System and method to provide survivability for broadcast video and interactive IP-based services on cable access networks

• US 6,535,480 B1
• Filed: 11/20/1998
• Issued: 03/18/2003
• Est. Priority Date: 11/20/1998
• Status: Expired due to Fees

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Bhagavath, Vijay K., OʼNeil, Joseph Thomas
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US09/197,170
• Time in Patent Office: 1,579 Days
• Field of Search: 370/216-228, 370/209, 370/242, 370/245, 370/252, 370/253, 370/463, 370/490, 370/485-489, 455/423, 455/426, 455/428, 455/429
• US Class Current: 370/225
• CPC Class Codes: H04N 21/6338 directed to network
• CPC Class Codes: H04N 21/643 Communication protocols network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP], H04L65/65
• CPC Class Codes: H04N 21/64723 Monitoring of network processes or resources, e.g. monitoring of network load traffic related reporting in data switching networks H04L43/062
• CPC Class Codes: H04Q 11/0067 Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring
• CPC Class Codes: H04Q 2011/0081 Fault tolerance; Redundancy; Recovery; Reconfigurability

Abstract

A hybrid fiber/coaxial cable is attached to an autonomous controller which includes a wireless receiver, transmitter, and antenna. Typically, the autonomous controller is connected near the end of the cable which is remote from the headend. At least one other hybrid fiber/coaxial cable connected to the same headend or distribution hub, provides connectivity for cable data modems and set top boxes in an adjacent neighborhood or community. The second cable is attached to its own, respective autonomous controller which also has a wireless receiver, transmitter, and antenna. The two antennas in the adjacent neighborhoods constitute an antenna cluster. When the first cable'"'"'s connection to the common headend is interrupted, thereby preventing service to the first neighborhood, its autonomous controller senses the interruption and responds by sending a wireless signal to the controller in the adjacent neighborhood. In response, the two controllers use an antenna cluster protocol (ACP) to set up a wireless communications path through the second cable to the headend. In this manner, service is restored from the headend to the cable data modems and set top boxes in the first neighborhood.

Claims

1. A system to provide survivability in a communications network, comprising:

a plurality of autonomous controllers selectively communicating with each other over a wireless medium, each having a wireless antenna, each having a respective state machine, each coupled to respective traffic nodes, and coupled to a respective network link which is coupled to a common distribution hub;

said state machines each having a standby state, a protected state, and an active state;

said state machines each respectively assuming said standby state for its controller to prohibit communication over a wireless medium when receiving a signal from said hub via its said respective link;

one of said state machines respectively assuming said protected state for its controller when it does not receive a signal from said hub via its said respective link, and in response thereto enabling signals to and from a respective one of said traffic nodes coupled thereto to pass via its wireless antenna to and from said hub through the wireless antenna of another one of said autonomous controllers which is in said active state; and

said another one of said state machines assuming said active state for its controller when it receives a protected state signal via its wireless antenna from the wireless antenna of said one of said autonomous controllers in said protected state, and in response thereto enabling traffic signals to and from said protected state controller to pass via the wireless antenna of said active state controller to and from said hub.

2. The system to provide survivability in a communications network of claim 1, further comprising:

said active state controller changing from said standby state to said active state in response to receiving said protected state signal via its wireless antenna, and broadcasting an active state signal via its wireless antenna, which is monitored by said controllers in said standby state and in said protected state.

3. The system to provide survivability in a communications network of claim 1, further comprising:

said protected state controller setting a receiver coupled to its wireless antenna at a downstream frequency and setting a transmitter coupled to its wireless antenna at an upstream frequency; and

said active state controller setting a receiver coupled to its wireless antenna at said upstream frequency and setting a transmitter coupled to its wireless antenna at said downstream frequency.

4. The system to provide survivability in a communications network of claim 1, further comprising:

each of said plurality of controllers having a unique identity and priority for remaining in said active state, to prevent more than one of said controllers from remaining in said active state at the same time.

5. The system to provide survivability in a communications network of claim 1, further comprising:

each of said plurality of controllers having a unique waiting period for assuming said active state from said standby state, to prevent more than one of said controllers from assuming said active state at the same time.

6. The system to provide survivability in a communications network of claim 1, further comprising:

said protected state controller reverting to said standby state when it resumes receiving a signal from said hub via its said respective link.

7. The system to provide survivability in a communications network of claim 1, further comprising:

said active state controller reverting to said standby state when it no longer receives said protected state signals via its wireless antenna.

8. The system to provide survivability in a communications network of claim 1, further comprising:

said active state controller enabling traffic signals to and from a plurality of said protected state controllers to pass via the wireless antenna of said active state controller to and from said hub.

9. The system to provide survivability in a communications network of claim 2, further comprising:

said protected state signal being an ICMP message broadcast via the wireless antenna of said controller in said protected state; and

said active state signal being an ICMP message broadcast via the wireless antenna of said controller in said active state.

10. The system to provide survivability in a communications network of claim 1, further comprising:

said signals from said traffic nodes being encrypted before being transmitted by said wireless antenna of said protected state controller; and

said signals from said hub being encrypted before being transmitted by said wireless antenna of said active state controller.

11. The system to provide survivability in a communications network of claim 1, further comprising:

each of said controllers in said standby state having a wireless receiver operating to receive signals from its wireless antenna and having a wireless transmitter that is turned off to conserve power;

said protected state controllers and said active state controllers each having their respective said wireless transmitter turned on.

12. The system to provide survivability in a communications network of claim 2, further comprising:

said protected state signal and said active state signal are not sent to said distribution hub.

13. The system to provide survivability in a communications network of claim 2, further comprising:

said protected state signal is broadcast by said protected state controller at periodic intervals and said active state signal is broadcast by said active state controller at periodic intervals.

14. The system to provide survivability in a communications network of claim 13, further comprising:

each of said plurality of controllers having a second waiting period which is greater than said periodic repetition interval, for reverting from said active state to said standby state after said protected state signals are no longer received via its wireless antenna.

15. The system to provide survivability in a communications network of claim 1, further comprising:

a protected state ICMP alarm message is sent to said distribution hub to provide notice that the respective link of said protected state controller has failed.

16. The system to provide survivability in a communications network of claim 1, further comprising:

a protected state SNMP trap PDU alert message is sent to said distribution hub to provide notice that the respective link of said protected state controller has failed.

17. The system to provide survivability in a communications network of claim 1, further comprising:

said respective links being hybrid fiber/coaxial cable and said traffic nodes being cable data modems.

18. The system to provide survivability in a communications network of claim 1, further comprising:

said distribution hub being coupled to an Internet protocol network and said traffic signals being Internet protocol network signals.

19. The system to provide survivability in a communications network of claim 1, further comprising:

said distribution hub being coupled to a telephone network and said traffic signals being telephone signals.

20. The system to provide survivability in a communications network of claim 1, further comprising:

said distribution hub being coupled to a source of video and audio channels; and

said respective links being coupled to set top boxes for receiving said video and audio channels.

21. A communications network topology, comprising:

a first autonomous controller selectively communicating over a wireless medium, having a wireless antenna and having a first state machine, coupled to a first network link which is coupled to a distribution hub, said first link including a first traffic node;

a second autonomous controller selectively communicating over a wireless medium, having a wireless antenna and having a second state machine, coupled to a second network link which is coupled to said distribution hub, said second link including a second traffic node;

said state machines each having a standby state, a protected state, and an active state;

said state machines each respectively assuming said standby state for its controller to prohibit communication over a wireless medium when receiving a signal from said hub via its said respective link;

said first state machine assuming said protected state for said first controller when it does not receive a signal from said hub via said first link, and in response thereto enabling signals to and from said first traffic node to pass via its wireless antenna to and from said hub through the wireless antenna of said second controller which is in said active state; and

said second state machine assuming said active state for said second controller when it receives a protected state signal via its wireless antenna from the wireless antenna of said first controller in said protected state, and in response thereto enabling traffic signals to and from said first controller to pass via the wireless antenna of said second controller to and from said hub.

22. The communications network topology of claim 21, further comprising:

said second controller changing from said standby state to said active state in response to receiving said protected state signal via its wireless antenna, and broadcasting an active state signal via its wireless antenna, which is monitored by said first controller in said protected state.

23. The communications network topology of claim 21, further comprising:

said first controller setting a receiver coupled to its wireless antenna at a downstream frequency and setting a transmitter coupled to its wireless antenna at an upstream frequency; and

said second controller setting a receiver coupled to its wireless antenna at said upstream frequency and setting a transmitter coupled to its wireless antenna at said downstream frequency.

24. The communications network topology of claim 21, further comprising:

each of said controllers having a unique identity and priority for remaining in said active state, to prevent more than one of said controllers from remaining in said active state at the same time.

25. The communications network topology of claim 21, further comprising:

each of said plurality of controllers having a unique waiting period for assuming said active state from said standby state, to prevent more than one of said controllers from assuming said active state at the same time.

26. The communications network topology of claim 21, further comprising:

said first controller reverting to said standby state when it resumes receiving a signal from said hub via said first link.

27. The communications network topology of claim 21, further comprising:

said second controller reverting to said standby state when it no longer receives said protected state signals via its wireless antenna.

28. The communications network topology of claim 21, further comprising:

said second controller enabling traffic signals to and from a plurality of said first controllers in said protected state to pass via the wireless antenna of said second controller to and from said hub.

29. The communications network topology of claim 22, further comprising:

said protected state signal being an ICMP message broadcast via the wireless antenna of said first controller in said protected state; and

said active state signal being an ICMP message broadcast via the wireless antenna of said second controller in said active state.

30. The communications network topology of claim 21, further comprising:

said signals from said first traffic node being encrypted before being transmitted by said wireless antenna of first controller; and

said signals from said hub being encrypted before being transmitted by said wireless antenna of second controller.

31. The communications network topology of claim 21, further comprising:

each of said controllers in said standby state having a wireless receiver operating to receive signals from its wireless antenna and having a wireless transmitter that is turned off to conserve power; and

said first controllers and said second controllers each having their respective said wireless transmitter turned on.

32. The communications network topology of claim 22, further comprising:

said protected state signal and said active state signal are not sent to said distribution hub.

33. The communications network topology of claim 22, further comprising:

said protected state signal is broadcast by said first controller at periodic intervals and said active state signal is broadcast by said second controller at periodic intervals.

34. The communications network topology of claim 33, further comprising:

each of said plurality of controllers having a second waiting period which is greater than said periodic repetition interval, for reverting from said active state to said standby state after said protected state signals are no longer received via its wireless antenna.

35. The communications network topology of claim 21, further comprising:

a protected state ICMP alarm message is sent to said distribution hub to provide notice that said first link of said first controller has failed.

36. The communications network topology of claim 21, further comprising:

a protected state SNMP trap PDU alert message is sent to said distribution hub to provide notice that said first link of said first controller has failed.

37. The communications network topology of claim 21, further comprising:

said first and second links being hybrid fiber/coaxial cable and said first traffic node being a cable data modem.

38. The communications network topology of claim 21, further comprising:

said distribution hub being coupled to an Internet protocol network and said traffic signals being Internet protocol network signals.

39. The communications network topology of claim 21, further comprising:

said distribution hub being coupled to a telephone network and said traffic signals being telephone signals.

40. The communications network topology of claim 21, further comprising:

said distribution hub being coupled to a source of video and audio channels; and

said first and second links being coupled to set top boxes for receiving said video and audio channels.

41. A communications network method, comprising:

providing a first autonomous controller selectively communicating over a wireless medium, having a wireless antenna and having a first state machine, coupled to a first network link which is coupled to a distribution hub, said first link including a first traffic node;

providing a second autonomous controller selectively communicating over a wireless medium, having a wireless antenna and having a second state machine, coupled to a second link which is coupled to said distribution hub, said second network link including a second traffic node;

said state machines each having a standby state, a protected state, and an active state;

setting each of said state machines in said standby state for its controller to prohibit communication over a wireless medium when receiving a signal from said hub via its said respective link;

setting said first state machine in said protected state for said first controller when it does not receive a signal from said hub via said first link, and in response thereto enabling signals to and from said first traffic node to pass via its wireless antenna to and from said hub through the wireless antenna of said second controller which is in said active state; and

setting said second state machine in said active state for said second controller when it receives a protected state signal via its wireless antenna from the wireless antenna of said first controller in said protected state, and in response thereto enabling traffic signals to and from said first controller to pass via the wireless antenna of said second controller to and from said hub.

42. The communications network method of claim 41, further comprising:

changing said second controller from said standby state to said active state in response to receiving said protected state signal via its wireless antenna, and broadcasting an active state signal via its wireless antenna, which is monitored by said first controller in said protected state.

43. A communications controller, comprising:

a wireless receiver and wireless transmitter coupled to a wireless antenna;

a state machine coupled to said wireless receiver and said wireless transmitter, and coupled to a first network link which is coupled to a distribution hub, said first link including a first traffic node;

said state machine having a standby state, a protected state, and an active state;

said state machine assuming said standby state for the controller to prohibit communication over a wireless medium when receiving a signal from said hub via its said respective link;

said state machine assuming said protected state for the controller when it does not receive a signal from said hub via said first link, and in response thereto enabling signals to and from said first traffic node to pass via its wireless antenna to and from said hub through the wireless antenna of another controller substantially the same as said controller, said other controller being in said active state; and

said state machine assuming said active state for the controller when it receives a protected state signal via its wireless antenna from the wireless antenna of said another controller when in said protected state, and in response thereto enabling traffic signals to and from said another controller in said protected state to pass via the wireless antenna to and from said hub.

44. The communications controller claim 43, further comprising:

said controller changing from said standby state to said active state in response to receiving said protected state signal via its wireless antenna, and broadcasting an active state signal via its wireless antenna, which is monitored by said another controller in said protected state.

45. The communications controller claim 43, further comprising:

said controller when in said protected state setting said receiver at a downstream frequency and setting said transmitter at an upstream frequency; and

said controller when in said active state setting said receiver at said upstream frequency and setting said transmitter at said downstream frequency.

46. The communications controller of claim 43, further comprising:

said controller having a unique identity and priority for remaining in said active state, to prevent a plurality of said controllers from remaining in said active state at the same time.

47. The communications controller of claim 43, further comprising:

said controller having a unique waiting period for assuming said active state from said standby state, to prevent a plurality of said controllers from assuming said active state at the same time.

48. The communications controller of claim 43, further comprising:

said controller reverting from said protected state to said standby state when it resumes receiving a signal from said hub via said first link.

49. The communications controller of claim 43, further comprising:

said controller reverting from said active state to said standby state when it no longer receives said protected state signals via its wireless antenna.

50. The communications controller of claim 43, further comprising:

said controller when in said active state, enabling traffic signals to and from a plurality of said controllers in said protected state to pass to and from said hub via said wireless antenna.

51. The communications controller of claim 44, further comprising:

said protected state signal being an ICMP message broadcast via the wireless antenna of said controller when in said protected state; and

said active state signal being an ICMP message broadcast via the wireless antenna of said controller when in said active state.

52. The communications controller of claim 43, further comprising:

said signals from said first traffic node being encrypted before being transmitted by said wireless antenna of controller.

53. The communications controller of claim 43, further comprising:

said controller in said standby state controlling said wireless receiver to receive signals from its wireless antenna and controlling said wireless transmitter to be turned off to conserve power; and

said controller in said protected state and in said active state having said wireless transmitter turned on.

54. The communications controller of claim 44, further comprising:

said protected state signal and said active state signal not being sent to said distribution hub.

55. The communications controller of claim 44, further comprising:

said protected state signal being broadcast by said controller at periodic intervals and said active state signal being broadcast by said controller at periodic intervals.

56. The communications controller of claim 55, further comprising:

said controller having a second waiting period which is greater than said periodic repetition interval, for reverting from said active state to said standby state after said protected state signals are no longer received via its wireless antenna.

57. The communications controller of claim 44, further comprising:

a protected state ICMP alarm message being sent to said distribution hub to provide notice that said first link has failed.

58. The communications controller of claim 44, further comprising:

a protected state SNMP trap PDU alert message being sent to said distribution hub to provide notice that said first link has failed.

59. The communications controller of claim 44, further comprising:

said first link being hybrid fiber/coaxial cable and said first traffic node being a cable data modem.

60. The communications controller of claim 44, further comprising:

said distribution hub being coupled to an Internet protocol network and said traffic signals being Internet protocol network signals.

61. The communications controller of claim 44, further comprising:

said distribution hub being coupled to a telephone network and said traffic signals being telephone signals.

62. The communications controller of claim 44, further comprising:

said distribution hub being coupled to a source of video and audio channels; and

said first link being coupled to set top boxes for receiving said video and audio channels.

63. The communications controller of claim 43, further comprising:

a routing table in said distribution hub to route said signals to and from said first traffic node via said first link when said controller is in said standby state;

said controller sending an alarm message to said routing table in said distribution hub to provide notice that a second link coupled to a protected state controller has failed;

said routing table responding to said alarm message by rerouting signals to and from a second traffic node included in said second link, to pass via said first link and said wireless antenna to and from said second link.

64. The communications controller of claim 43, further comprising:

a routing table in said distribution hub to route said signals to and from said first traffic node via said first link when said when said controller is in said standby state;

said controller sending an SNMP trap PDU alert to said routing table in said distribution hub to provide notice that a second link coupled to a protected state controller has failed;

said routing table responding to said alert by rerouting signals to and from a second traffic node included in said second link to pass via said first link and said wireless antenna to and from said second link.

65. A communications control method, comprising:

establishing a standby state for a communications controller to prohibit communication over a wireless medium while hub signals are being received over a communications link from a distribution hub;

changing said controller from said standby state to a protected state if said hub signals are not received, and in response thereto transmitting a protected state signal via a wireless antenna to another controller;

receiving an active state signal from said another controller via said wireless antenna, and in response thereto, said controller in said protected state enabling traffic signals to and from a traffic node on said communications link to pass via said wireless antenna to said another controller which is in an active state;

said another controller being connected over a second communications link to said distribution hub as an alternate path for said traffic signals to pass to and from said hub.

66. The communications control method of claim 65, further comprising:

changing said controller from said protected state to said standby state if said controller resumes receiving said hub signals;

changing said controller from said standby state to said active if said protected state signals are received via said wireless antenna from said another controller, and in response thereto transmitting said active state signal via said wireless antenna to said another controller; and

exchanging second traffic signals to and from said another controller which is in said protected state to via said wireless antenna and passing said second traffic signals to and from said hub via said communications link.

67. A communications control method, comprising:

establishing a standby state for a communications controller to prohibit communication over a wireless medium while hub signals are being received over a network communications link from a router at a distribution hub;

changing said controller from said standby state to a protected state if signals are not received from said hub, and in response thereto transmitting a protected state signal via a wireless antenna to another controller;

sending an alarm message to said router from said another controller which is in an active state, giving notice that said controller in said protected state must have traffic signals to and from a traffic node on said communications link rerouted over a second communications link between said distribution hub and said another controller;

receiving an active state signal from said another controller via said wireless antenna, and in response thereto, said controller in said protected state enabling traffic signals to and from said traffic node to pass via said wireless antenna to said another controller in said active state.

68. The communications control method of claim 67, further comprising:

changing said controller from said protected state to said standby state if said controller resumes receiving said hub signals;

changing said controller from said standby state to said active state if said protected state signals are received via said wireless antenna from said another controller, and in response thereto transmitting said active state signal via said wireless antenna to said another controller;

sending a second alarm message to said router from said controller which is in an active state, giving notice that said another controller in said protected state must have traffic signals to and from a second traffic node on said second communications link rerouted over said communications link between said distribution hub and said controller; and

exchanging second traffic signals to and from said another controller which is in said protected state to via said wireless antenna and passing said second traffic signals to and from said hub via said communications link.

69. A communications network, comprising:

a first communications controller establishing a standby state to prohibit communication over a wireless medium while hub signals are being received over a first network communications link from a router at a distribution hub;

said first communications controller changing from said standby state to a protected state if signals are not received from said hub, and in response thereto transmitting a protected state wireless signal via a wireless antenna;

a second communications controller receiving said protected state wireless signal and in response thereto, changing from a standby state to an active state;

said second communications controller sending a control message to said router over a second network communications link between said distribution hub and said second controller, giving notice that said first controller in said protected state must have traffic signals to and from a traffic node on said first communications link rerouted over said second communications link; and

said first communications controller receiving a wireless active state signal from said second controller via said wireless antenna, and in response thereto, said first controller in said protected state enabling traffic signals to and from said traffic node to pass via said wireless antenna, through said second controller and through said second communications link.

70. The communications network of claim 69, further comprising:

said second controller sending an SNMP trap PDU alert to said router in said distribution hub giving notice that said first communications link has failed.

71. The communications network of claim 69, further comprising:

said second controller sending an ICMP alarm message to said router in said distribution hub giving notice that said first communications link has failed.

72. A system to provide survivability in a communications network, comprising:

a plurality of controllers, each having a respective state machine, each coupled to respective traffic nodes, and coupled to a respective network link which is coupled to a common distribution hub;

said state machines each having a standby state, a protected state, and an active state;

said state machines each respectively assuming said standby state for its controller when receiving a signal from said hub via its said respective network link;

one of said state machines respectively assuming said protected state for its controller when it does not receive a signal from said hub via its said respective network link, and in response thereto enabling signals to and from a respective one of said traffic nodes coupled thereto to pass via its wireless antenna to and from said hub through another one of said controllers which is in said active state; and

another one of said state machines assuming said active state for its controller when it receives a protected state signal via its wireless antenna from said one of said controllers in said protected state, and in response thereto enabling traffic signals to and from said protected state controller to pass via the wireless antenna of said active state controller to and from said hub.

73. A system to provide survivability in a communications network, comprising:

a plurality of controllers, each connected over a respective network link to a common distribution hub;

a state machine in each of said controllers, having a standby state, a protected state, and an active state;

said standby state existing when a first controller of the plurality is receiving a signal over its respective network link from the hub;

said first controller transitioning to the protected state when the first controller does not receive a signal over its respective network link from the hub, said first controller in the protected state sending a wireless request for connection to a second controller of the plurality, the second controller transitioning to the active state to provide over the wireless connection to the first controller, the missing signals from the hub;

said the first controller alternately transitioning from the standby state to the active state when it receives a request from another controller of the plurality to pass signals the first controller has received from the hub over its respective network link, passing those signals via a wireless connection to the other controller making the request.