Verifying Configuration in Wavelength Selective Switching Node

• US 20180175962A1
• Filed: 06/17/2015
• Published: 06/21/2018
• Est. Priority Date: 06/17/2015
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Magri, Roberto, Constantini, Matteo
• Granted Patent: US 10,313,046 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 10/07 Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
• CPC Class Codes: H04J 14/0212 using optical switches or wavelength selective switches [WSS]
• CPC Class Codes: H04J 14/02122 Colourless, directionless or contentionless [CDC] arrangements
• CPC Class Codes: H04J 14/0217 Multi-degree architectures, e.g. having a connection degree greater than two
• CPC Class Codes: H04J 14/0221 Power control, e.g. to keep the total optical power constant
• CPC Class Codes: H04Q 11/0005 Switch and router aspects

Abstract

Verifying a configuration of reconfigurable internal optical paths (970) in a wavelength selective optical switching WSS node (62) involves identifying which of several WSS subsystems (920, 950, 960) is coupled upstream of a first internal optical path based on detecting optical power distinctive of the upstream subsystem and carried to the downstream WSS subsystem. The detecting can be of a power of wavelengths used for traffic (110), or a power of optical noise when there is no traffic (120). A record is made of the identified configuration. The automated verification can be carried out without the conventional dedicated optical wavelengths or dedicated optical hardware for inserting such additional wavelengths dedicated to discovery, and without disrupting the traffic if upgrading a node. It can be controlled locally or by an NMS such as an SDN controller.

Claims

1-32. -32. (canceled)

33. A method of verifying a configuration of reconfigurable internal optical paths in a wavelength selective optical switching node having at least two wavelength selective switching (WSS) subsystems, each subsystem having at least two internal ports and being configured such that an internal optical path carries traffic from an internal port of an upstream one of the subsystems to an internal port of a downstream one of the subsystems, the method comprising:

identifying a configuration comprising the upstream subsystem and the internal port of the downstream subsystem that are coupled to the internal optical path, based on detecting optical power distinctive of the upstream subsystem and carried to the downstream subsystem, the detecting comprising detecting the distinctive optical power by at least one of;

detecting a power of wavelengths used for traffic, and detecting a power of optical noise when there is no traffic, and

making a record of the identified configuration of the internal port of the downstream subsystem coupled to the identified upstream subsystem via the internal optical path.

34. The method of claim 33, wherein identifying the configuration is based on detecting the power of wavelengths also used for traffic.

35. The method of claim 34, wherein identifying the configuration is based on detecting the power of wavelengths by at least one of:

detecting a distinctive pattern of which wavelengths are in use, and detecting a distinctive optical power modulation applied to enable the verification.

36. The method of claim 33, wherein identifying the configuration is based on detecting the distinctive optical power in the form of optical noise when there is no traffic, at a time when no such noise is being output from others of the subsystems.

37. The method of claim 33, wherein:

the internal optical path is bidirectional between the upstream and downstream subsystems; and

identifying the configuration is based on detecting the distinctive optical power carried by the internal optical path in one of the directions by detecting a power of wavelengths used for traffic, and based on detecting, in the other direction, the distinctive optical power by detecting a power of optical noise when there is no traffic.

38. The method of claim 33, further comprising configuring the upstream subsystem to broadcast the distinctive optical power to more than one of its internal ports, wherein identifying the configuration is based on detecting at different ones of the downstream subsystem'"'"'s internal ports.

39. The method of claim 33, further comprising configuring the upstream subsystem to route the distinctive optical power to different ones of the upstream subsystem'"'"'s internal ports for respective defined periods.

40. The method of claim 33, wherein identifying the configuration comprises comparing the detected distinctive optical power to a known optical power output by the upstream subsystem.

41. The method of claim 33, further comprising:

if detecting the optical power produces an ambiguity, causing an unambiguous optical power to be output from the upstream subsystem over the internal optical path.

42. The method of claim 33, further comprising controlling nodes upstream of the upstream subsystem to route a temporarily unused wavelength to the downstream subsystem to provide additional distinctiveness of the optical power.

43. The method of claim 33, further comprising controlling an optical amplifier at the upstream subsystem to provide the distinctive optical power without providing an additional dedicated optical wavelength.

44. The method of claim 33, further comprising using the identified configuration to identify an incorrect configuration.

45. The method of claim 33, wherein the method is carried out by a network management system.

46. Apparatus for verifying a configuration of reconfigurable internal optical paths in a wavelength-selective optical switching node having at least two wavelength selective switching (WSS) subsystems, each subsystem having at least two internal ports and being configured such that an internal optical path carries traffic from an internal port of an upstream one of the subsystems to an internal port of a downstream one of the subsystems, the apparatus comprising:

a processing circuit; and

a memory circuit storing computer-executable instructions that, when executed by the processor circuit, configure the apparatus to;

identify a configuration comprising the upstream subsystem and the internal port of the downstream subsystem that are coupled to the internal optical path, based on detecting optical power distinctive of the upstream subsystem and carried to the downstream subsystem, the detecting comprising at least one of;

detecting a power of wavelengths used for traffic, and detecting a power of optical noise when there is no traffic, and

make a record of the identified configuration of the internal port of the downstream subsystem coupled to the identified upstream subsystem via the internal optical path.

47. The apparatus of claim 46, wherein execution of the instructions further configures the apparatus to identify the configuration based on detecting the power of wavelengths also used for traffic, by at least one of:

using an optical channel monitor to detect the pattern as a pattern of which wavelengths are in use, and using an optical power detector to detect the pattern as a pattern of optical power modulation applied to enable the verification.

48. The apparatus of claim 46, wherein:

the internal optical path is bidirectional between the upstream and downstream subsystems; and

execution of the instructions further configures the apparatus to identify the configuration based on detecting the distinctive optical power carried by the internal optical path in one of the directions by detecting a power of wavelengths used for traffic, and based on detecting, in the other direction, the distinctive optical power by detecting a power of optical noise when there is no traffic.

49. The apparatus of any of claim 46, the upstream subsystem being configured to broadcast the distinctive optical power to its internal ports, wherein execution of the instructions further configures the apparatus to identify the configuration based on detecting at different ones of the downstream subsystem'"'"'s internal ports.

50. The apparatus of any of claim 46, wherein execution of the instructions further configures the apparatus to control nodes upstream of the upstream subsystem to route the distinctive optical power to different ones of the upstream subsystem'"'"'s internal ports for respective defined periods.

51. The apparatus of claim 46, wherein execution of the instructions further configures the apparatus to, in the case of ambiguity in the detecting, control the upstream subsystem to output an unambiguous distinctive optical power over the internal optical path.

52. The apparatus of claim 46, wherein execution of the instructions further configures the apparatus to compare the detected distinctive optical power to a known optical power output by the upstream subsystem.

53. A network management system comprising the apparatus of claim 46.

54. A controller for a node comprising the apparatus of claim 46.

55. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by a processing unit, configure an apparatus to perform operations comprising:

identifying a configuration comprising the upstream subsystem and the internal port of the downstream subsystem that are coupled to the internal optical path, based on detecting optical power distinctive of the upstream subsystem and carried to the downstream subsystem, the detecting comprising detecting the distinctive optical power by at least one of;

detecting a power of wavelengths used for traffic, and detecting a power of optical noise when there is no traffic, and

making a record of the identified configuration of the internal port of the downstream subsystem coupled to the identified upstream subsystem via the internal optical path.