Video and data distribution module with subscriber terminal

• US 4,430,731 A
• Filed: 04/29/1981
• Issued: 02/07/1984
• Est. Priority Date: 04/30/1980
• Status: Expired due to Term

• Current Assignee: The Manitoba Telephone System
• Original Assignee: The Manitoba Telephone System
• Inventors: Rodman, William, Gimple, Irving
• Primary Examiner(s): Brigance, Gerald L.
• Application Number:
  US06/258,746
• Time in Patent Office: 1,014 Days
• Field of Search: 370/124, 370/69.1, 370/71, 370/73, 370/85, 370/112, 370/29, 370/120, 370/30, 370/50, 370/26, 179/2 DP, 358/84, 358/85, 375/8
• US Class Current: 725/131
• CPC Class Codes: H04M 11/068 using time division multiplex techniques; integrated services digital networks H04Q11/0428
• CPC Class Codes: H04N 2007/17372 the upstream transmission being initiated or timed by a signal from upstream of the user terminal
• CPC Class Codes: H04N 7/17354 in an intermediate station common to a plurality of user terminals

Abstract

A subscriber data distribution system comprising first means for translating data received from a transmission line and transmitting the data to a subscriber terminal via a subscriber drop, second means for translating data received from a subscriber terminal and transmitting the data to the transmission line, the first and second means including means for isolating the transmission line from the subscriber terminal, and for regenerating the data transmitted both to and from the subscriber terminal.

Claims

1. A subscriber communication terminal comprising:

(a) a modem for receiving incoming data signals from an incoming carrier having a first frequency, for deriving a bit clock signal from the incoming carrier, for generating an outgoing carrier from the incoming carrier and for transmitting outgoing data signals on the outgoing carrier,

(b) the incoming data signals being in the form of frames of data bits, each frame being divided into channels of a predetermined number of bits and ending with an extra frame bit, the frame bits form a predetermined pattern, control signals being contained in a predetermined channel,

(c) a first shift register connected in a circuit with the modem for receiving the data signals,

(d) means for enabling the shift register during the time of the predetermined channel whereby the control signals are read into and stored in the shift register during the time of the predetermined channel,

(e) a bus system for receiving the control signals from the shift register,

(f) means for receiving the bit clock signal and for generating frame and channel count timing signals therefrom,

(g) a second shift register connected to the bus system for receiving outgoing data signals,

(h) a circuit including a switch for carrying the outgoing data signals to the modem for modulation on the outgoing carrier,

(i) a time slot generator adapted to receive the timing signals for generating control signals for said switch and for the second shift register, for controlling the time of application of said outgoing data signals in a predetermined outgoing channel,

(j) port means connected to the bus system for connecting to at least one of data generating and receiving apparatus, and

(k) a microprocessor connected to the bus system for receiving the incoming data signals, generating control signals, reading signals from the port means and writing signals to the port means, and generating said outgoing data signals.

2. A communications terminal as defined in claim 1, in which said circuit including said switch includes a controllable delay means adapted under control of the microprocessor to delay outgoing data signals a time sufficient to synchronize said incoming and outgoing data signals at a remote location.

3. A communications terminal as defined in claim 1 or 2 in which the incoming and outgoing carrier signals are at different frequencies carried by a subscriber drop.

4. A communications terminal as defined in claim 1 or 2 in which the incoming and outgoing carrier signals are at different frequencies carried by a coaxial cable subscriber drop.

5. A communications terminal as defined in claim 2 in which the incoming and outgoing carrier signals are at different frequencies carried by a coaxial cable subscriber drop the subscriber drop also carrying CATV television signals, and further including means for connecting a television set to the subscriber drop with the modem.

6. A communications terminal as defined in claim 5, further including means for connection to one of said ports for generating television channel selection control signals, for transmission via the outgoing carrier to a remote television channel converter, for control of a CATV channel transmitted along the subscriber drop for reception by the television set.

7. A communications terminal as defined in claim 6, in which at least one of said ports is a master UART, having an asynchronous bus output for connection to a remote UART, said remote UART comprising means for connection to said television channel selection control signal generator.

8. A digital data transmission system comprising a central station including means for transmitting and receiving digital data signals in a format having a series of frames each having a plurality of time slots and each time slot having a plurality of bits, a plurality of remote subscriber terminal units each including means for transmitting and receiving digital data signals in said format, a plurality of remote receiving stations, each receiving station having connected thereto a plurality of said subscriber terminal units, and tree-type transmission means interconnecting said central station with each of said receiving stations, each receiving station including means for receiving digital data signals in said format from said central station and from said subscriber terminal units connected thereto and for regenerating from said received data signals new data signals in said format and means for transmitting said new data signals to said subscriber terminal units and to said central station respectively.

9. A system as defined in claim 8 wherein said transmitting means includes means for scanning each of the subscriber terminal units in sequential time slots and means for transmitting said data signals to respective subscriber terminal units in time slots allocated thereto.

10. A system as defined in claim 8 wherein the format includes data signals designated as address, data and control signals, wherein the transmission means of each receiving station includes means for stripping of the control signals and integrating new control signals with regenerated data signals, and means for transmitting the new control signals and regenerating data signals to designated ones of said subscriber terminal units.

11. A system as defined in claim 10, including means for modulating the regenerated data signals and new control signal, on an outgoing carrier for transmission to the subscriber terminal units, the outgoing carrier being derived from the incoming carrier.

12. A system as defined in claim 8, wherein each said receiving station includes means for receiving data signals from the individual subscriber terminal units modulated on a second carrier each during the predetermined time slots, means for demodulating the second carrier to derive demodulated data bits, means for applying the demodulated data bits to a controller, the controller being adapted to reformat the demodulated data bits and to write them at first predetermined times designated by the controller into a memory, means for reading the memory at times delayed from the first predetermined times, and means for applying the data from the memory to a modem for modulation on an outgoing carrier and application to the transmission means, the delay being predetermined to place the outgoing data in bit synchronization and in a predetermined frame with the incoming data at a remote location connected to the transmission line.

13. A system as defined in claim 12 further including a plurality of television channel converters having inputs connected to the transmission means for reception of CATV signals, individual outputs thereof connected to corresponding subscriber terminal units, control inputs of the converter being connected to the receiving stations for controlling individual channels applied to the subscriber terminal units upon reception of a converter selection control signal from a corresponding subscriber terminal unit.

14. A system as defined in claim 8 in which each subscriber terminal unit is comprised of:

(a) a modem for receiving data signals modulated on an incoming carrier having a first frequency, for deriving a bit clock signal from the incoming carrier and for transmitting data signals on an outgoing carrier having a second frequency,

(b) means for applying the received data signals to a bus system.

(c) means for connecting a plurality of ports to the bus system, the ports being adapted to connect data generating apparatus to the bus system, when enabled,

(d) control means connected to the bus system and to the means for connecting a plurality of ports for controlling the operation of the ports, and for generating said outgoing data signals in response to the application of control signals from the ports generating by said data generating apparatus to the bus system, in synchronization with said bit clock, and

(e) means for applying outgoing data signals to the modem for modulation on the outgoing carrier.

15. A system as defined in claim 14, in which the means for connecting a plurality of ports to the bus system is comprised of a plurality of switches enabled from the bus system under control of the control means.

16. A system as defined in claim 15, further including a codec connected in a circuit to the modem for received data signals therefrom, a subscriber line interface circuit connected to the codec and having a tip and ring lead for connection to a telephone set, means for detecting supervisory signals generated by a telephone set connected between the tip and ring lead and a read port connected to the bus system, and a write port connected between the bus system and the subscriber line interface system for generating ringing signals for application to the tip and ring lead.

17. A system as defined in claim 15, in which said ports are adapted to receive data from at least one of a load activity indicator, an energy meter, a keypad, a keyboard, a telephone supervisory state sensor, a fire alarm, a smoke alarm, and a plurality of burglar alarm switches, and to apply control signals to at least one of a load controller, an alphanumeric and/or illuminated display, telephone control apparatus, and a data terminal.

18. A system as defined in claim 14, in which the means for connecting a plurality of ports to the bus system is comprised of a master UART, having an asynchronous bus connected to a plurality of remote addressable UARTs, further including means for connecting data data generating apparatus to the addressable UARTs.

19. A system as defined in claim 18, in which the means for connecting a plurality of ports further includes at least one write port and at least one read port, the read port being comprised of a plurality of switches enabled from the bus system under control of the control means, the write port being under control of the control means for receiving data addressed to the write port and applying said data to a terminal including are of means for display of and control by said data addressed to the write port.

20. A system as defined in claim 14, in which the transmitting means of each receiving station is arranged to transmit data in a predetermined time slot unique to the respective terminal in one frame of said format, and in which the transmitting means of said respective terminal unit is arranged to transmit data in the same time slot and the same frame number of a later following sequence of frames.

21. A system as defined in claim 20, wherein each terminal unit includes means for storing the data for transmission for a controllable period of time, means for applying said data to the storing means via a switch, means under control of the controlling means for generating time slot controlling signals, and for applying the time slot controlling signals to the switch for controlling the application of the data to the storing means within predetermined time slot periods, and means for setting the storage time sufficient to delay the data to a period whereby it arrives at the receiving station in the same time slot and frame number.

22. A system as defined in claim 21, in which the data signals are divided into frames of data words, and including a sequence of fame bits, the frame bits having a predetermined bit pattern, the data signals including control signals in a predetermined frame, means for applying the control signals to the bus system when strobed by the bit clock and by signals designating the predetermined frame, means for deriving bits from the bit clock at a frame bit rate, means for comparing the derived bit pattern with a predetermined pattern stored in the control means, means for shifting the derived frame bit rate by one bit in the event the derived bit pattern does not match the predetermined pattern, means for counting frame bits to derive a frame count, and means for generating said time slot controlling signals from the means for deriving bits from the bit clock and the means for counting frame bits.

23. A system as defined in claim 14, in which each subscriber terminal is comprised of:

(a) a modem for receiving data signals from an incoming carrier having a first frequency, for deriving a bit clock signal from the incoming carrier, for generating an outgoing carrier from the incoming carrier and for transmitting outgoing data signals on the outgoing carrier,

(b) the incoming data signals being in the form of frames of data bits, each frame being divided into channels of a predetermined number of bits and ending with an extra frame bit, the frame bits form a predetermined pattern, control signals being contained in a predetermined channel,

(c) a first shift register connected in a circuit with the modem for receiving the data signals,

(d) means for enabling the shift register during the time of the predetermined channel whereby the control signals are read into and stored in the shift register during the time of the predetermined channel,

(e) a bus system for receiving the control signals from the shift register,

(f) means for receiving the bit clock signal and for generating frame and channel count timing signals therefrom,

(g) a second shift register connected to the bus system for receiving outgoing data signals,

(h) a circuit including a switch for carrying the outgoing data signals to the modem for modulation on the outgoing carrier,

(i) a time slot generator adapted to receive the timing signals for generating control signals for said switch and for the second shift register, for controlling the time of application of said outgoing data signals in a predetermined outgoing channel,

(j) port means connected to the bus system for connection to at least one of data generating and receiving apparatus, and

(k) a microprocessor connected to the bus system for receiving the incoming data signals, generating control signals, reading signals from the port means and writing signals to the port means, and generating said outgoing data signals.

24. A system as defined in claim 23 in which said circuit including said switch includes a controllable delay means adapted under control of the microprocessor to delay outgoing data signals a time sufficient to synchronize data signals transmitted and received by said receiving station.

25. A system as defined in claim 24 in which the incoming and outgoing carrier signals are at different frequencies carried by a coaxial cable subscriber drop, the subscriber drop also carrying CATV television signals, and further including means for connecting a television set to the subscriber drop with the modem.

26. A system as defined in claim 25 further including means for connection to one of said ports for generating television channel selection control signals, for transmission via the outgoing carrier to a remote television channel converter, for control of a CATV channel transmitted along the subscriber drop for reception by the television set.

27. A system as defined in claim 26 in which at least one of said ports is a master UART, having an asynchronous bus output for connection to a remote UART, said remote UART comprising means for connection to said television channel selection control signal generator.