Optical communications system with dynamic channel allocation

• US 6,583,901 B1
• Filed: 02/23/2000
• Issued: 06/24/2003
• Est. Priority Date: 02/23/2000
• Status: Expired due to Fees

• Current Assignee: Micro Photonic Integration Corporation
• Original Assignee: Micro Photonic Integration Corporation
• Inventors: Hung, Henry
• Primary Examiner(s): Pascal, Leslie
• Assistant Examiner(s): SEDIGHIAN, REZA
• Application Number:
  US09/511,053
• Time in Patent Office: 1,217 Days
• Field of Search: 359/124, 359/125, 359/118, 359/119, 359/120, 359/121, 359/137, 359/127, 372/21, 372/22, 372/29.023
• US Class Current: 398/79
• CPC Class Codes: G02B 6/2821 using lateral coupling between contiguous fibres to split or combine optical signals
• CPC Class Codes: H01S 3/0675 Resonators including a grating structure, e.g. distributed Bragg reflectors [DBR] or distributed feedback [DFB] fibre lasers
• CPC Class Codes: H01S 3/2383 Parallel arrangements
• CPC Class Codes: H04J 14/002 Coherencemultiplexing
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems
• CPC Class Codes: H04J 14/0204 Broadcast and select arrangements, e.g. with an optical splitter at the input before adding or dropping
• CPC Class Codes: H04J 14/0205 Select and combine arrangements, e.g. with an optical combiner at the output after adding or dropping
• CPC Class Codes: H04J 14/0227 Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
• CPC Class Codes: H04J 14/0246 using one wavelength per ONU
• CPC Class Codes: H04J 14/0282 WDM tree architectures
• CPC Class Codes: H04J 14/0283 WDM ring architectures
• CPC Class Codes: H04J 14/0284 WDM mesh architectures

Abstract

Optical communication system apparatus and methods of operating an optical communications system is described. The system advantageously may utilize existing optical fiber networks and provide significantly increased channel capacity. In accordance with one aspect of the invention the system apparatus provides for a plurality of communications channels and a processor unit receives requests for allocation of one or more channels from a node coupled to the optical communications system. The system apparatus dynamically allocates one or more channels selected from unused channels.

Claims

1. A method of operating an optical network coupling a plurality of nodes, comprising:

providing a plurality of optical channels, each channel being determined by three variables, a first one of said variables being selected from a plurality of wavelengths, a second one of said variables being selected from a plurality of phases, and a third one of said variables being selected from a plurality of modulation frequencies;

providing first status indications for unused channels of said plurality of optical channels; and

dynamically allocating unused ones of said plurality of channels in response to requests for channels from said nodes.

2. A method in accordance with claim 1, comprising:

receiving a request from a first node of said plurality of nodes for allocation of one of said plurality of channels; and

dynamically allocating one channel of said unused channels as a communications channel between said first node and at least a second node of said plurality of nodes.

3. A method in accordance with claim 2, comprising:

changing said first status indication for said one channel when said one channel is allocated as a communications channel.

4. A method in accordance with claim 3, comprising:

determining when communication between said first node and said second node on said dynamically allocated one channel is complete; and

providing said first status indication for said one channel when said communication is determined to be complete.

5. A method in accordance with claim 1, comprising:

dynamically allocating one channel from said unused ones of said plurality of channels in accordance with a predetermined algorithm.

6. A method in accordance with claim 1, comprising:

dynamically allocating one channel from said unused ones of said plurality of channels to minimize cross channel interference with used ones of said channels.

7. A method in accordance with claim 1, comprising:

dynamically allocating one channel from said unused ones of said plurality of channels to maximize the distance between said one channel and used ones of said channels.

8. A method in accordance with claim 2, comprising:

selecting said one channel in accordance with a predetermined algorithm.

9. A method in accordance with claim 2, comprising:

selecting said one channel to minimize cross channel interference between said one channel and used ones of said channels.

10. A method in accordance with claim 2, comprising:

selecting said one channel to maximize the distance between said one channel and used ones of said channels.

11. A method in accordance with claim 3, comprising:

selecting said one channel in accordance with a predetermined algorithm.

12. A method in accordance with claim 3, comprising:

selecting said one channel to minimize interference between said one channel and used ones of said channels.

13. A method in accordance with claim 3, comprising:

selecting said one channel to maximize the distance between said one channel and used ones of said channels.

14. A method in accordance with claim 4, comprising:

selecting said one channel for allocation in accordance with a predetermined algorithm.

15. A method in accordance with claim 4, comprising:

selecting said one channel to minimize interference between said one channel and used ones of said channels.

16. A method in accordance with claim 4, comprising:

selecting one channel in accordance with a predetermined algorithm.

17. A method of operating a fiber optic network coupling a plurality of nodes comprising;

providing a plurality of optical channels, each channel being determined by three variables, a first one of said variables being selected from a plurality of wavelengths, a second one of said variables being selected from a plurality of phases, a third one of said variables being selected from a plurality of modulation frequencies;

providing status indications for unused channels of said plurality of optical channels;

dynamically allocating unused channels of said plurality of optical channels in response to requests for channels from said nodes; and

performing said dynamic allocation in accordance with a predetermined channel selection algorithm for selecting channels based upon a distance to used channels.

18. A method in accordance with claim 17, comprising:

receiving a request from a first node of said plurality of nodes for one of said plurality of channels; and

dynamically allocating one channel of said unused ones of said plurality of channels as a communications channel between said first node and at least a second node of said plurality of nodes in accordance with said algorithm.

19. A method in accordance with claim 18, comprising:

changing said status indication for said one channel during said allocating step.

20. A method in accordance with claim 19, comprising:

terminating communication between said first and second nodes; and

changing said status indication of said one channel to unused.

21. A method in accordance with claim 17, comprising:

selecting said unused channels to maximize the distance between a selected one channel and used ones of said plurality of channels.

22. A method of operating an optical network coupling a plurality of nodes, comprising:

providing a plurality of optical channels, each channel being determined by three variables, a first one of said variables being selected from a plurality of wavelengths, a second one of said variables being selected from a plurality of phases, and a third one of said variables being selected from a plurality of modulation frequencies; and

determining usage status of unused channels of said plurality of optical channels;

dynamically allocating unused ones of said plurality of channels as communication channels in response to requests for channels from said nodes.

23. A method in accordance with claim 22, comprising:

receiving a request from a first node of said plurality of nodes for one of said plurality of channels; and

dynamically allocating a selected one channel of said unused ones of said plurality of channels as a communications channel between said first node and at least a second node of said plurality of nodes.

24. A method in accordance with claim 23, comprising:

changing said usage status of said selected one channel from a first indication to a second indication when said one channel is allocated as a communications channel.

25. A method in accordance with claim 24, comprising:

changing said usage status of said selected one channel back to said first identification after communication between said first node and said at least a second node terminates.

26. A method of operating a fiber optic network coupling a plurality of nodes, comprising:

providing a plurality of optical channels in said fiber optic network, each channel being determined by three variables, a first one of said variables being selected from a plurality of wavelengths, a second one of said variables being selected from a plurality of phases, a third one of said variables being selected from a plurality of modulation frequencies;

providing all of said channels as potential communication channels between all of said nodes;

determining usage status of unused channels of said plurality of optical channels;

selecting an unused one of said plurality of optical channels in dynamic response to a requests for a channel for communication from a first one of said nodes to at least a second one of said nodes, and

performing said selecting step in accordance with a predetermined channel selection algorithm for selecting channels based upon distance to used channels.

27. A method in accordance with claim 26, comprising:

changing said usage status of said selected one channel from unused when said one channel is allocated as a communications channel.

28. A method in accordance with claim 27, comprising:

changing said usage status of said one selected channel back to unused when communication between said first node and said at least a second node terminates.

29. An optical communications system, comprising:

an optical network operable to interconnect a plurality of nodes;

a reference laser source utilized to define a plurality of optical channels, each channel being determined by three variables, a first one of said variables being selected from a plurality of wavelengths, a second one of said variables being selected from a plurality of phases, and a third one of said variables being selected from a plurality of modulation frequencies; and

a processor unit operable to receive requests for channel assignment from said nodes, said processor unit being further operable to identify unused channels of said plurality of optical channels, and dynamically allocating unused ones of said plurality of channels in response to said requests.

30. An optical communications system in accordance with claim 29, comprising:

said processor unit being further operable to receive a request from a first node of said plurality of nodes for allocation of one of said plurality of channels; and

said processor unit dynamically allocating one channel of said unused ones of said plurality of channels as a communications channel between said first node and at least a second node of said plurality of nodes.

31. An optical communications system in accordance with claim 30, comprising:

a memory containing activity information for each channel of said plurality of channels, said activity information being a first state to identify a corresponding channel as being currently allocated and being a second state to identify a current channel as being not currently allocated;

said processor unit changing said activity information of said one channel to said first state when said one channel is allocated as a communications channel.

36. An optical communications system in accordance with claim 30, comprising:

said processor unit selecting said one channel in accordance with a predetermined algorithm.

37. An optical communications system in accordance with claim 30, comprising:

said processor unit selecting said one channel to minimize cross channel interference between said one channel and used ones of said channels.

38. An optical communications system in accordance with claim 30, comprising:

said processor unit selecting said one channel to maximize the distance between said one channel and used ones of said channels.

32. An optical communications system in accordance with clam 31, comprising:

said processor unit changing said activity information of said one channel to said second state channel when communication from said first node and said at least a second node terminates.

33. An optical communications system in accordance with claim 32, comprising:

said processor unit allocating said one channel from said unused ones of said plurality of channels in accordance with a predetermined algorithm.

34. An optical communications system in accordance with claim 32, comprising:

said processor unit selecting said one channel to minimize cross channel interference with used ones of said channels.

35. An optical communications system in accordance with claim 32, comprising:

said processor unit selecting said one channel to maximize the distance between said one channel and used ones of said channels.

39. An optical network, comprising:

a plurality of nodes;

a plurality of optical communications channels, each channel being determined by three variables, a first one of said variables being selected from a plurality of wavelengths, a second one of said variables being selected from a plurality of phases, a third one of said variables being selected from a plurality of modulation frequencies;

processor apparatus utilized to allocate channels of said plurality of communications channels;

memory for identifying channel allocation status; and

said processor utilizing said memory to dynamically allocating unused ones of said plurality of optical channels in response to requests for channels from said nodes.

40. An optical network in accordance with claim 39, comprising:

said processor receiving a request from a first node of said plurality of nodes for one of said plurality of channels; and

said processor being responsive to said request by dynamically allocating one channel of said unused ones of said plurality of channels as a communications channel between said first node and at least a second node of said plurality of nodes.

41. An optical network in accordance with claim 40, comprising:

said processor changing channel allocation status of said one channel from an unused status to an in-use status when said one channel is allocated as a communications channel.

42. An optical network in accordance with claim 41, comprising:

said processor changing said channel allocation status of said one channel back to unused when communication from said first node to said at least a second node terminates.

43. An optical network in accordance with claim 40, comprising:

said processor allocating said one channel in accordance with a predetermined algorithm.

44. An optical network in accordance with claim 40, comprising:

said processor selecting said one channel to maximize the distance between said one channel and used ones of said plurality of channels.

45. An optical network coupling a plurality of nodes, comprising:

a plurality of optical channels, each channel being determined by three variables, a first one of said variables being selected from a plurality of wavelengths, a second one of said variables being selected from a plurality of phases, and a third one of said variables being selected from a plurality of modulation frequencies; and

a processor unit, said processor unit being operated to identify unused channels of said plurality of optical channels, and said processor unit dynamically allocating unused ones of said plurality of channels as communication channels in response to requests for channels from said nodes.

46. A method of operating an optical network coupling a plurality of nodes, comprising:

providing a plurality of optical channels, each channel being determined by a wavelength selected from a plurality of wavelengths, a phase selected from a plurality of phases, and a modulation frequency selected from a plurality of modulation frequencies;

identifying a first usage status for unused channels of said plurality of optical channels; and

dynamically allocating unused ones of said plurality of channels in response to requests for channels from said nodes.

47. A method in accordance with claim 46, comprising:

receiving a request from a first node of said plurality of nodes for allocation of one of said plurality of channels; and

dynamically allocating one channel of said unused ones of said plurality of channels as a communications channel between said first node and at least a second node of said plurality of nodes.

48. A method in accordance with claim 47, comprising:

changing said first usage status to a second usage status of said one channel from said unused ones of said plurality of channels when said one channel is allocated as a communications channel.

49. A method in accordance with claim 48, comprising:

changing said second usage status to said first usage status for said one channel when communication between said first node and said at least a second node terminates.

50. A method in accordance with claim 46, comprising:

selecting said one channel from said unused ones of said plurality of channels in accordance with a predetermined algorithm.

51. A method in accordance with claim 46, comprising:

selecting said one channel to minimize cross channel interference with used ones of said channels.

52. A method in accordance with claim 46, comprising:

selecting said one channel to maximize the distance between said one channel and used ones of said channels.

53. A method in accordance with claim 47, comprising:

selecting said one channel in accordance with a predetermined algorithm.

54. A method in accordance with claim 47, comprising:

selecting said one channel to minimize cross channel interference between said one channel and used ones of said channels.

55. A method in accordance with claim 47, comprising:

selecting said one channel to maximize the distance between said one channel and used ones of said channels.

56. A method in accordance with claim 48, comprising:

selecting said one channel in accordance with a predetermined algorithm.

57. A method in accordance with claim 48, comprising:

selecting said one channel to minimize interference between said one channel and used ones of said channels.

58. A method in accordance with claim 48, comprising:

selecting said one channel to maximize the distance between said one channel and used ones of said channels.

59. A method in accordance with claim 49, comprising:

selecting said one channel for allocation in accordance with a predetermined algorithm.

60. A method in accordance with claim 49, comprising:

selecting said one channel to minimize interference between said one channel and used ones of said channels.

61. A method in accordance with claim 49, comprising:

selecting said one channel to maximize the distance between said one channel and used ones of said channels.

62. An optical communications system, comprising:

an optical network operable to interconnect a plurality of nodes;

a reference laser source utilized to define a plurality of optical channels, each channel being determined by a wavelength selected from a plurality of wavelengths, a phase selected from a plurality of phases, and a modulation frequency selected from a plurality of modulation frequencies; and

a processor unit operable to receive requests for channel assignment from said nodes, said processor unit being further operable to identify unused channels of said plurality of optical channels, and dynamically allocating unused ones of said plurality of channels in response to said requests.

63. An optical communications system in accordance with claim 62, comprising:

said processor unit being further operable to receive a request from a first node of said plurality of nodes for allocation of one of said plurality of channels; and

said processor unit dynamically allocating one channel of said unused ones of said plurality of channels as a communications channel between said first node and at least a second node of said plurality of nodes.

64. An optical communications system in accordance with claim 62, comprising:

a memory containing activity information for each channel of said plurality of channels, said activity information being a first state to identify a corresponding channel as being currently allocated and being a second state to identify a current channel as being not currently allocated;

said processor unit changing said activity information of said one channel to said first state when said one channel is allocated as a communications channel.

69. An optical communications system in accordance with claim 62, comprising:

said processor unit selecting said one channel in accordance with a predetermined algorithm.

70. An optical communications system in accordance with claim 62, comprising:

said processor unit selecting said one channel to minimize cross channel interference between said one channel and used ones of said channels.

71. An optical communications system in accordance with claim 62, comprising:

said processor unit selecting said one channel to maximize the distance between said one channel and used ones of said channels.

65. An optical communications system in accordance with clam 64, comprising:

said processor unit changing said activity information of said one channel to said second state channel when communication from said first node and said at least a second node terminates.

66. An optical communications system in accordance with claim 65, comprising:

said processor unit allocating said one channel from said unused ones of said plurality of channels in accordance with a predetermined algorithm.

67. An optical communications system in accordance with claim 65, comprising:

said processor unit selecting said one channel to minimize cross channel interference with used ones of said channels.

68. An optical communications system in accordance with claim 65, comprising:

said processor unit selecting said one channel to maximize the distance between said one channel and used ones of said channels.