Frame structure and method for wavelength concatenated channel framing

1. A method, comprising:

generating, using a framing unit, a frame having a frame structure, wherein

the frame structure comprises information regarding a super-channel comprised of one or more sub-channels, and

said generating the frame further comprises:

inserting a primary super-channel identifier into the frame structure, wherein the primary super-channel identifier identifies a primary super-channel associated with the frame structure, and

inserting a sub-channel identifier into the frame structure, wherein

the sub-channel identifier identifies a sub-channel of the primary super-channel,

the sub-channel identifier identifies a sub-channel associated with the frame structure, and

the sub-channel identifier comprises an active bit identifying whether the sub-channel can transmit data.

2. The method of claim 1 , wherein

the primary super-channel identifier identifies the frame structure as an Alarm Indication Signal (AIS) frame.

3. The method of claim 1 wherein generating the frame further comprises:

inserting a frame counter into the frame structure, wherein

the frame counter uniquely identifies the frame at a the time the frame is generated.

4. The method of claim 3 , wherein

the frame counter is reset when a first frame is generated and when the frame counter reaches a maximum value.

5. The method of claim 3 wherein generating the frame further comprises:

inserting an alternate super-channel identifier into the frame structure.

6. The method of claim 5 , wherein

the alternate super-channel identifier identifies an alternate super-channel on which to transmit the frame structure.

7. The method of claim 6 wherein generating the frame further comprises:

generating a super-channel sub-channel bitmap, wherein

the super-channel is one of the primary super-channel and the alternate super-channel, and

the bitmap provides a status of each sub-channel that comprises the super-channel; and

inserting the super-channel sub-channel bitmap into the frame structure.

8. The method of claim 7 wherein generating the super-channel sub-channel bitmap comprises for each sub-channel that comprises the super-channel:

selecting a sub-channel that comprises the super-channel;

determining whether the selected sub-channel is degraded;

upon a determination that the selected sub-channel is degraded, setting a status flag corresponding to the selected sub-channel; and

upon a determination that the selected sub-channel is not degraded, clearing the status flag corresponding to the selected sub-channel.

9. The method of claim 8 , wherein

the super-channel sub-channel bitmap is generated for each of the primary super-channel and the alternate super-channel.

10. The method of claim 9 wherein generating the frame further comprises:

generating an error flag field, wherein

the error flag field corresponds to the sub-channel upon which the frame structure is transmitted; and

inserting the error flag field into the frame structure.

11. The method of claim 10 wherein generating the error flag field comprises:

determining whether the sub-channel is to be forced to switch;

upon a determination that the sub-channel is to be forced to switch, setting a forced/manual switch flag in the error flag field; and

upon a determination that the sub-channel is not to be forced to switch, clearing the forced/manual switch flag.

12. The method of claim 11 wherein generating the error flag field further comprises:

determining whether a bit error rate (BER) for the sub-channel is above a threshold;

upon a determination that the BER for the sub-channel is above the threshold, setting a BER flag in the error flag field; and

upon a determination that the BER for the sub-channel is not above the threshold, clearing the BER flag.

13. The method of claim 11 wherein generating the error flag field further comprises:

determining whether a loss-of-signal (LOS) has occurred on the sub-channel;

upon a determination that a LOS has occurred, setting a LOS flag in the error flag field; and

upon a determination that a LOS has not occurred, clearing the LOS flag.

14. The method of claim 11 wherein generating the error flag field further comprises:

determining whether a loss-of-frame (LOF) has occurred on the sub-channel;

upon a determination that a LOF has occurred, setting a LOF flag in the error flag field; and

upon a determination that a LOF has not occurred, clearing the LOF flag.

15. The method of claim 11 wherein generating the error flag field further comprises:

determining whether a cyclic redundancy check (CRC) error has occurred on the sub-channel;

upon a determination that a CRC error has occurred, setting a CRC error flag in the error flag field; and

upon a determination that a CRC error has not occurred, clearing the CRC error flag.

16. The method of claim 11 wherein generating the error flag field further comprises:

determining whether to generate a remote defect indicate (RDI) in response to receipt of an alarm indication signal;

upon a determination that a RDI needs to be generated, setting an RDI flag in the error flag field; and

upon a determination that a RDI does not need to be generated, clearing the RDI flag.

17. The method of claim 11 wherein generating the frame further comprises:

generating a label-switched path (LSP) switch field for each of the primary super-channel and the alternate super-channel; and

inserting the LSP switch field into the frame structure.

18. The method of claim 17 wherein generating the LSP switch field comprises:

determining whether a super-channel needs configuring, wherein

the super-channel is one of the primary super-channel and alternate super-channel;

in response to a determination that the super-channel needs configuring,

determining a number of sub-channels that comprise the super-channel that are functional,

using the number of functional sub-channels that comprise the super-channel to determine an amount of guaranteed bandwidth traffic that can be accepted for the super-channel, and

using the amount of guaranteed bandwidth traffic that can be accepted for the super-channel, to determine the LSP switch field value.

19. The method of claim 18 wherein determining the LSP switch field value comprises:

monitoring the primary super-channel for error conditions in the sub-channels that comprise the super-channel;

in response to a number of error conditions in the sub-channels exceeding a threshold,

setting the LSP switch field to a value corresponding to alternate operation,

wherein

alternate operation comprises switching guaranteed bandwidth traffic to the alternate super-channel,

wherein,

the threshold corresponds to a number of error conditions in the sub-channels sufficient to cause the bandwidth of the primary super-channel to be insufficient to provide the guaranteed bandwidth;

in response to a number of error conditions on the primary super-channel being less than the threshold,

setting the LSP switch field to a value corresponding to normal operation.

20. The method of claim 19 wherein monitoring the primary super-channel for error conditions in the sub-channels that comprise the super-channel comprises:

analyzing the super-channel sub-channel bitmap corresponding to the primary super-channel.

21. The method of claim 17 wherein generating the frame further comprises:

inserting payload data units into the frame structure.

22. The method of claim 21 wherein generating the frame further comprises:

inserting a byte-interleaved parity value (BIP8 value) calculated for a previously generated frame into the frame structure.

23. A network device comprising:

a frame generator configured to:

generate a frame having a frame structure, wherein

the frame structure comprises information regarding a super-channel comprised of one or more sub-channels,

insert a primary super-channel identifier into the frame structure,

insert a sub-channel identifier into the frame structure, and

insert a frame counter into the frame structure, wherein

the frame counter uniquely identifies the frame at about a time the frame is generated,

the primary super-channel identifier identifies a primary super-channel associated with the frame structure,

the sub-channel identifier identifies a sub-channel associated with the frame structure, and

the sub-channel identifier identifies a sub-channel of the primary super-channel.

24. The network device of claim 23 wherein the frame generator is further configured to

insert an alternate super-channel identifier into the frame structure.

25. The network device of claim 24 , wherein

the alternate super-channel identifier identifies an alternate super-channel on which to transmit the frame structure.

26. The network device of claim 25 wherein the frame generator is further configured to

generate a super-channel sub-channel bitmap, wherein

the super-channel is one of the primary super-channel and the alternate super-channel, and

the bitmap provides a status of each sub-channel that comprises the super-channel; and

insert the super-channel sub-channel bitmap into the frame structure.

27. The network device of claim 26 , wherein

each bit in the super-channel sub-channel bitmap represents an operational state of a corresponding sub-channel.

28. The network device of claim 27 , wherein

the super-channel sub-channel bitmap is generated for each of the primary super-channel and the alternate super-channel.

29. The network device of claim 28 wherein the frame generator is further configured to

generate an error flag field, wherein

the error flag field corresponds to the sub-channel upon which the frame structure is transmitted; and

insert the error flag field into the frame structure.

30. The network device of claim 29 , wherein the error flag field comprises:

a bit error rate flag;

a loss-of-signal flag;

a loss-of-frame flag; and

a cyclic redundancy check error flag.

31. The network device of claim 30 , wherein the error flag field further comprises:

a remote defect indicate flag.

32. The network device of claim 29 wherein the frame generator is further configured to

generate a label-switched path (LSP) switch field for each of the primary super-channel and the alternate super-channel; and

insert the LSP switch field into the frame structure.

33. The network device of claim 32 , wherein

the LSP switch field is configured to indicate which of the primary super-channel and the alternate super-channel should carry a guaranteed bandwidth data signal.

34. The network device of claim 32 wherein the frame generator is further configured to

insert a payload data unit into the frame structure.

35. The network device of claim 34 wherein the frame generator is further configured to

insert a byte-interleaved parity value calculated for a previously generated frame into the frame structure.

36. An apparatus comprising:

means for generating a frame having a frame structure, wherein

the frame structure comprises information regarding a super-channel comprised of one or more sub-channels;

means for inserting a primary super-channel identifier into the frame structure;

means for inserting a sub-channel identifier into the frame structure;

means for inserting a frame counter into the frame structure, wherein

the sub-channel identifier identifies a sub-channel of the primary super-channel,

the sub-channel identifier identifies a sub-channel associated with the frame structure,

the primary super-channel identifier identifies a primary super-channel associated with the frame structure, and

the frame counter uniquely identifies the frame at about a time the frame is generated.

37. The apparatus of claim 36 , wherein

the primary super-channel identifier identifies the frame structure as an Alarm Indication Signal (AIS) frame.

38. The apparatus of claim 36 , wherein the means for inserting a frame counter further comprises:

means for resetting the frame counter when a first frame is generated and when the frame counter reaches a maximum value.

39. The apparatus of claim 36 wherein the means for generating a frame further comprises:

means for inserting an alternate super-channel identifier into the frame structure.

40. The apparatus of claim 39 , wherein

the alternate super-channel identifier identifies an alternate super-channel on which to transmit the frame structure.

41. The apparatus of claim 40 wherein the means for generating a frame further comprises:

means for generating a super-channel sub-channel bitmap, wherein

the super-channel is one of the primary super-channel and the alternate super-channel, and

the bitmap provides a status of each sub-channel that comprises the super-channel; and

means for inserting the super-channel sub-channel bitmap into the frame structure.

42. The apparatus of claim 41 wherein the means for generating a super-channel sub-channel bitmap comprises:

means for selecting a sub-channel that comprises the super-channel;

means for determining whether the selected sub-channel is degraded;

means, responsive to a determination that the selected sub-channel is degraded, for setting a status flag corresponding to the selected sub-channel; and

means, responsive to a determination that the selected sub-channel is not degraded, for clearing the status flag corresponding to the selected sub-channel.

43. The apparatus of claim 41 wherein the means for generating a frame further comprises:

means for generating an error flag field, wherein

the error flag field corresponds to the sub-channel upon which the frame structure is transmitted; and

means for inserting the error flag field into the frame structure.

44. The apparatus of claim 43 wherein the means for generating the error flag field comprises:

means for determining whether the sub-channel is to be forced to switch;

means, responsive to a determination that the sub-channel is to be forced to switch, for setting a forced/manual switch flag in the error flag field; and

means, responsive to a determination that the sub-channel is not to be forced to switch, for clearing the forced/manual switch flag.

45. The apparatus of claim 44 wherein the means for generating the error flag field further comprises:

means for determining whether a bit error rate (BER) for the sub-channel is above a threshold;

means, responsive to a determination that the BER for the sub-channel is above the threshold, for setting a BER flag in the error flag field; and

means, responsive to a determination that the BER for the sub-channel is not above the threshold, for clearing the BER flag.

46. The apparatus of claim 44 wherein the means for generating the error flag field further comprises:

means for determining whether a loss-of-signal (LOS) has occurred on the sub-channel;

means, responsive to a determination that a LOS has occurred, for setting a LOS flag in the error flag field; and

means, responsive to a determination that a LOS has not occurred, for clearing the LOS flag.

47. The apparatus of claim 44 wherein the means for generating the error flag field further comprises:

means for determining whether a loss-of-frame (LOF) has occurred on the sub-channel;

means, responsive to a determination that a LOF has occurred, for setting a LOF flag in the error flag field; and

means, responsive to a determination that a LOF has not occurred, for clearing the LOF flag.

48. The apparatus of claim 44 wherein the means for generating the error flag field further comprises:

means for determining whether a cyclic redundancy check (CRC) error has occurred on the sub-channel;

means, responsive to a determination that a CRC error has occurred, for setting a CRC error flag in the error flag field; and

means, responsive to a determination that a CRC error has not occurred, for clearing the CRC error flag.

49. The apparatus of claim 44 wherein the means for generating the error flag field further comprises:

means for determining whether to generate a remote defect indicate (RDI) in response to receipt of an alarm indication signal;

means, responsive to a determination that a RDI needs to be generated, for setting an RDI flag in the error flag field; and

means, responsive to a determination that a RDI does not need to be generated, for clearing the RDI flag.

50. The apparatus of claim 44 wherein the means for generating the frame further comprises:

means for generating a label-switched path (LSP) switch field for each of the primary super-channel and the alternate super-channel; and

means for inserting the LSP switch field into the frame structure.

51. The apparatus of claim 50 wherein the means for generating the LSP switch field comprises:

means for determining whether a super-channel needs configuring, wherein

the super-channel is one of the primary super-channel and alternate super-channel; and

means, responsive to a determination that the super-channel needs configuring,

for determining a number of sub-channels that comprise the super-channel that are functional,

for determining an amount of guaranteed bandwidth traffic that can be accepted for the super-channel, using the number of functional sub-channels that comprise the super-channel, and

for determining the LSP switch field value, using the amount of guaranteed bandwidth traffic that can be accepted for the super-channel.

52. The apparatus of claim 51 wherein the means for determining the LSP switch field value comprises:

means for monitoring the primary super-channel for error conditions in the sub-channels that comprise the super-channel;

means, responsive to a number of error conditions in the sub-channels exceeding a threshold, for setting the LSP switch field to a value corresponding to alternate operation, wherein

alternate operation comprises switching guaranteed bandwidth traffic to the alternate super-channel,

wherein,

the threshold corresponds to a number of error conditions in the sub-channels sufficient to cause the bandwidth of the primary super-channel to be insufficient to provide the guaranteed bandwidth;

means, responsive to a number of error conditions on the primary super-channel being less than the threshold, for setting the LSP switch field to a value corresponding to normal operation.

53. The apparatus of claim 52 wherein the means for monitoring the primary super-channel for error conditions in the sub-channels that comprise the super-channel comprises:

means for analyzing the super-channel sub-channel bitmap corresponding to the primary super-channel.

54. The apparatus of claim 50 wherein the means for generating the frame further comprises:

means for inserting payload data units into the frame structure.

55. The apparatus of claim 54 wherein the means for generating the frame further comprises:

means for inserting a byte-interleaved parity value (BIP8 value) calculated for a previously generated frame into the frame structure.