel on the occurrence of said channel within a time division multiplex frame; d. means at said transmitting terminal for periodically stuffing by transmitting a transmission digit of a predetermined state in at least a first transmission digit slot of said predetermined channel transmitting said data and for providing a stuffing indicating signal in another transmission digit slot of said channel to signal the receiving terminal of said transmission system on each occurrence of said stuffing, said stuffing and signalling being performed at a rate sufficiently high to provide substantially for long term equality between the long term average digit rate of said channel and the sum of said average first digit rate of said data added to said stuffing and signalling rate; e. means at said receiving terminal for storing the received digits of said channel at least until the entire byte of said channel is received; f. means at said receiving terminal coupled with said storing means (e) for detecting said stuffing indicating signal in said other transmission digit slot; and g. means at said receiving terminal responsive to said detecting means (f) for reconstructing said binary data at an average recovery digit rate substantially equal to said first digit rate by reading out of said storing means (e) at said recovery digit rate said received digits of said channel less the respective digits of said first and other transmission digit slots used for said stuffing and signalling.

Claim 4

Apparatus for transmitting binary data over a predetermined channel of a multiple channel time division multiplex transmission system wherein said data is first introduced from a source thereof into said system at an average first digit rate and wherein the long term average digit rate of said predetermined channel exceeds said first digit rate, comprising in combination: a. means including a digit time slot generator and channel counter at the transmitting terminal of said transmission system for generating a time division multiplex transmission format comprised of a plurality of serially arranged transmission channels each having a plurality of consecutively occurring transmission digit time slots of one binary digit each; b. means at the transmitting terminal of said transmission system for storing said data at least until a plurality of digits thereof is received into said apparatus for transmission over said predetermined channel; c. means at said transmitting terminal responsive to said means (a) for transmitting said stored data in the form of digital bytes comprised of a plurality of said data digits over said predetermined channel on the occurrence of said channel within a time division multiplex frame; d. means at said transmitting terminal for periodically stuffing by transmitting a transmission digit of a predetermined state in at least a first transmission digit slot of said predetermined channel transmitting said data and for providing a stuffing indicating signal in another transmission digit slot of said channel to signal the receiving terminal of said transmission system on each occurrence of said stuffing, said stuffing and signalling being performed at a rate sufficiently high to provide substantially for long term equality between the long term average digit rate of said channel and the sum of said average first digit rate of said data added to said stuffing and signalling rate; e. means at said receiving terminal for storing the received digits of said channel at least until the entire byte of said channel is received; f. means at said receiving terminal coupled with said storing means (e) for detecting said stuffing indicating signal in said other transmission digit slot; and g. means at said receiving terminal responsive to said detecting means (f) for reconstructing said binary data at an average recovery digit rate substantially equal to said first digit rate by reading out of said storing means (e) at said recovery digit rate said received digits of said channel less the respective digits of said first and other transmission digit slots used for said stuffing and signalling.

Claim 5

Apparatus for transmitting binary data over a predetermined channel of a multiple channel time division multiplex transmission system wherein said data is first iNtroduced from a source thereof into said system at an average first digit rate and wherein the long term average digit rate of said predetermined channel exceeds said first digit rate, comprising in combination: a. means including a digit time slot generator and channel counter at the transmitting terminal of said transmission system for generating a time division multiplex transmission format comprised of a plurality of serially arranged transmission channels each having a plurality of consecutively occurring transmission digit time slots of one binary digit each; b. means at the transmitting terminal of said transmission system for storing said data at least until a plurality of digits thereof is received from said source for transmission over said predetermined channel; c. means at said transmitting terminal responsive to said means (a) for transmitting said stored data in the form of digital bytes comprised of a plurality of said data digits over said predetermined channel on the occurrence of said channel within a time division multiplex frame; d. means at said transmitting terminal operatively coupled with said means (b) and (c) for reading prior to transmission thereof said binary data out of said storing means (b) in the form of said digital bytes and at an instantaneous digit read-out rate substantially equal to said long term average digit rate of said channel; e. means at said transmitting terminal operatively coupled with said reading means (d) for periodically stuffing said bytes provided by said reading means (d) by periodically inserting therein a first digit of predetermined state, and for providing a stuffing indicating signal by inserting therein a second digit of predetermined state on each occurrence of said stuffing, said stuffing means (e) including means for performing said stuffing and signal inserting at a rate sufficiently high to provide substantially for a long term equality between said long term average digit rate of said channel and the sum of said average first digit rate of said data added to said stuffing and signal inserting rate, said stuffing means (e) including further means for arranging said inserted first and second digits in said bytes in predetermined order to respectively occupy predetermined first and second transmission digit time slots of said predetermined transmission channel; f. means at said receiving terminal for storing the received digits of said channel at least until the entire byte of said channel is received; g. means at said receiving terminal coupled with said storing means (f) for detecting said stuffing indicating signal in said second transmission digit time slot; and h. means at said receiving terminal responsive to said detecting means (g) for reconstructing said binary data at an average recovery digit rate substantially equal to said first digit rate by reading out of said storing means (f) at said recovery digit rate said received digits of said channel less the digits used for said stuffing and signalling.

Claim 6

Apparatus for transmitting binary data over a predetermined channel of a multiple channel time division multiplex transmission system wherein said data is first iNtroduced from a source thereof into said system at an average first digit rate and wherein the long term average digit rate of said predetermined channel exceeds said first digit rate, comprising in combination: a. means including a digit time slot generator and channel counter at the transmitting terminal of said transmission system for generating a time division multiplex transmission format comprised of a plurality of serially arranged transmission channels each having a plurality of consecutively occurring transmission digit time slots of one binary digit each; b. means at the transmitting terminal of said transmission system for storing said data at least until a plurality of digits thereof is received from said source for transmission over said predetermined channel; c. means at said transmitting terminal responsive to said means (a) for transmitting said stored data in the form of digital bytes comprised of a plurality of said data digits over said predetermined channel on the occurrence of said channel within a time division multiplex frame; d. means at said transmitting terminal operatively coupled with said means (b) and (c) for reading prior to transmission thereof said binary data out of said storing means (b) in the form of said digital bytes and at an instantaneous digit read-out rate substantially equal to said long term average digit rate of said channel; e. means at said transmitting terminal operatively coupled with said reading means (d) for periodically stuffing said bytes provided by said reading means (d) by periodically inserting therein a first digit of predetermined state, and for providing a stuffing indicating signal by inserting therein a second digit of predetermined state on each occurrence of said stuffing, said stuffing means (e) including means for performing said stuffing and signal inserting at a rate sufficiently high to provide substantially for a long term equality between said long term average digit rate of said channel and the sum of said average first digit rate of said data added to said stuffing and signal inserting rate, said stuffing means (e) including further means for arranging said inserted first and second digits in said bytes in predetermined order to respectively occupy predetermined first and second transmission digit time slots of said predetermined transmission channel; f. means at said receiving terminal for storing the received digits of said channel at least until the entire byte of said channel is received; g. means at said receiving terminal coupled with said storing means (f) for detecting said stuffing indicating signal in said second transmission digit time slot; and h. means at said receiving terminal responsive to said detecting means (g) for reconstructing said binary data at an average recovery digit rate substantially equal to said first digit rate by reading out of said storing means (f) at said recovery digit rate said received digits of said channel less the digits used for said stuffing and signalling.

Claim 7

The apparatus of claim 3 wherein said apparatus includes means for providing N transmission digit time slots in said channel and wherein said stuffing means (e) comprises: e. a shift register including at least N series connected stages the first stage of which is connected with said read-out means (d) for accepting said data read-out thereof; means for shifting said register at a rate equal to said digit read-out rate to advance the digits of said data to successive stages of said register; means for periodically discharging said shift register of its contents in the form of said digital bytes comprised of N digits for transmission; means for stuffing the (N-1)th stage of said register by providing a high state therein and for providing a zero in the Nth stage on each said occurrence of said stuffing to provide said stuffing in the form of a stuffed high (N-1)th transmission digit slot of said channeL and to provide said signal in the form of a zero in the Nth transmission digit slot of said channel; and means for stuffing high the Nth stage of said register for each byte of said channel which is not subjected to said sufficiently frequent stuffing whereby said Nth transmission digit slot of said channel is normally transmitted stuffed high and when said stuffing occurs in said (N-1)th transmission digit slot said receiving terminal is signalled thereof by a zero in said Nth transmission digit slot.

Claim 8

The apparatus of claim 4 wherein said detecting means (g) in said receiving terminal includes a bistable circuit connected therein to receive said Nth transmission digit slot to assume a first state in response to a zero in said Nth transmission digit slot and to assume a second state in response to a stuffed Nth transmission digit slot; and wherein said reconstructing means (h) at said receiving terminal comprises: h. a shift register including at least N-1 series connected stages connected with said storing means (f) for each of said stages to accept a received digit of said channel less the digit of said Nth digit slot; means for shifting said received digits out of said register at a digit rate at least equal to the average digit rate of N-1 digits of said channel to provide a serial output digital signal; and means responsive to said bistable circuit for inhibiting the shifting of the digit of said (N-1)th transmission digit slot out of said shift register when said bistable circuit is in its first state whereby said output of said shift register is caused to exclude said (N-1)th digit on each occurrence thereof in said stuffed condition, whereby the digits of said shift register output signal correspond to the digits of said binary data as introduced into said apparatus for transmission.

Claim 9

Apparatus for transmitting binary data digits in the form of digital bytes comprised of a plurality of said data digits over a predetermined channel of a multiple channel time division multiplex transmission system wherein said binary data is first introduced from a source thereof into said system at an average first digit rate and wherein the long term average digit rate of said predetermined channel exceeds said first digit rate, comprising in combination: a. means including a digit time slot generator and channel counter at the transmitting terminal of said transmission system for generating a time division multiplex transmission format comprised of a plurality of serially arranged transmission channels each having a plurality of consecutively occurring transmission digit slots of one binary digit each; b. storage means at the transmitting terminal of said transmission system for storing said data at least until a plurality of digits thereof is received from said source for transmission over said predetermined channel; c read-out means at said transmitting terminal for reading out of said storage means (b) in serial form said binary data at an instantaneous digit read-out rate substantially equal to said average digit rate of said channel; d. inhibit means at said transmitting terminal for periodically inhibiting said read-out means (c) for substantially the time interval of one digit of said read-out rate, said inhibiting being performed sufficiently frequent to provide an average effective read-out rate of said data substantially equal to said first digit rate; e. means including a shift register at said transmitting terminal coupled to said read-out means and said inhibit means for registering said read-out data and for releasing it in the form of said data bytes for transmission over said channel; f. means associated with said shift register responsive to said inhibit means for stuffing a first transmission digit slot of said data byte by inserting a first digit of predetermined state and for providing a stuffing indicating signal by inserting a second digit of predetermined state in another transmission digit slot of said byte on each occurrence of said inhibiting; g. means including a plurality of transmission gates at said transmitting terminal for transmitting said data bytes including said first and second digits over said predetermined channel; h. means at the receiving terminal of said transmission system for storing the received digits of said channel at least until the entire byte of said channel is received; i. detecting means at said receiving terminal for detecting said stuffing indicating signal in said other transmission digit slot; j. read-out means at said receiving terminal for reading out of said storing means (h) said received channel byte less said other digit slot at a read-out rate substantially equal to said average digit rate of said channel; k. means at said receiving terminal responsive to said detecting means (i) for inhibiting said read-out means (j) from reading out said stuffed first digit slot of said byte in response to said indicating signal in said other digit slot, whereby the average read-out rate of said means (j) is substantially equal to said first digit rate; and l. output means at said receiving terminal coupled with said read-out means (j) for providing an output binary data signal at a digit rate substantially equal to said first digit rate thereby corresponding to said binary data introduced into said system for transmission.

Claim 10

Apparatus for transmitting binary data digits in the form of digital bytes comprised of a plurality of said data digits over a predetermined channel of a multiple channel time division multiplex transmission system wherein said binary data is first introduced from a source thereof into said system at an average first digit rate and wherein the long term average digit rate of said predetermined channel exceeds said first digit rate, comprising in combination: a. means including a digit time slot generator and channel counter at the transmitting terminal of said transmission system for generating a time division multiplex transmission format comprised of a plurality of serially arranged transmission channels each having a plurality of consecutively occurring transmission digit slots of one binary digit each; b. storage means at the transmitting terminal of said transmission system for storing said data at least until a plurality of digits thereof is received from said source for transmission over said predetermined channel; c read-out means at said transmitting terminal for reading out of said storage means (b) in serial form said binary data at an instantaneous digit read-out rate substantially equal to said average digit rate of said channel; d. inhibit means at said transmitting terminal for periodically inhibiting said read-out means (c) for substantially the time interval of one digit of said read-out rate, said inhibiting being performed sufficiently frequent to provide an average effective read-out rate of said data substantially equal to said first digit rate; e. means including a shift register at said transmitting terminal coupled to said read-out means and said inhibit means for registering said read-out data and for releasing it in the form of said data bytes for transmission over said channel; f. means associated with said shift register responsive to said inhibit means for stuffing a first transmission digit slot of said data byte by inserting a first digit of predetermined state and for providing a stuffing indicating signal by inserting a second digit of predetermined state in another transmission digit slot of said byte on each occurrence of said inhibiting; g. means including a plurality of transmission gates at said transmitting terminal for transmitting said data bytes including said first and second digits over said predetermined channel; h. means at the receiving terminal of said transmission system for storing the received digits of said channel at least until the entire byte of said channel is received; i. detecting means at said receiving terminal for detecting said stuffing indicating signal in said other transmission digit slot; j. read-out means at said receiving terminal for reading out of said storing means (h) said received channel byte less said other digit slot at a read-out rate substantially equal to said average digit rate of said channel; k. means at said receiving terminal responsive to said detecting means (i) for inhibiting said read-out means (j) from reading out said stuffed first digit slot of said byte in response to said indicating signal in said other digit slot, whereby the average read-out rate of said means (j) is substantially equal to said first digit rate; and l. output means at said receiving terminal coupled with said read-out means (j) for providing an output binary data signal at a digit rate substantially equal to said first digit rate thereby corresponding to said binary data introduced into said system for transmission.

Claim 11

The apparatus of claim 6 wherein said binary data is sequentially received in said apparatus at said average first digit rate, wherein said read-out means (c) include; a clock signal generating circuit for generating a series of timed pulses the repetition rate of which is substantially equal to said average digit rate of said channel, a ring counter coupled with said clock circuit and having a high state preset in one stage driven around said ring counter by said clock circuit, and gateing means operatively coupled with said storage means (b) and coupled with said ring counter responsive to said driven preset high for sequentially reading said data out of said storing means (b) at said digit rate of said channel; and wherein said inhibit means (d) include; an inhibit gate coupled with said ring counter for periodically inhibiting said data reading by said counter for one digit of said reading out, and means for applying an inhibit signal to said inhibit gate sufficiently frequent to provide said average effective read-out rate of said data by said counter.

Claim 12

The apparatus of claim 7 wherein said storing means (h) in said receiving terminal include a plurality of parallel storage stages connected in said receiving terminal for each to receive and store a received digit of said channel, said plurality of storage stages being sufficient in number to store the entire byte transmitted in said channel less the digit of said other signalling digit slot, wherein said read-out means (j) in said receiving terminal include; a receiver clock signal generating circuit for generating a series of timed pulses the repetition rate of which is substantially equal to said average digit rate of said channel, and a series connected shift register including a plurality of stages equal in number to the number of said storage stages wherein each said register stage is connected with a storage stage to read therefrom said stored digits, wherein said shift register is driven by said receiver clock to read-out of said storage stages in serial form said received binary data at said instantaneous digit read-out rate and wherein said shift register is connected with said inhibit means (k) for inhibiting said shift register from shifting into said serial output thereof said stuffed first transmission digit slot in response to said detecting means.