Optical cross-connect switching system with bridging, test access and redundancy

• US 6,597,826 B1
• Filed: 11/01/2000
• Issued: 07/22/2003
• Est. Priority Date: 11/02/1999
• Status: Expired due to Term

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Xros, Inc. (Nortel Networks Corporation)
• Inventors: Clark, Steven, Ramaswami, Rajiv, Ward, Robert R.
• Primary Examiner(s): Palmer, Phan T. H.
• Application Number:
  US09/704,444
• Time in Patent Office: 993 Days
• Field of Search: 385/17, 385/15-24, 385/88, 385/36
• 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 2011/0015 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 2011/0041 Optical control
• CPC Class Codes: H04Q 2011/0043 Fault tolerance
• CPC Class Codes: H04Q 2011/0049 Crosstalk reduction; Noise; Power budget
• CPC Class Codes: H04Q 2011/005 Arbitration and scheduling
• 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

Abstract

In one embodiment, a scalable cross-connect switching system and its corresponding method perform a bridging operation by splitting the incoming light signal into at least a first bridged light signal and a second bridged light signal. The first bridged light signal has a power level equal to or substantially greater than a power level of the second bridged light signal. The disproportionate power levels provide low-loss bridging. Light signals based on these bridged light signals are routed through multiple switch fabrics which provide redundancy in case of failure by switching within the switch fabric. To detect failures, a test access port is configured for monitoring multiple optical paths.

Claims

1. An input/output (I/O) port module comprising:

a substrate; and

a splitter mounted to the substrate, the splitter to receive an incoming light signal, produce a first bridged light signal and a second bridged light signal as a redundant light signal in order to increase reliability of information transmissions in an optical domain.

2. The I/O port module of claims 1, wherein the substrate is a printed circuit board including a first interface to receive the incoming light signal over an optical fiber link.

3. The I/O port module of claim 2 further comprising an optical switch to select one of the at least two light signals received over the second interface.

4. The I/O port module of claim 3 further comprising an optical-to-electrical converter to convert the one of the at least two light signals from an optical domain to an electrical domain for signal analysis.

5. The I/O port module of claim 4 further comprising an electrical-to-optical converter for injecting a test signal to actively test an optical path through a remotely located switch fabric.

6. The I/O port module of claim 1 further comprising a first tap coupler coupled to the splitter, the first tap coupler to separate the first bridged light signal into a first outgoing light signal and a first optical tap signal for use in monitoring a power level of the first outgoing light signal.

7. The I/O port module of claim 6, wherein the first outgoing light signal and the first optical tap signal produced by the first tap coupler have substantially disproportionate power levels.

8. The I/O port module of claim 6 further comprising a second tap coupler coupled to the splitter, the second tap coupler to separate the second bridged light signal into a second outgoing light signal and a second optical tap signal for use in monitoring a power level of the second outgoing light signal.

9. The I/O port module of claim 1, wherein the first bridged light signal and the second bridged light signal produced by the splitter have substantially equal power levels.

10. The I/O port module of claim 1, wherein the first bridged light signal and the second bridged light signal produced by the splitter have substantially disproportionate power levels.

11. A method comprising:

receiving an incoming light signal having a predetermined power level; and

performing a bridging operation by splitting the incoming light signal into at least a first outgoing light signal routed over a first optical data path and a second outgoing light signal routed over a second optical data path, the second outgoing light signal to monitor for disruption of the first optical data path.

12. The method of claim 11, wherein the first outgoing light signal and the second outgoing light signal have a collective power level substantially equal to the predetermined power level.

13. The method of claim 12, wherein the collective power level of the first outgoing light signal and the second outgoing light signal is equal to the predetermined power level minus a power loss caused by the splitting of the incoming light signal.

14. The method of claim 11, wherein the first outgoing light signal having a power level substantially greater than a power level of the second outgoing light signal.

15. The method of claim 14 further comprising:

providing the second outgoing light signal to a multiple input optical switch; and

selecting outputting a signal input into the multiple input optical switch for analysis by an optical-to-electrical conversion and monitoring device.

16. The method of claim 15 further comprising:

selecting the second outgoing light signal for output from an optical switch of a destination I/O port module when the first optical path is disrupted.