SLC-96 plug-in multiplexer

• US 5,917,814 A
• Filed: 03/20/1995
• Issued: 06/29/1999
• Est. Priority Date: 03/20/1995
• Status: Expired due to Fees

• Current Assignee: Terayon Communications Systems Incorporated (Motorola Solutions, Inc.)
• Original Assignee: Raychem Corporation (TE Connectivity Limited)
• Inventors: Balatoni, Nicholas A.
• Primary Examiner(s): TON, DANG T
• Application Number:
  US08/408,020
• Time in Patent Office: 1,562 Days
• Field of Search: 370/58.1, 370/112, 370/60, 370/60.1, 370/94.1, 370/94.2, 370/94.3, 370/85.13, 370/85.1, 370/58.2, 370/29, 370/31, 370/32, 370/58.3, 370/118, 370/110.1, 370/66 , 370/11, 370/42, 370/77, 370/67, 370/81, 370/80, 370/68, 370/76, 370/111, 370/294, 370/280, 370/351, 370/352, 370/359, 370/357, 370/355, 370/376, 370/375, 370/387, 370/388 , 370/386, 370/377, 370/342, 370/442, 370/420, 370/522, 370/524, 370/276, 370/296, 379/210, 379/93, 379/157, 379/201, 379/14, 379/15, 379/33, 379/1, 379/27, 379/333, 379/32, 379/335, 379/339, 375/357, 375/362
• US Class Current: 370/352
• CPC Class Codes: H04Q 11/04 for time-division multiplexing H04Q11/0001 takes precedence

Abstract

A system for use with a subscriber line carrier such as a SLC-96. The system provides a multiplex channel unit 10 that inputs T1 line signals, and outputs multiple telephone line signals in a format such as 2B1Q over a twisted pair 13 to an RT 35. The RT 35 converts the full duplex multiplexed signals to analog service for a subscriber 12.

Claims

1. A telephony system for transmitting signals to and from a subscriber line comprising:

a subscriber line carrier unit comprising a backplane and a plurality of digital channel unit slots, each diital channel unit slot coupled to said backplane, said backplane coupled to multiple telephone company PCM or PAM lines;

a channel unit in at least one of said digital channel unit slots, said channel unit comprising a multiplexing circuit for converting signals on said PCM or PAM lines to multiplexed, full duplex digital signals for transmission and reception over a single twisted pair; and

a remote terminal at a subscriber location, said remote terminal converting said multiplexed, full duplex digital signals on said single twisted pair to subscriber service for at least two analog, 64 kbits/sec telephone lines at said subscriber location.

2. The system as recited in claim 1 wherein said PCM or PAM lines are T1 lines.

3. The system as recited in claim 1 wherein said PCM or PAM lines are E1 lines.

4. The system as recited in claim 2 wherein four of said T1 lines are input to said subscriber line carrier for generation of 96 subscriber lines.

5. The system as recited in claim 1 further comprising other channel units in said subscriber line carrier unit, said other channel units outputting analog signals to other subscribers over analog twisted pairs.

6. The system as recited in claim 1 wherein said multiplexed full duplex signals are 2B1Q signals.

7. The system as recited in claim 1 wherein said multiplexed full duplex signals are 4B3T signals.

8. The system as recited in claim 1 wherein said subscriber line carrier unit is coupled to a subscriber line central office unit, said subscriber line central office unit inputting analog signals from a central office switch, and outputting said PCM or PAM lines.

9. The system as recited in claim 1 wherein said channel unit comprises:

an interface circuit for interfacing to said backplane of said subscriber line carrier unit;

a first circuit coupled to said interface circuit for inputting segments of T1 signals and outputting duplexed digital time multiplexed signals;

a second circuit coupled to said first circuit for inputting said duplexed digital time multiplexed signals and outputting transmit digital signals;

a third circuit coupled to said second circuit for inputting said transmit digital signals and outputting quaternary signals; and

a line transmission circuit for inputting said quaternary signals and outputting two-wire quaternary signals.

10. The system as recited in claim 9 further comprising a programmable logic device for generating and receiving control signals to and from said backplane.

11. A method of using a subscriber line carrier, said subscriber line carrier comprising a plurality of digital channel unit slots, said digital channel unit slots adapted to receive channel units, said channel units adapted to each generate multiple analog telephony signals and transmit each of said multiple analog telephony line signals over corresponding twisted pair wires, said method comprising the step of installing a multiplex channel unit, said multiplex channel unit transmitting and receiving multiple telephony line signals between said channel unit slots and a subscriber location over a single twisted pair;

and converting said multiple telephony line signals to multiple, 64 kbits/sec analog services provided over multiple twisted pairs at said subscriber location.

12. The method as recited in claim 11 wherein said subscriber line carrier is a SLC 96 and said SLC 96 inputs multiple T1 signals.

13. The method as recited in claim 11 wherein said channel units are adapted to generate two analog telephony line signals for transmission over two corresponding twisted pair wires, and said multiplex channel units are adapted to transmit two telephony line signals over said twisted pair.

14. The method as recited in claim 11 wherein said multiple telephony line signals are transmitted using a 2B1Q line coding standard.

15. The method as recited in claim 11 wherein said multiple telephony line signals are transmitted using a 4B3T line coding standard.

16. The method as recited in claim 12 wherein said T1 signals are generated from multiple analog signals at a central office switch.

17. In a system for single channel transmission from telephone company equipment at a first location to a subscriber location over a twisted pair, a method of converting said system to a system for multiple channel transmission over said twisted pair comprising:

a) installing a multiplexer in the telephone company equipment at the first location, said multiplexer;

i) inputting multiple incoming backplane digital signals from a backplane of the telephone company equipment and outputting multiple outgoing backplane digital signals to the backplane of the telephone company equipment;

ii) converting said multiple incoming backplane digital signals to a multiplexed outgoing 2B1Q digital signal and converting a multiplexed incoming 2B1Q digital signal to said multiple outgoing backplane signals; and

iii) transmitting said multiplexed outgoing 2B1Q digital signal over said twisted pair to said subscriber location and receiving said multiplexed incoming 2B1Q digital signal; and

b) installing a remote terminal at said subscriber location, said remote terminal;

i) inputting said multiplexed outgoing 2B1Q digital signal from said twisted pair and outputting said multiplexed incoming 2B1Q digital signal on said twisted pair;

ii) converting said multiplexed outgoing 2B1Q digital signal to multiple outgoing analog 64 kbits/sec subscriber signals and converting multiple incoming analog 64 kbits/sec subscriber signals to said multiplexed incoming digital signal; and

iii) transmitting said multiple outgoing analog 64 kbits/sec subscriber signals to said subscriber equipment and receiving said multiple incoming analog 64 kbits/sec subscriber signals from said subscriber equipment.

18. The method as recited in claim 17 wherein said multiplexed outgoing digital signal and said multiplexed incoming digital signal comprise quaternary signals.

19. The method as recited in claim 17 wherein the telephone company equipment comprises a SLC-96 remote terminal and installing said multiplexer comprises plugging in said multiplexer into a channel unit shelf space of the SLC-96 remote terminal.

20. The method as recited in claim 19 wherein said single channel and said multiple channels comprise VF channels, and wherein said multiple outgoing subscriber signals and said multiple incoming subscriber signals comprise analog signals.

21. The method as recited in claim 20 wherein said multiple incoming backplane signals and said multiple outgoing backplane signals comprise pulse amplitude modulation (PAM) signals.

22. The method as recited in claim 20 wherein said multiple incoming backplane signals and said multiple outgoing backplane signals comprise pulse code modulation (PCM) signals.

23. The method as recited in claim 19 wherein said single channel and said multiple channels comprise 4-wire digital data service (DDS) channels, and wherein said multiple incoming backplane signals and said multiple outgoing backplane signals comprise digital data bus signals.

24. A method of converting a system providing telephone line service over a single twisted pair into a system providing multiple telephone line service over said single twisted pair, said method comprising:

providing a remote terminal at a subscriber location, said remote terminal including electronics in an enclosure, said electronics coupled to a first twisted pair, a second twisted pair, and a third twisted pair, wherein said enclosure is constructed as a door; and

installing said remote terminal, said installing step including electrically connecting said first twisted pair and said single twisted pair to set up a digital subscriber loop, electrically connecting said second twisted pair to a first customer subscriber wiring to a provide a first telephone line service, and electrically connecting said third twisted pair to a second customer subscriber wiring to provide a second telephone line service.

25. The method as recited in claim 24, said method further comprising:

installing a multiplexer at a telephone company location coupled to said single twisted pair.

26. The method as recited in claim 25, wherein said telephone company location is a SLC-96 remote terminal.

27. The method as recited in claim 24, wherein said installing step further includes using said enclosure as a cover to a network interface device (NID).

28. The method as recited in claim 24, wherein said installing step further includes removing an existing door from said network interface device.

29. The method as recited in claim 24, wherein said first and second telephone line services provide voice signals.

30. The method as recited in claim 24, wherein said first and second telephone line services provide data signals.

31. The method as recited in claim 24, wherein said first telephone line service provides voice signals and said second telephone line service provides data signals.

32. The method as recited in claim 24, wherein said remote terminal with said electronics may be replaced by a like remote terminal with different electronics to change the services provided.

33. The method as recited in claim 24, wherein the remote terminal is environmentally protected.

34. The method as recited in claim 24, wherein said remote terminal further includes a base coupled to said enclosure.