Method and apparatus for regenerating optical signals in an all-optical cross-connect switch

• US 6,944,364 B2
• Filed: 08/27/2003
• Issued: 09/13/2005
• Est. Priority Date: 11/02/1999
• Status: Expired due to Fees

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Ward, Robert R., Ramaswami, Rajiv
• Primary Examiner(s): HEALY, BRIAN
• Application Number:
  US10/648,956
• Publication Number:
  US 20040258408A1
• Time in Patent Office: 748 Days
• Field of Search: 385/16, 385/17, 385/18, 385/24, 385/88, 385/89, 398/45, 398/46, 398/49, 398/50, 398/56, 398/57, 398/48
• US Class Current: 385/17
• CPC Class Codes: G02B 6/43 Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections
• CPC Class Codes: H04J 14/0293 Optical channel protection
• CPC Class Codes: H04J 14/0297 Optical equipment protection
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 11/0062 Network aspects
• CPC Class Codes: H04Q 2011/0009 using wavelength filters
• CPC Class Codes: H04Q 2011/0015 using splitting combining
• CPC Class Codes: H04Q 2011/0024 using space switching
• CPC Class Codes: H04Q 2011/0026 using free space propagation (e.g. lenses, mirrors)
• CPC Class Codes: H04Q 2011/0035 using miscellaneous components, e.g. circulator, polarisation, acousto/thermo optical
• CPC Class Codes: H04Q 2011/0041 Optical control
• CPC Class Codes: H04Q 2011/0043 Fault tolerance
• CPC Class Codes: H04Q 2011/005 Arbitration and scheduling
• CPC Class Codes: H04Q 2011/0058 Crossbar; Matrix
• CPC Class Codes: H04Q 2011/0073 Provisions for forwarding or routing, e.g. lookup tables
• CPC Class Codes: H04Q 2011/0081 Fault tolerance; Redundancy; Recovery; Reconfigurability
• CPC Class Codes: H04Q 2011/0083 Testing; Monitoring
• CPC Class Codes: H04Q 2011/0088 Signalling aspects

Abstract

Methods, apparatus and systems for regenerating, monitoring and bridging optical signals through an optical cross-connect switch to provide increased reliability. A self testing method, apparatus and system for an optical cross-connect switch. An optical-to-electrical-to-optical converter (O/E/O) is provided in an optical cross-connect switch to provide optical-electrical-optical conversion. I/O port cards having an optical-to-electrical-to-optical converter are referred to as smart port cards while I/O port cards without an optical-to-electrical-to-optical converter are referred to as passive port cards. Test port/monitor cards are also provided for testing optical cross-connect switches. Methods, apparatus and systems for performing bridging, test access, and supporting redundant optical switch fabrics are also disclosed.

Claims

1. A method of regenerating optical signals in an all-optical cross-connect switch, the method comprising:

providing one or more smart port cards, each of the one or more smart port cards including an optical-electrical-optical converter in an optical path, the optical-electrical-optical converter to convert an input optical signal into an electrical signal and the electrical signal into an output optical signal, the output optical signal being responsive to the input optical signal;

providing one or more passive port cards, the one or more passive port cards without an optical-electrical-optical converter; and

generating an optical path through an optical switch fabric of optical switches for optical signals to flow between the one or more smart port cards and the one or more passive port cards.

2. The method of claim 1 wherein

the optical-electrical-optical converter is in the input optical path of each of the one or more smart port cards;

and

the generating of the optical path through the optical switch fabric couples the input optical path of the smart port cards to the output optical path of the passive port cards.

3. The method of claim 1 wherein

the optical-electrical-optical converter is in the output optical path of each of the one or more smart port cards;

and

the generating of the optical path through the optical switch fabric couples the input optical path of the passive port cards to the output optical path of the smart port cards.

4. The method of claim 1 wherein

the optical-electrical-optical converter monitors the optical signal.

5. An apparatus for regenerating optical signals in an all-optical cross-connect switch, the apparatus comprising:

a smart port card, the smart port card including

an optical-electrical-optical converter in an optical path, the optical-electrical-optical converter to convert an input optical signal into an electrical signal and the electrical signal into an output optical signal.

6. The apparatus of claim 5 wherein

the output optical signal is substantially similar to the input optical signal.

7. The apparatus of claim 5 wherein

the optical-electrical-optical converter provides wavelength conversion such that the output optical signal has substantially similar information content as that of the input optical signal but a differing photonic wavelength.

8. The apparatus of claim 5 wherein

the optical-electrical-optical converter is in the input optical path of the smart port card.

9. The apparatus of claim 5 wherein

the optical-electrical-optical converter is in the output optical path of the smart port card.

10. The apparatus of claim 5 wherein

the optical-electrical-optical converter provides a tap to the electrical signal to monitor the optical signal.

11. A method of regenerating optical signals in an all-optical cross-connect switch, the method comprising:

converting a first optical signal into an electrical signal;

converting the electrical signal into a second optical signal, the second optical signal being responsive to the first optical signal; and

forming an optical path through an optical switch fabric of optical switches over which optical signals can be transported through the optical cross-connect switch.

12. The method of claim 11 wherein

the converting of the first optical signal into the electrical signal and the converting of the electrical signal into the second optical signal are performed in an input optical path to the all-optical cross-connect switch.

13. The method of claim 11 wherein

the converting of the first optical signal into the electrical signal and the converting of the electrical signal into the second optical signal are performed in an output optical path from the all-optical cross-connect switch.

14. The method of claim 11 wherein

the converting of the first optical signal into the electrical signal and the converting of the electrical signal into the second optical signal regenerates the first optical signal.

15. The method of claim 11 wherein

the converting of the first optical signal into the electrical signal allows for monitoring of the first optical signal.

16. The method of claim 11 wherein,

the first optical signal has a first wavelength and the second optical signal has a second wavelength differing from the first wavelength.