Hybrid electronic/optical switch system

• US 6,647,208 B1
• Filed: 08/18/1999
• Issued: 11/11/2003
• Est. Priority Date: 03/18/1999
• Status: Expired due to Fees

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Kirby, Alan J.
• Primary Examiner(s): MULLEN, THOMAS J
• Application Number:
  US09/376,504
• Time in Patent Office: 1,546 Days
• Field of Search: 359/110, 359/117, 359/124, 359/128, 359/139, 359/326, 385/16, 385/17, 398/9, 398/43, 398/45, 398/46, 398/58, 398/79, 398/82
• US Class Current: 398/45
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 11/0066 Provisions for optical burst or packet networks
• CPC Class Codes: H04Q 11/0071 Provisions for the electrical-optical layer interface
• CPC Class Codes: H04Q 2011/0016 using wavelength multiplexing or demultiplexing
• CPC Class Codes: H04Q 2011/002 using optical delay lines or optical buffers or optical recirculation
• CPC Class Codes: H04Q 2011/0024 using space switching
• CPC Class Codes: H04Q 2011/0039 Electrical control
• CPC Class Codes: H04Q 2011/0049 Crosstalk reduction; Noise; Power budget
• CPC Class Codes: H04Q 2011/0052 Interconnection of switches
• CPC Class Codes: H04Q 2011/0069 using dedicated optical channels
• CPC Class Codes: H04Q 2011/0077 Labelling aspects, e.g. multiprotocol label switching [MPLS], G-MPLS, MPAS
• CPC Class Codes: H04Q 2011/0086 Network resource allocation, dimensioning or optimisation

Abstract

A high speed optical communication and data transfer network comprises fiber optic links interconnecting a plurality of hybrid electronic-optical switch devices, each hybrid switch circuit including an electronic switch, electronic switch controller and optical switch. The hybrid switch circuits and nodes on the periphery of the core network communicate amongst each other over a first dedicated wavelength. Optical signals on the first dedicated wavelength are converted to electronic signals which are monitored by the electronic controller in each hybrid switch circuit. Routing in the network is optimized by transmitting lower volume data traffic on the first dedicated wavelength which is typically slower due to optical/electronic signal conversions and which uses more resources. Higher capacity data transfers are achieved by transmitting data on an assigned carrier wavelength over an established flow path among the optical switches of multiple hybrid switch circuits. Based on high and low volume data traffic, the method and apparatus discussed herein advantageously supports direct and indirect optical data transmissions with as few overall intermediate optical-to-electrical or electrical-to-optical conversions as possible.

Claims

1. A hybrid switch circuit comprising:

an optical switch including fiber inputs and fiber outputs for routing optical data signals from an input fiber to an output fiber;

an electronic switch including an electronic controller for converting and monitoring traffic on at least a first dedicated wavelength used for communications and data transmissions among multiple hybrid switch circuits, wherein the electronic controller communicates with upstream and downstream circuits to establish a flow path for routing wavelengths on input fibers to output fibers in the optical switch; and

at least one feedback circuit for feeding an optical output of the optical switch to an optical input.

2. A hybrid switch circuit as in claim 1 wherein the upstream and downstream circuits include other switch circuits.

3. A hybrid switch circuit as in claim 1 wherein the upstream and downstream circuits include other hybrid switch circuits.

4. A hybrid switch circuit as in claim 1 wherein the electronic controller converts optical data signals at the first dedicated wavelength to electronic signals and re-transmits at least part of the received optical data signals on the first dedicated wavelength to other hybrid switch circuits.

5. A hybrid switch circuit as in claim 4 wherein the electronic controller additionally creates and transmits messages to other hybrid switch circuits and peripheral nodes in a core network over the first dedicated wavelength.

6. A hybrid switch circuit as in claim 1 wherein at least some of the data transmitted among hybrid switch circuits includes tags indicating virtual circuits and the hybrid switch circuits monitor traffic on individual virtual circuits to initiate flow paths.

7. A hybrid switch circuit as in claim 1 wherein the electronic controller monitors traffic on a plurality of dedicated wavelengths to establish flow paths for optical routing of signals.

8. A hybrid switch circuit as in claim 1 wherein communication among hybrid switch circuits is based on an MPLS protocol.

9. A hybrid switch circuit as in claim 1 further comprising an electrical link supporting communication among interconnected hybrid switch circuits.

10. A hybrid switch circuit as in claim 1 wherein the electronic controller includes at least one high speed microprocessor.

11. A hybrid switch circuit as in claim 1 wherein the optical switch in a hybrid switch circuit includes a network of optical multiplexors and de-multiplexors controlled by electrical signals for routing an optical signal at a given wavelength.

12. A hybrid switch circuit as in claim 1 wherein a hybrid switch circuit includes a splitter for enabling a simultaneous flow of an optical data signal to more than one output fiber.

13. A hybrid switch as in claim 12 wherein selected output signals from the optical switch are fed into an optical splitter, outputs of which are further routed through the optical switch enabling a simultaneous flow of an optical data signal to more than one destination.

14. A hybrid switch circuit as in claim 1 wherein the hybrid switch circuits support bi-directional data flow on optical fibers interconnecting the hybrid switch circuits.

15. A hybrid switch circuit as in claim 1 wherein a flow path is established depending on a level of multi-protocol label switching traffic through the hybrid switch circuit.

16. A hybrid switch circuit as in claim 1 further comprising:

a regenerator for regenerating the optical data signals, the regenerator disposed in a feedback path between an output and input fiber of the hybrid switch circuit.

17. A hybrid switch circuit as in claim 1 further comprising:

a wavelength converter for converting a selected optical data signal to a different wavelength, wherein the wavelength converter is disposed in a feedback path between an output and input fiber of the hybrid switch circuit.

18. A hybrid switch circuit as in claim 1 further comprising:

at least one feedback path from an output fiber of the optical switch to an input of the electronic switch.

19. A hybrid switch circuit as in claim 1 wherein the optical switch is occasionally tested to assure reliability of routing optical data signals from an input fiber to an output fiber.

20. A hybrid switch circuit as in claim 1 wherein at least one flow path is reserved for future use based on historical usage.

21. A hybrid switch circuit as in claim 1 wherein selected flow paths are reserved based on expected usage.

22. A method of supporting communication with a hybrid switch circuit comprising the steps of:

converting and monitoring traffic on a first dedicated wavelength with an electronic controller in the hybrid switch circuit where data is routed through an electronic switch, the first dedicated wavelength supporting data transmissions among multiple hybrid switch circuits;

conmmunicating with upstream and downstream circuits to establish a flow path for routing wavelengths on input fibers to output fibers in an optical switch of the hybrid switch circuit;

routing optical data signals through the optical switch from an input fiber to an output fiber; and

feeding at least one optical output of the optical switch to an optical input.

23. A method as in claim 22 wherein the upstream and downstream circuits include other switch circuits.

24. A method as in claim 22 wherein the upstream and downstream circuits include other hybrid switch circuits.

25. A method as in claim 22 wherein the electronic controller converts optical data signals at the first dedicated wavelength to electronic signals and re-transmits at least part of the received optical data signals on the first dedicated wavelength to other hybrid switch circuits.

26. A method as in claim 25 wherein the electronic controller in a hybrid switch circuit additionally creates and transmits messages to other hybrid switch circuits and peripheral nodes in a core network over the first dedicated wavelength.

27. A method as in claim 22 wherein at least some of the data transmitted among hybrid switch circuits includes tags indicating virtual circuits and the hybrid switch circuits monitor traffic on individual virtual circuits to initiate flow paths.

28. A method as in claim 22 wherein the electronic controller monitors traffic on a plurality of dedicated wavelengths to establish flow paths for optical routing of signals.

29. A method as in claim 22 wherein communication among hybrid switch circuits includes an MPLS protocol.

30. A method as in claim 22 further comprising an electrical link supporting communication among interconnected hybrid switch circuits.

31. A method as in claim 22 wherein the electronic controller includes at least one high speed microprocessor.

32. A method as in claim 22 wherein the optical switch in a hybrid switch circuit includes a network of optical multiplexors and de-multiplexors controlled by electrical signals for routing an optical signal at a given wavelength.

33. A method as in claim 22 wherein a hybrid switch circuit includes a splitter for enabling a simultaneous flow of an optical data signal to more than one output fiber.

34. A method as in claim 33 wherein selected output signals from the optical switch are fed into an optical splitter, outputs of which are further routed through the optical switch enabling a simultaneous flow of an optical data signal to more than one destination.

35. A method as in claim 22 wherein the hybrid switch circuits support bi-directional data flow on optical fibers interconnecting the hybrid switch circuits.

36. A method of communicating with a hybrid switch circuit as in claim 22 further comprising the step of:

establishing a flow path depending on a level of Multi-Protocol Label Switching traffic through the hybrid switch circuit.

37. A method of communicating with a hybrid switch circuit as in claim 22 further comprising the step of:

regenerating the optical data signals in a feedback path between an output and input fiber of the hybrid switch circuit.

38. A method of communicating with a hybrid switch circuit as in claim 22 further comprising the step of:

converting an optical data signal to a different wavelength.

39. A method of communicating with a hybrid switch circuit as in claim 22 further comprising the step of:

feeding back a signal from an output fiber of the optical switch to an input of the electronic controller of the hybrid switch.

40. A method of communicating with a hybrid switch circuit as in claim 22 further comprising the step of:

occasionally testing a flow path by routing an optical data signal from a selected input fiber to an output fiber.

41. A method of communicating with a hybrid switch circuit as in claim 22 further comprising the step of:

reserving at least one flow path for future use based on historical usage.

42. A method of communicating with a hybrid switch circuit as in claim 22 further comprising the step of:

reserving a selected flow path based on expected usage.