Increasing capacity in a cable modem termination system (CMTS) with passive redundancy

• US 20040139473A1
• Filed: 01/10/2003
• Published: 07/15/2004
• Est. Priority Date: 01/10/2003
• Status: Abandoned Application

• Current Assignee: Bigband Networks Incorporated (II-VI Incorporated)
• Original Assignee: ADC Broadband Access Systems, Inc.
• Inventors: Greene, Clarke V.
• Application Number:
  US10/339,983
• Publication Number:
  US 20040139473A1
• Time in Patent Office: Days
• US Class Current: 725/111
• CPC Class Codes: H04B 1/74 for increasing reliability, e.g. using redundant or spare channels or apparatus replacing by standby devices for amplifiers H03F1/52, H03F1/542
• CPC Class Codes: H04L 1/22 using redundant apparatus to increase reliability
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 47/15 in relation to multipoint traffic arrangements for broadcast or multicast in data networks H04L12/18
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 47/745 Reaction in network
• CPC Class Codes: H04L 47/762 triggered by the network
• CPC Class Codes: H04L 47/788 Autonomous allocation of resources
• CPC Class Codes: H04N 21/2385 Channel allocation H04N21/266 takes precedence; Bandwidth allocation H04N21/24 takes precedence ; allocation of channels according to the instantaneous demands of the users in time-division multiplex systems H04J3/1682; admission control, resource allocation in open networks H04L12/5692; arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896; negotiating bandwidth in wireless networks H04W28/16
• CPC Class Codes: H04N 21/2402 Monitoring of the downstream path of the transmission network, e.g. bandwidth available traffic monitoring in data switching networks H04L43/00; monitoring data switching networks utilization H04L43/0876
• CPC Class Codes: H04N 21/2404 Monitoring of server processing errors or hardware failure error or fault detection G06F11/07; monitoring in general G06F11/30
• CPC Class Codes: H04N 21/6118 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 7/17309 Transmission or handling of upstream communications

Abstract

A method for adjusting bandwidth allocation in a cable modem termination system is provided. The method includes detecting an overflow condition at a primary transceiver of the cable modem termination system, determining whether a back-up transceiver is available in the cable modem termination system, and when the back-up transceiver is available, establishing at least one channel for the back-up transceiver to communicate over a common physical medium with at least one channel of the primary transceiver to effectively increase the bandwidth of the cable modem termination system.

Claims

1. A method for adjusting bandwidth allocation in a cable modem termination system, the method comprising:

detecting an overflow condition at a primary transceiver of the cable modem termination system;

determining whether a back-up transceiver is available in the cable modem termination system; and

when the back-up transceiver is available, establishing at least one channel for the back-up transceiver to communicate over a common physical medium with at least one channel of the primary transceiver to effectively increase the bandwidth of the cable modem termination system.

2. The method of claim 1, wherein detecting an overflow condition comprises detecting an intermittent need for additional bandwidth.

3. The method of claim 1, wherein detecting an overflow condition comprises monitoring flow rates at ports of the cable modem termination system.

4. The method of claim 3, wherein monitoring flow rates comprises monitoring flow rates to determine when a flow rate exceeds a selected flow rate.

5. The method of claim 1, and further identifying at least one channel serviced by the primary transceiver to move to the backup transceiver.

6. The method of claim 5, wherein identifying at least one channel comprises identifying at least one-third of the channels for moving to the backup transceiver.

7. A method for meeting intermittent increases in demand for bandwidth in a cable modem termination system having at least one primary transceiver and a back-up transceiver, the method comprising:

during a normal operation mode, communicating over at least one channel through a directional coupler and the at least one primary transceiver; and

during an overflow operation mode, communicating over at least one channel through a directional coupler and the at least one primary transceiver and over at least one additional channel through the directional coupler and the backup transceiver.

8. The method of claim 7, and further comprising returning to the normal mode when one of the at least one primary transceiver fails in overflow operation mode.

9. The method of claim 7, and further comprising communicating over at least one channel through a directional coupler and the backup transceiver when the at least one primary transceiver associated with the directional coupler fails.

10. The method of claim 7, and further comprising switching between normal and overflow operation modes when an overflow condition is detected.

11. The method of claim 7, and further comprising switching from overflow operation mode to normal operation mode when one of the at least one primary transceivers fails.

20. The method of claim 11, further comprising returning to the normal mode of operation upon detecting a failure of the at least one primary transceiver, comprising transferring the first and second portions of communication signals between the at least one port of the backup transceiver and the at least one directional coupler.

12. A method for increasing capacity of a cable modem termination system, the method comprising:

transferring communication signals between a directional coupler and a primary cable modem termination system transceiver during a normal operation mode; and

transferring communication signals between the directional coupler and the primary cable modem termination system transceiver and between the directional coupler and a backup cable modem termination system transceiver during an overflow operation mode.

13. The method of claim 12, further comprising entering the overflow operation mode when an overflow condition is detected.

14. A method of operating a cable modem termination system, the method comprising:

transferring communication signals between at least one port of at least one primary cable modem termination system transceiver and at least one port of a directional coupler during a normal operation mode, wherein the at least one directional coupler is connected between the at least one port and a head end or subscriber equipment;

detecting a data overflow condition between the at least one directional coupler and the head end or subscriber equipment; and

entering an overflow mode of operation comprising transferring a first portion of communication signals between the at least one port of the primary cable modem termination system transceiver and the at least one directional coupler and transferring a second portion of communication signals between at least one port of a backup cable modem termination system transceiver and the at least one directional coupler.

15. The method of claim 14, further comprising amplifying the second portion of the communication signals.

16. The method of claim 14, further comprising amplifying the second portion of the communication signals to compensate for losses through the directional coupler to create communication signals with near unity gain.

17. The method of claim 16, further comprising:

detecting a level of the second portion of communication signals; and

adjusting the amplification based on the detected level to create the communication signals with near unity gain.

18. The method of claim 14, further comprising monitoring the transfer of the communication signals between the at least one directional coupler and the head end or subscriber equipment.

19. The method of claim 14, further comprising returning to the normal operation mode upon detecting that the overflow condition no longer occurs.

21. A machine-readable medium comprising machine-readable instructions for causing a cable modem termination system to perform a method of increasing capacity of the cable modem termination system, the method comprising:

transferring communication signals between a directional coupler and a primary cable modem termination system transceiver during a normal operation mode; and

transferring communication signals between the directional coupler and the primary cable modem termination system transceiver and between the directional coupler and a backup cable modem termination system transceiver during an overflow operation mode.

22. The machine readable medium of claim 21, further comprising entering the overflow operation mode when an overflow condition is detected.

23. A machine-readable medium comprising machine-readable instructions for causing a cable modem termination system to perform a method for adjusting bandwidth allocation in a cable modem termination system, the method comprising:

detecting an overflow condition at a primary transceiver of the cable modem termination system;

determining whether a back-up transceiver is available in the cable modem termination system; and

when the back-up transceiver is available, establishing at least one channel for the back-up transceiver to communicate over a common physical medium with at least one channel of the primary transceiver to effectively increase the bandwidth of the cable modem termination system.

24. The machine-readable medium of claim 23, wherein detecting an overflow condition comprises detecting an intermittent need for additional bandwidth.

25. The machine-readable medium of claim 23, wherein detecting an overflow condition comprises monitoring flow rates at ports of the cable modem termination system.

26. The machine-readable medium of claim 25, wherein monitoring flow rates comprises monitoring flow rates to determine when a flow rate exceeds a selected flow rate.

27. The machine-readable medium of claim 23, and further identifying at least one channel serviced by the primary transceiver to move to the backup transceiver.

28. The machine-readable medium of claim 27, wherein identifying at least one channel comprises identifying at least one-third of the channels for moving to the backup transceiver.

29. A machine-readable medium comprising machine-readable instructions for causing a cable modem termination system to perform a method of operating the cable modem termination system, the method comprising:

transferring communication signals between at least one port of at least one primary cable modem termination system transceiver and at least one port of a directional coupler during a normal operation mode, wherein the at least one directional coupler is connected between the at least one port and a head end or subscriber equipment;

detecting a data overflow condition between the at least one directional coupler and the head end or subscriber equipment; and

entering an overflow mode of operation comprising transferring a first portion of communication signals between the at least one port of the primary cable modem termination system transceiver and the at least one directional coupler and transferring a second portion of communication signals between at least one port of a backup cable modem termination system transceiver and the at least one directional coupler.

30. The method of claim 29, further comprising monitoring the data transfer of the communication signals between the at least one directional coupler and the head end or subscriber equipment.

31. The method of claim 29, further comprising returning to the normal operation mode upon detecting that the overflow condition no longer occurs.

32. The method of claim 29, further comprising returning to the normal mode of operation upon detecting a failure of the at least one primary transceiver, the normal mode of operation comprising transferring the first and second portions of the communication signals between the at least one port of the backup cable modem termination system transceiver and the at least one directional coupler.

33. A cable modem termination system, comprising:

at least one primary cable modem termination system transceiver;

at least one directional coupler connected to the primary cable modem termination system transceiver through a primary signal path;

one backup cable modem termination system transceiver selectively connected to the at least one directional coupler through a secondary signal path outside of the primary signal path; and

a machine-readable medium comprising machine-readable instructions for causing the at least one primary cable modem termination system transceiver to transceive communication signals through the primary signal path during a normal operating mode and for causing the at least one primary cable modem termination system transceiver to transceive a first portion of communication signals through the primary signal path and the one backup cable modem termination system transceiver to transceive a second portion of communication signals through the secondary signal path during an overflow operating mode.

34. The cable modem termination system of claim 33, further comprising at least one switch module connected between the backup cable modem termination system transceiver and the at least one primary cable modem termination system transceiver for selectively connecting the backup cable modem termination system transceiver to the at least one directional coupler.

35. The cable modem termination system of claim 34, wherein the at least one switch module further comprises an amplifier connected between the one backup cable modem termination system transceiver and the at least one primary cable modem termination system transceiver.

36. The cable modem termination system of claim 34, wherein the at least one switch module further comprises RF level correction circuitry.

37. A cable modem termination system comprising:

at least two primary cable modem termination system transceivers;

a plurality of directional couplers connected to each of the at least two primary cable modem termination system transceivers through a primary signal path;

one backup CMTS transceiver selectively connected to the plurality of directional couplers through a secondary signal path outside of the primary signal path; and

a machine-readable medium comprising machine-readable instructions for causing the at least two primary cable modem termination system transceivers to transceive communication signals through the primary signal path during a normal operating mode and for causing one or both of the at least two primary cable modem termination system transceivers to transceive a first portion of communication signals through the primary signal path and the one backup cable modem termination system transceiver to transceive a second portion of communication signals through the secondary signal path during an overflow operating mode.

38. The cable modem termination system of claim 37, further comprising a switch module connected between the backup cable modem termination system transceiver and the at least two primary cable modem termination system transceivers for selectively connecting the backup cable modem termination system transceiver to the plurality of directional couplers.

39. The cable modem termination system of claim 38, wherein the backup and the at least two primary cable modem termination system transceivers each further comprise one or more upstream communication ports and one or more downstream communication ports, wherein each communication port of each of the at least two primary cable modem termination system transceivers is connected to one of the plurality of directional couplers, wherein the switch module further comprises an upstream switch module associated with each upstream communication port of the backup cable modem termination system transceiver for selectively connecting that upstream communication port to a directional coupler associated with a corresponding upstream communication port of one of the at least two primary cable modem termination system transceivers, and wherein the switch module further comprises a downstream switch module associated with each downstream communication port of the backup cable modem termination system transceiver for selectively connecting that downstream communication port to a directional coupler associated with a corresponding downstream communication port of one of the at least two primary cable modem termination system transceivers.

40. The cable modem termination system of claim 39, wherein each switch module further comprises an amplifier connected between its associated communication port of the backup cable modem termination system transceiver and the associated communication ports of the at least two primary cable modem termination system transceivers.

41. The cable modem termination system of claim 38, wherein each switch module further comprises RF level correction circuitry.

42. An overflow system for a cable modem termination system, comprising:

a first directional coupler comprising a first port for connecting to a communication line, a second port connected to a primary cable modem termination system transceiver, and a third port selectively connected to a backup cable modem termination system transceiver; and

a machine-readable medium comprising machine-readable instructions for causing the primary cable modem termination system transceiver to transceive communications on the communication line in a normal operation mode and the primary cable modem termination system transceiver to transceive a first portion of communications on the communication line and the backup cable modem termination system transceiver to transceive a second portion of communications on the communication line in an overflow operation mode.

43. The overflow system of claim 42, further comprising a switch module connected between the backup cable modem termination system transceiver and the first directional coupler for selectively connecting the backup cable modem termination system transceiver to the third port of the first directional coupler or to a third port of another first directional coupler connected to another primary cable modem termination system transceiver.

44. A cable modem termination system, comprising:

at least one primary cable modem termination system transceiver comprising one or more upstream communication ports for communication with subscriber equipment and one or more downstream communication ports for communication with a head end;

at least one backup cable modem termination system transceiver comprising one or more upstream communication ports for communication with the subscriber equipment and one or more downstream communication ports for communication with the head end; and

a plurality of directional couplers, with a directional coupler connected to each communication port of the at least one primary cable modem termination system transceiver through a first signal path;

wherein each communication port of the at least one backup cable modem termination system transceiver is selectively connected to a directional coupler of a corresponding communication port of the at least one primary cable modem termination system transceiver through a second signal path; and

a machine-readable medium comprising machine-readable instructions for causing the at least one primary cable modem termination system transceiver to transceive communication signals through the primary signal path during a normal operating mode and for causing the at least one primary cable modem termination system transceiver to transceive a first portion of communication signals through the first signal path and the one backup cable modem termination system transceiver to transceive a second portion of communication signals through the second signal path during an overflow operating mode.

45. The cable modem termination system of claim 81, further comprising a switch module connected between the at least one backup cable modem termination system transceiver and the at least one primary cable modem termination system transceivers for selectively connecting the at least one backup cable modem termination system transceiver to the plurality of directional couplers.