Communication server apparatus and method

• US 5,668,857 A
• Filed: 03/29/1996
• Issued: 09/16/1997
• Est. Priority Date: 03/29/1996
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: NetSpeed, Inc. (Cisco Systems, Inc.)
• Inventors: McHale, John F.
• Primary Examiner(s): WOO, STELLA L
• Application Number:
  US08/625,769
• Time in Patent Office: 536 Days
• Field of Search: 379/98, 379/93, 379/94, 379/97, 348/6, 348/7, 348/12, 348/13, 348/14, 348/17, 348/16, 375/222, 375/220
• US Class Current: 379/93.07
• CPC Class Codes: H04L 12/2856 Access arrangements, e.g. Internet access asynchronous transfer mode networks H04L12/5601; broadband local area networks H04L12/2801; optical access or distribution networks H04Q11/0067; access to open networks H04L12/5691; digital subscriber line end-user equipment and bit-level processing of data on a PSTN-based network H04M11/00; home network gateways H04L12/2834; wireless access networks H04W
• CPC Class Codes: H04L 12/2889 Multiservice, e.g. MSAN
• CPC Class Codes: H04L 12/4612 LAN interconnection over narrowband networks, e.g. N-ISDN, PSTN, X.25
• CPC Class Codes: H04L 12/5692 Selection among different networks
• CPC Class Codes: H04L 27/0008 arrangements for allowing a transmitter or receiver to use more than one type of modulation negotiating modulation type for two-way transmission paths H04L5/1453
• CPC Class Codes: H04M 11/06 Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
• CPC Class Codes: H04M 11/062 using different frequency bands for speech and other data
• CPC Class Codes: H04Q 11/0421 Circuit arrangements therefor
• CPC Class Codes: H04Q 2213/13003 Constructional details of switching devices
• CPC Class Codes: H04Q 2213/1302 Relay switches
• CPC Class Codes: H04Q 2213/13036 Serial/parallel conversion, parallel bit transmission
• CPC Class Codes: H04Q 2213/13039 Asymmetrical two-way transmission, e.g. ADSL, HDSL
• CPC Class Codes: H04Q 2213/1304 Coordinate switches, crossbar, 4/2 with relays, coupling field
• CPC Class Codes: H04Q 2213/13093 Personal computer, PC
• CPC Class Codes: H04Q 2213/13103 Memory
• CPC Class Codes: H04Q 2213/13106 Microprocessor, CPU
• CPC Class Codes: H04Q 2213/13109 Initializing, personal profile
• CPC Class Codes: H04Q 2213/1319 Amplifier, attenuation circuit, echo suppressor
• CPC Class Codes: H04Q 2213/13196 Connection circuit/link/trunk/junction, bridge, router, gateway
• CPC Class Codes: H04Q 2213/13199 Modem, modulation
• CPC Class Codes: H04Q 2213/13203 : Exchange termination [ET]
• CPC Class Codes: H04Q 2213/13204 : Protocols
• CPC Class Codes: H04Q 2213/13213 : Counting, timing circuits
• CPC Class Codes: H04Q 2213/1329 : Asynchronous transfer mode, ATM
• CPC Class Codes: H04Q 2213/13292 : Time division multiplexing, TDM
• CPC Class Codes: H04Q 2213/13299 : Bus
• CPC Class Codes: H04Q 2213/13302 : Magnetic elements
• CPC Class Codes: H04Q 2213/1332 : Logic circuits
• CPC Class Codes: H04Q 2213/13322 : Integrated circuits
• CPC Class Codes: H04Q 2213/1334 : Configuration within the switch
• CPC Class Codes: H04Q 2213/13349 : Network management
• CPC Class Codes: H04Q 2213/13389 : LAN, internet

Abstract

A communication system (10) includes a number of subscribers (12) coupled to a central office (14) using twisted pair subscriber lines (16). The central office (14) includes a telephone switch (56) that provides telephone service to the subscribers (12), and a communication server (58) having a plurality of XDSL modems (160) that provide data service to the subscribers (12). The communication server (58) allows over-subscription of data service to subscribers (12).

Claims

1. A communication system, comprising:

a plurality of computers located at a plurality of subscriber premises, each computer having a first XDSL modem to communicate information;

a plurality of twisted pair subscriber lines coupled to the plurality of computers, each twisted pair subscriber line forming a local loop;

a splitter remotely located from the plurality of subscriber premises and coupled to the local loops formed by the twisted pair subscriber lines, the splitter to split each twisted pair subscriber line into a twisted pair data line and a twisted pair phone line; and

a communication server coupled to the twisted pair data lines of the splitter, the communication server having a plurality of second XDSL modems to communicate information with the first XDSL modems using the twisted pair subscriber lines and associated twisted pair data lines, the communication server to couple the second XDSL modems to selected subsets of the twisted pair data lines, wherein the first XDSL modems at the subscriber premises and the second XDSL modems at the communication server provide high bandwidth data service using the twisted pair subscriber lines.

2. The communication system of claim 1, further comprising a telephone switch coupled to the twisted pair phone lines of the splitter, the telephone switch operable to provide telephone service to the subscriber premises using the twisted pair subscriber lines and associated twisted pair phone lines.

3. The communication system of claim 2, further comprising a plurality of telephone located at the subscriber premises and coupled to the twisted pair subscriber lines, each telephone operable to receive telephone service provided by the telephone switch.

4. The communication system of claim 1, further comprising a plurality of second splitters located at the subscriber premises, each second splitter operable to split each twisted pair subscriber line into a twisted pair data line and a twisted pair phone line, the twisted pair data line being coupled to the first XDSL modem.

5. The communication system of claim 1, wherein:

the first XDSL modems are operable to communicate information to the second XDSL modems at a first rate; and

the second XDSL modems are operable to communicate information to the first XDSL modems at a second rate greater than the first rate.

6. The communication system of claim 1, wherein the communication server further comprises:

a switch coupled to the twisted pair data lines, the switch operable to couple a selected subset of the twisted pair data lines to the second XDSL modems; and

a controller coupled to the switch and the twisted pair data lines, the controller operable to detect a need for data service from at least one computer over an associated twisted pair data line, the controller further operable to direct the switch to couple the associated twisted pair data line to a selected second XDSL modem in response to detecting the need.

7. The communication system of claim 1, wherein the communication server further comprises:

a switch coupled to the twisted pair data lines, the switch operable to couple a selected subset of the twisted pair data lines to the second XDSL modems; and

a controller coupled to the switch and the twisted pair data lines, the controller operable to poll in succession the twisted pair data lines to detect a need for data service from at least one computer over an associated twisted pair data line, the controller further operable to direct the switch to couple the associated twisted pair data line to a selected second XDSL modem in response to detecting the need.

8. The communication system of claim 1, wherein the number of second XDSL modems is less than the number of twisted pair subscriber lines.

9. The communication system of claim 1, wherein the splitter and the communication server are located at a central office.

10. A communication server coupled to a plurality of twisted pair data lines, each twisted pair data line coupled to an associated twisted pair subscriber line forming a local loop to a subscriber, the communication server comprising:

a plurality of XDSL modems;

a switch coupled to the plurality of XDSL modems, the switch to couple selected subsets of the twisted pair data lines to the XDSL modems;

a detector coupled to the switch and to detect a need for data service on a selected twisted pair data line; and

a processor coupled to the detector, the processor to select one of the plurality of XDSL modems in response to detecting the need, the processor further to direct the switch to couple the selected twisted pair data line to the selected XDSL modem, wherein the selected XDSL modem provides high bandwidth data service to the subscriber using the twisted pair subscriber line.

11. The communication server of claim 10, wherein the XDSL modems perform data modulation using asymmetric digital subscriber line technology.

12. The communication server of claim 10, wherein the XDSL modems are operable to receive information at a first rate and to transmit information at a second rate greater than the first rate.

13. The communication server of claim 10, wherein the switch comprises a cross-point matrix switch.

14. The communication server of claim 10, further comprising polling circuitry having a plurality of inputs coupled to the twisted pair data lines and a single output coupled to the detector, the polling circuitry to couple in succession the inputs to the output.

15. The communication server of claim 10, further comprising an activity table coupled to the processor, the activity table specifying a plurality of inactive twisted pair data lines, the processor operable to access the activity table and to direct the polling circuitry to poll the inactive twisted pair data lines specified in the activity table.

16. The communication server of claim 10, further comprising an activity table coupled to the processor, the activity table specifying a plurality of active twisted pair data lines, the processor operable to update the activity table to specify the selected twisted pair data line as one of the active twisted pair data lines.

17. The communication server of claim 10, further comprising an activity detector coupled to the XDSL modems, the activity detector operable to detect a predetermined period of inactivity of the XDSL modems.

18. The communication server of claim 10, further comprising a multiplexer coupled to the XDSL modems, the multiplexer operable to combine information received from the XDSL modems into a single multiplexed signal.

19. The communication server of claim 10, wherein the number of XDSL modems is less than the number of twisted pair subscriber lines.

20. The communication server of claim 10, wherein the communication server is located at a central office.

21. A method for coupling selected subsets of a plurality of twisted pair subscriber lines to a plurality of XDSL modems in order to off-load high bandwidth data service from a telephone switch, the method comprising:

splitting each twisted pair subscriber line into a twisted pair data line and a twisted pair phone line, each twisted pair subscriber line forming a local loop to a subscriber;

detecting a need for data service on a selected inactive twisted pair data line;

selecting one of the plurality of XDSL modems in response to detecting the need; and

coupling the selected inactive twisted pair data line to the selected XDSL modem, wherein the high bandwidth data service is provided to the subscriber using the selected XDSL modem rather than the telephone switch.

22. The method of claim 21, further comprising the step of coupling the twisted pair phone lines to the telephone switch to provide telephone service.

23. The method of claim 21, wherein the XDSL modems are located at a central office.

24. The method of claim 21, further comprising:

reading an activity table to identify an inactive twisted pair data line; and

coupling the detector to the identified inactive twisted pair data line.

25. The method of claim 21, further comprising:

reading an activity table to identify an inactive twisted pair data line;

coupling the detector to the identified inactive twisted pair data line; and

maintaining the coupling between the detector and the identified inactive twisted pair data line for a predetermined interval.

26. The method of claim 21, further comprising:

reading an activity table to identify an inactive twisted pair data line; and

providing a receiver with a profile of the identified inactive twisted pair data line.

27. The method of claim 21, further comprising:

reading an activity table to identify an inactive and non-dedicated twisted pair data line; and

coupling the detector to the identified inactive and nondedicated twisted pair data line.

28. The method of claim 21, further comprising:

reading an activity table to identify an inactive twisted pair data line associated with a valid and non-dedicated subscriber; and

coupling the detector to the identified inactive twisted pair data line.

29. The method of claim 21, further comprising the step of updating an activity table to indicate that the selected inactive twisted pair data line is active.

30. The method of claim 21, wherein the selected inactive twisted pair data line is redesignated an active twisted pair data line, further comprising the following steps to decouple the active twisted pair data line:

detecting a predetermined period of inactivity of the selected XDSL modem; and

decoupling the active twisted pair data line and the selected XDSL modem in response to detecting the predetermined period of inactivity.

31. The method of claim 21, wherein the selected inactive twisted pair data line is redesignated an active twisted pair data line, further comprising the following steps to decouple the active twisted pair data line:

detecting a predetermined period of inactivity of the selected XDSL modem;

decoupling the active twisted pair data line and the selected XDSL modem in response to detecting the predetermined period of inactivity; and

updating an activity table to indicate that the active twisted pair data line is inactive.

32. The method of claim 21, wherein the number of XDSL modems is less than the number of twisted pair subscriber lines.