High-throughput, low-latency next generation internet networks using optical label switching and high-speed optical header generation, detection and reinsertion

• US 20010017723A1
• Filed: 01/05/2001
• Published: 08/30/2001
• Est. Priority Date: 07/17/1998
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Chang, Gee-Kung, Way, Winston I.
• Granted Patent: US 6,525,851 B2
• Time in Patent Office: Days
• US Class Current: 398/82
• CPC Class Codes: H04J 14/0227 Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
• CPC Class Codes: H04J 14/0241 Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths
• CPC Class Codes: H04J 14/0284 WDM mesh architectures
• CPC Class Codes: H04J 14/0298 with sub-carrier multiplexing [SCM]
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/168 specially adapted for link layer protocols, e.g. asynchronous transfer mode [ATM], synchronous optical network [SONET] or point-to-point protocol [PPP]
• 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 2011/0039 Electrical control
• CPC Class Codes: H04Q 2011/0041 Optical control
• CPC Class Codes: H04Q 2011/0073 Provisions for forwarding or routing, e.g. lookup tables
• CPC Class Codes: H04Q 2011/0077 Labelling aspects, e.g. multiprotocol label switching [MPLS], G-MPLS, MPAS
• CPC Class Codes: H04Q 2011/0088 Signalling aspects

Abstract

An optical signaling header technique applicable to optical networks wherein packet routing information is embedded in the same channel or wavelength as the data payload so that both the single-sideband modulated header and data payload propagate through network elements with the same path and the associated delays. The header routing information has sufficiently different characteristics from the data payload so that the signaling header can be detected without being affected by the data payload, and that the signaling header can also be removed without affecting the data payload. The signal routing technique can overlaid onto the conventional network elements in a modular manner using two types of applique modules. The first type effects header encoding and decoding at the entry and exit points of the data payload into and out of the network; the second type effects header detection at each of the network elements.

Claims

1. A method for propagating a data payload from an input network element to an output network element in a wavelength division multiplexing (WDM) network composed of a plurality of network elements, the data payload having a given format and protocol, the method comprising the steps of

generating and storing a local routing look-up table in each of the network elements, each local routing table determining alternative local routes through the associated one of the network elements,

adding a header to the data payload prior to inputting the data payload to the input network element to produce an optical signal, the header having a format and protocol and being indicative of a local route through each of the network elements for the data payload and the header, the format and protocol of the data payload being independent of the format and protocol of the header,

detecting the header at the network elements to produce a switch control signal as the data payload and header propagate through the WDM network,

selecting one of the local routes for routing the optical signal through the network elements as determined by looking up the switch control signal in the corresponding local routing table, and

routing the optical signal through the network elements in correspondence to the selected route,

wherein the header is conveyed by a single sideband signal occupying a given frequency band above the data payload,

the step of detecting including the steps of

opto-electrically converting the optical signal to detect the header, and

processing the header to produce a switch control signal to route the incoming optical signal,

the method further comprising, prior to the step of routing, the steps of

optically filtering the optical signal with a reflective part of a notch filter to delete the header and recover the data payload, and

inserting a new single-sideband header at the given frequency band into the optical signal in place of the deleted header.

2. The method as recited in

claim 1

wherein the step of processing further includes the step of demodulating the detected header to produce header information.

3. The method as recited in

claim 2

wherein the step of processing further includes the step of reading the header information to produce the switch control signal.

4. The method as recited in

claim 1

wherein the step of processing further includes the steps of

demodulating the detected header to produce header information, and

reading the header information to produce the switch control signal.

5. The method as recited in

claim 1

wherein the notch filter is a Fabry-Perot filter having a free-spectral range centered on the given frequency band .

6. The method as recited in

claim 5

wherein the step of processing further includes the step of demodulating the detected header to produce header information.

7. The method as recited in

claim 6

wherein the step of processing further includes the step of reading the header information to produce the switch control signal.

8. The method as recited in

claim 1

wherein the step of processing further includes the steps of

generating an intermediate frequency (IF) electrical signal from the detected header,

demodulating the IF electrical signal to produce a demodulated signal,

detecting the demodulated signal to produce header information, and

reading the header information to produce the switch control signal.

9. The method as recited in

claim 1

wherein the step of inserting includes the step of single-sideband modulating the new header with a carrier in the given frequency band.

10. The method as recited in

claim 1

wherein the step of inserting includes the step of single-sideband modulating the new header and the data payload with a Mach-Zender modulator.

11. The method as recited in

claim 1

further including an add-drop optical switch controlled by the switch control signal and wherein the step of inserting further includes the step of supplying the single-sideband modulated new header and the data payload to the add-drop optical switch.

12. The method as recited in

claim 1

wherein the step of inserting the new header includes the step of referencing the local routing table for routes through the optical switch.

13. A method for replacing a header and for routing an optical signal propagating at a given optical wavelength, the optical signal including both the header and a data payload, the header being conveyed by a single-sideband signal occupying a given frequency band above the data payload, the method comprising the steps of

opto-electrically converting the optical signal to detect the header,

processing the header to produce a switch control signal to route the optical signal,

optically filtering the optical signal with a reflective part of the notch filter to delete the header and recover the data payload, and

inserting a new single-sideband header at the given frequency band into the optical signal in place of the deleted header.

14. The method as recited in

claim 13

wherein the step of processing further includes the step of demodulating the detected header to produce header information.

15. The method as recited in

claim 14

wherein the step of processing further includes the step of reading the header information to produce the switch control signal.

16. The method as recited in

claim 13

wherein the step of processing further includes the steps of

demodulating the detected header to produce header information, and

reading the header information to produce the switch control signal.

17. The method as recited in

claim 13

wherein the notch filter is a Fabry-Perot filter having a free-spectral range centered on the given frequency band.

18. The method as recited in

claim 17

wherein the step of processing further includes the step of demodulating the detected header to produce header information.

19. The method as recited in

claim 18

wherein the step of processing further includes the step of reading the header information to produce the switch control signal.

20. The method as recited in

claim 13

wherein the step of processing further includes the steps of

generating an intermediate frequency (IF) electrical signal from the detected header,

demodulating the IF electrical signal to produce a demodulated signal,

detecting the demodulated signal to produce header information, and

reading the header information to produce the switch control signal.

21. The method as recited in

claim 13

wherein the step of inserting includes the step of single-sideband modulating the new header with a carrier in the given frequency band.

22. The method as recited in

claim 13

wherein the step of inserting includes the step of single-sideband modulating the new header and the data payload with a Mach-Zender modulator.

23. The method as recited in

claim 22

further including an add-drop optical switch controlled by the switch control signal and wherein the step of inserting further includes the step of supplying the single-sideband modulated new header and data payload to the add-drop optical switch.

24. The method as recited in

claim 23

wherein the step of inserting the new header includes the step of referencing a local routing table for routes through the optical switch.

25. A method for replacing a header and for routing an optical signal propagating at a given optical wavelength, the optical signal including both the header and a data payload, the header being conveyed by a single-sideband signal occupying a given frequency band above the data payload, the method comprising the steps of

opto-electrically converting the header to produce header information,

reading the header information to produce a switch control signal to route the optical signal,

optically filtering the optical signal with a reflective part of the notch filter to delete the header and recover the data payload, and

inserting a new single-sideband header at the given frequency band into the optical signal in place of the deleted header with a Mach-Zender modulator.

26. A system for replacing a header and for routing an optical signal propagating at a given optical wavelength, the optical signal including both the header and a data payload, the header being conveyed by a single-sideband signal occupying a given frequency band above the data payload, the system comprising

an opto-electrical converter for converting the optical header to a detected header,

a processor, coupled to opto-electrical converter, for processing the header to produce a switch control signal to route the optical signal,

an optical notch filter for filtering the optical signal with a reflective part of the notch filter to delete the header and recover the data payload, and

means, coupled to the notch filter, for inserting a new single-sideband header at the given frequency band into the optical signal in place of the deleted header.

27. The system as recited in

claim 26

wherein the processor further includes a demodulator for demodulating the detected header to produce header information.

28. The system as recited in

claim 27

wherein the processor further includes a reader for reading the header information to produce the switch control signal.

29. The system as recited in

claim 26

wherein the processor further includes

a generator for generating an intermediate frequency (IF) electrical signal from detected header,

a demodulator for demodulating the IF electrical signal to produce a demodulated signal,

a detector for detecting the demodulated signal to produce header information, and

a reader for reading the header information to produce the switch control signal.

30. The system as recited in

claim 26

wherein the notch filter is a Fabry-Perot filter having a free-spectral range centered on the given frequency band.

31. The system as recited in

claim 30

wherein the processor further includes a demodulator for demodulating the detected header to produce header information.

32. The system as recited in

claim 31

wherein the processor further includes a reader for reading the header information to produce the switch control signal.

33. The system as recited in

claim 30

wherein the processor further includes

a generator for generating an intermediate frequency (IF) electrical signal from the detected header,

a demodulator for demodulating the IF electrical signal to produce a demodulated signal,

a detector for detecting the demodulated signal to produce header information, and

a reader for reading the header information to produce the switch control signal.

34. The system as recited in

claim 26

wherein means for inserting includes a single-sideband modulator for modulating the new header with a carrier in the given frequency band.

35. The system as recited in

claim 26

wherein the means for inserting includes a Mach-Zender single-sideband modulator for modulating the new header and the data payload.

36. A system for propagating a data payload from an input network element to an output network element in a wavelength division multiplexing (WDM) network composed of a plurality of network elements, the data payload having a given format and protocol, the system comprising

a route generator for generating and storing a local routing look-up table in each of the network elements, each local routing table determining alternative local routes through the associated one of the network elements,

an adder for adding a header to the data payload prior to inputting the data payload to the input network element to produce an optical signal, the header having a format and protocol and being indicative of a local route through each of the network elements for the data payload and the header, the format and protocol of the data payload being independent of the format and protocol of the header,

a detector for detecting the header at the network elements to produce a switch control signal as the data payload and header propagate through the WDM network,

a router for selecting one of the local routes for routing the optical signal through the network elements as determined by looking up the switch control signal in the corresponding local routing table, and

a switch for routing the optical signal through the network elements in correspondence to the selected route,

wherein the header is conveyed by a single-sideband signal occupying a given frequency band above the data payload,

the detector further comprising

an opto-electrical converter for converting the optical signal to detect the header, and

a processor, coupled to opto-electrical converter, for processing the header to produce a switch control signal to route the optical signal,

the system further comprising

an optical notch filter for filtering the optical signal with a reflective part of the notch filter to delete the header and recover the data payload, and

means, coupled to the notch filter, for inserting a new single-sideband header at the given frequency band into the optical signal in place of the deleted header.