Interconnected broadcast and select optical networks with shared wavelengths

• US 6,895,184 B2
• Filed: 11/21/2001
• Issued: 05/17/2005
• Est. Priority Date: 05/22/2000
• Status: Expired due to Term

• Current Assignee: Snell Holdings, LLC (Treq Labs, Inc.)
• Original Assignee: Opvista, Inc. (Vello Systems Incorporated)
• Inventors: Way, Winston
• Primary Examiner(s): Sedighian, M. R.
• Assistant Examiner(s): Leung, Christina Y.
• Application Number:
  US09/990,196
• Publication Number:
  US 20020067523A1
• Time in Patent Office: 1,273 Days
• Field of Search: 398/3, 398/4, 398/59, 398/79, 398/82, 398/83, 398/84, 398/85
• US Class Current: 398/59
• CPC Class Codes: H04B 10/503 Laser transmitters
• CPC Class Codes: H04B 10/506 Multiwavelength transmitters
• CPC Class Codes: H04B 10/564 Power control
• 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 14/0206 Express channels arrangements
• CPC Class Codes: H04J 14/021 Reconfigurable arrangements, e.g. reconfigurable optical add/drop multiplexers [ROADM] or tunable optical add/drop multiplexers [TOADM]
• CPC Class Codes: H04J 14/0212 using optical switches or wavelength selective switches [WSS]
• CPC Class Codes: H04J 14/0213 Groups of channels or wave bands arrangements
• CPC Class Codes: H04J 14/022 For interconnection of WDM optical networks
• 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 14/0228 Wavelength allocation for communications one-to-all, e.g. broadcasting wavelengths
• CPC Class Codes: H04J 14/0283 WDM ring architectures
• CPC Class Codes: H04J 14/0284 WDM mesh architectures
• CPC Class Codes: H04J 14/0286 WDM hierarchical architectures
• CPC Class Codes: H04J 14/0294 Dedicated protection at the optical channel (1+1)

Abstract

These and other objects of the present invention are achieved in a method of transmitting optical signal traffic. An all optical network is provided with at least two rings that are geographically dispersed. Each ring includes at least one transmitter and at least one receiver. The available wavelengths are separated into distinct ring bands. The optical signal traffic is shared throughout the entire optical network. Each ring is provided with its own distinct ring band of the optical signal traffic. All of the optical signal traffic is transmittable throughout the optical network. Each receiver is configured to receive only wavelengths in a ring band designated for its associated ring.

Claims

1. A method of transmitting optical signal traffic, comprising:

providing an all optical network with at least two rings that are geographically dispersed, each ring including at least one transmitter and at least one receiver;

separating the available wavelengths into distinct ring bands;

sharing the optical signal traffic throughout the entire optical network;

providing each ring with its own distinct ring band of the optical signal traffic, wherein all of the optical signal traffic is transmittable throughout the optical network and each receiver is configured to receive only wavelengths in a ring band designated for its associated ring; and

providing each receiver with a hierarchical mechanism to separate received light at different signal wavelengths within a designated ring band into a plurality of separate optical signals each having a plurality of signal channels and to filter each separate optical signal to extract a selected signal channel.

2. The method of claim 1, wherein all of the ring bands have a same number of optical signals.

3. The method of claim 1, wherein at least a portion of the ring bands have a same number of optical signals.

4. The method of claim 1, wherein all of the ring bands have a different number of optical signals.

5. The method of claim 1, wherein at least a portion of the ring bands have different numbers of optical signals.

6. The method of claim 1, wherein none of the ring bands shares a common wavelength with another ring band.

7. The method of claim 1, wherein all of the optical network traffic is included in the ring bands.

8. The method of claim 1, wherein each ring includes at least two nodes.

9. The method of claim 8, wherein each node includes at least one transmitter and one receiver.

10. The method of claim 1, wherein each ring in the optical network includes at least a first and a second fiber with all of the optical signal traffic traveling in both of the first and second fibers, wherein the optical signal traffic travels in a clockwise direction in the first fiber and in a counter-clockwise direction in the second fiber.

11. The method of claim 10, wherein the first and second fibers are each coupled to a 1×

1 or 1×

2 switch.

12. The method of claim 11, further comprising:

maintaining the 1×

1 or 1×

2 switch in an open position when there is no break point in an associated ring, and closing the 1×

1 or 1×

2 switch upon an occurrence of a break point in the associated ring.

13. The method of claim 12, further comprising:

discovering a break point in an ring by monitoring an optical supervision signal that travels through the associated ring.

14. The method of claim 10, wherein at least one of the two rings comprises a central hub optically coupled to the first and second fibers to include a first hub optical switch in the first fiber and a second hub optical switch in the second fiber, the method further comprising:

opening the first hub optical switch to create a break point when there is no other break point in the first fiber; and

closing the first hub optical switch when there is a break point in the first fiber.

15. The method of claim 10, wherein at least one of the two rings comprises a central hub optically coupled to the first and second fibers to include a first hub optical switch in the first fiber and a second hub optical switch in the second fiber, the method further comprising:

operating each of the first and second hub optical switches to maintain a break point in each of the first and second fibers.

16. The method of claim 10, wherein at least one of the two rings comprises a central hub optically coupled to the first and second fibers to include a first hub optical switch in the first fiber and a second hub optical switch in the second fiber, and wherein the first fiber ring comprises as optical switch outside the central hub,

the method further comprising:

opening the optical switch outside the central hub to maintain a break point in the first fiber when the first hub optical switch in the central hub is closed; and

closing the first optical switch outside the central hub while keeping the first hub optical switch in the central hub closed when there is a break in the first fiber.

17. The method of claim 16, wherein the optical switch outside the central hub is located in a node coupled to the first and the second fibers.

18. The method of claim 1, wherein the optical network includes a 1×

2 band-splitter and a 2×

1 coupler that couples the optical signal traffic between the at least two rings.

19. The method of claim 18, further comprising:

coupling the optical signal traffic between the at least two rings through the 1×

2 band-splitter and the 2×

1 coupler.

20.The method of claim 1, wherein each ring in the optical network includes a fiber with the same signal traffic duplicated in two different bands that travel in both clockwise and counter-clockwise directions.

20. The method of claim 1, wherein the optical network includes, first, second and third rings, each ring including a first and a seond protection fibers with all of the optical signal traffic traveling in both of the first and second protection fibers, wherein the optical signal traffic travels in a clockwise direction in the first protection fiber and in a counter-clockwise direction in the second protection fiber.

22. The method of claim 1, wherein the optical network further includes a first and second M×

M optical switches, where M is the total number of ring bands.

24. The method of claim 1, further comprising using a tunable laser in the at least one transmitter in each ring to launch a dynamically tunable wavelength into the optical network.

26. The method of claim 1, further comprising using a tunable optical filter in the at least one receiver in each ring to form a dynamic wavelength-tunable receiver.

21. The method of claim 21, wherein each of the first and second protection fibers is coupled to a 1×

1 switch.

23. The method of claim 23, further comprising:

coupling the optical signal traffic between the at least first and second rings with the first and second M×

M switches, wherein the first M×

M switch routes the optical signal traffic in a clockwise direction, and the second M×

M switch routes the optical signal traffic in a counter-clockwise direction.

25. The method of claim 25, further comprising using a tunable optical filter in the at least one receiver in each ring to form a dynamic wavelength-tunable receiver.

27. A method of transmitting optical traffic, comprising:

providing an all optical network with at least two rings that are geographically dispersed, each ring including at least one transmitter and at least one receiver;

sharing a sufficiently large enough number of wavelengths in the at least two rings to eliminate O-E-O conversions between the rings;

sharing the optical signal traffic throughout the entire optical network;

providing each ring with its own distinct ring band of the optical signal traffic, wherein all of the optical signal traffic is transmittable throughout the optical network and each receiver is configured to receive only wavelengths in a ring band designated for its associated ring; and

providing each receiver with a hierarchical mechanism to separate received light into a plurality of separate optical signals each having a plurality of channels and to filter each separate optical signal to extract a selected channel.

28. The method of claim 28, wherein all of the ring bands have a same number of optical signals.

29. The method of claim 28, wherein at least a portion of the ring bands have a same number of optical signals.

30. The method of claim 28, wherein all of the ring bands have a different number of optical signals.

31. The method of claim 28, wherein at least a portion of the ring bands have different numbers of optical signals.

32. The method of claim 28, wherein none of the ring bands shares a common wavelength with another ring band.

33. The method of claim 28, wherein all of the optical network traffic is included in the ring bands.

34. The method of claim 28, wherein each ring includes at least two nodes.

35. The method of claim 28, wherein each node includes at least one transmitter and one receiver.

36. The method of claim 28, wherein each ring in the optical network includes at least a first and a second fibers with all of the optical signal traffic traveling in both of the first and second fibers, wherein the optical signal traffic travels in a clockwise direction in the first fiber and in a counter-clockwise direction in the second fiber.

40. The method of claim 28, wherein the optical network includes a 1×

2 band-splitter and a 2×

1 coupler that couples the optical signal traffic between the at least two rings.

42. The method of claim 28, wherein each ring in the optical network includes a fiber with the same signal traffic duplicated in two different bands that travel in both clockwise and counter-clockwise directions.

43. The method of claim 28, wherein the optical network includes, first, second and third rings, each ring including a first and a second protection fibers with all of the optical signal traffic traveling in both of the first and second protection fibers, wherein the optical signal traffic travels in a clockwise direction in the first protection fiber and in a counter-clockwise direction in the second protection fiber.

45. The method of claim 28, wherein the optical network further includes a first and second M×

M optical switches, where M is the total number of ring bands.

37. The method of claim 37, wherein the first and second fibers are each coupled to a 1×

1 or 1×

2 switch.

38. The method of claim 38, further comprising:

maintaining the 1×

1 or 1×

2 switch in an open position when there is no break point in an associated ring, and closing the 1×

1 or 1×

2 switch upon an occurrence of a break point in the associated ring.

39. The method of claim 39, further comprising:

discovering a break point in an ring by monitoring an optical supervision signal that travels through the associated ring.

41. The method of claim 41, further comprising:

coupling the optical signal traffic between the at least two rings through the 1×

2 band-splitter and the 2×

1 coupler.

44. The method of claim 44, wherein each of the first and second protection fibers is coupled to a 1×

1 switch.

46. The method of claim 46, further comprising:

coupling the optical signal traffic between the at least first and second rings with the first and second M×

M switches, wherein the first M×

M switch routes the optical signal traffic in a clockwise direction, and the second M×

M switch routes the optical signal traffic in a counter-clockwise direction.

47. A method of transmitting optical signal traffic, comprising:

providing an all optical network with hierarchical rings, each hierarchical ring including a plurality of nodes and each node including at least one transmitter and one receiver;

separating the optical signal traffic into ring bands;

transmitting the optical signal traffic through all of the hierarchical rings; and

providing each hierarchical ring with its own distinct ring band, wherein all of the available wavelengths are transmittable throughout each hierarchical ring, and the receivers of a hierarchical ring are configured to receive only wavelengths in a ring band that is designated for that hierarchical ring.

48. The method of claim 48, further comprising using a tunable laser in the at least one transmitter in a node to launch a dynamically tunable wavelength into the optical network.

50. The method of claim 48, further comprising using a tunable optical filter in the at least one receiver in one node to form a dynamic wavelength-tunable receiver.

49. The method of claim 49, further comprising using a tunable optical filter in the at least one receiver in at least one of the nodes to form a dynamic wavelength-tunable receiver.

51. An all optical network for optical signal traffic, comprising:

at least a first and a second ring, each ring having at least one transmitter and one receiver and its own distinct ring band of the optical signal traffic, wherein all of the optical signal traffic is transmittable throughout the entire all optical network and each receiver is configured to receive only wavelengths in a ring band designated for its associated ring; and

a central hub that couples the at least first and second rings, the central hub separating the optical signal traffic into ring bands,

wherein each receiver in each ring comprises a hierarchical mechanism which comprises at least one optical element operable to separate received light into a plurality of separate optical signals each having a plurality of signal channels, and a plurality of optical filters optically coupled to receive and filter the separate optical signals, respectively, to extract respective selected signal channels.

52. The all optical network of claim 52, wherein each ring includes at least a first and a second protection fibers that carry all of the optical signal traffic, wherein the optical signal traffic travels in a clockwise direction in the first protection fiber and in a counter-clockwise direction in the second protection fiber.

55. The all optical network of claim 52, wherein the central hub includes at least one 1×

2 band-splitter and a 2×

1 coupler that couple the optical signal traffic between the at least first and second rings.

56. The all optical network of claim 52, further comprising:

first and second M×

M optical switches, where M is the total number of ring bands.

57. The all optical network of claim 52, wherein each ring includes multiple nodes.

59. The all optical network of claim 52, further comprising:

at least one mesh-based long haul network coupled to the at least first and second rings.

60. The all optical network of claim 52, wherein the at least first and second rings are geographically dispersed.

61. The all optical network of claim 52, wherein the at least first and second rings are hierarchical rings.

62. The all optical network of claim 52, wherein each of the at least first and second rings includes a 2×

1 coupler for adding traffic and a 1×

2 coupler for dropping traffic.

64. The all optical network of claim 52, wherein all of the ring bands have a same number of optical signals.

65. The all optical network of claim 52, wherein at least a portion of the ring bands have a same number of optical signals.

66. The all optical network of claim 52, wherein all of the ring bands have a different number of optical signals.

67. The all optical network of claim 52, wherein at least a portion of the ring bands have different numbers of optical signals.

68. The all optical network of claim 52, wherein none of ring bands share common wavelengths.

69. The all optical network of claim 52, wherein all of the optical network traffic is included in the ring bands.

53. The all optical network of claim 53 wherein at least one 1×

1 or 1×

2 switch is coupled to each of the first and second protection fibers.

54. The all optical network of claim 54, wherein each 1×

1 or 1×

2 switch is maintained in an open position when there is no break point in an associated ring, and each 1×

1 or 1×

2 switch is closed upon an occurrence of a break point in the associated ring.

58. The all optical network of claim 58, wherein each node includes at least one transmitter and one receiver.

63. The all optical network of claim 63, further comprising:

a broadband gain-equalizer and a gain-clamped optical amplifier positioned between the first 2×

1 coupler and the second 1×

2 coupler of the at least first and second rings.