Optical layer survivability and security system using optical label switching and high-speed optical header generation and detection

• US 6,271,946 B1
• Filed: 12/29/1999
• Issued: 08/07/2001
• Est. Priority Date: 01/25/1999
• Status: Expired due to Term

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Telcordia Technologies Incorporated (Telefonaktiebolaget LM Ericsson)
• Inventors: Chang, Gee-Kung, Ellinas, Georgios, Graveman, Richard, Monma, Clyde
• Primary Examiner(s): NEGASH, KINFE MICHAEL
• Application Number:
  US09/473,432
• Time in Patent Office: 587 Days
• Field of Search: 359/123-125, 359/135, 359/128, 370/352, 370/392, 370/471, 370/355-356
• US Class Current: 398/79
• 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 14/0278 WDM optical network architectures
• CPC Class Codes: H04J 14/0283 WDM ring architectures
• CPC Class Codes: H04J 14/0284 WDM mesh architectures
• CPC Class Codes: H04J 14/0293 Optical channel protection
• CPC Class Codes: H04J 14/0294 Dedicated protection at the optical channel (1+1)
• CPC Class Codes: H04J 14/0295 Shared protection at the optical channel (1:1, n:m)
• CPC Class Codes: H04J 14/0298 with sub-carrier multiplexing [SCM]
• CPC Class Codes: H04Q 11/0062 Network aspects
• CPC Class Codes: H04Q 2011/0016 using wavelength multiplexing or demultiplexing
• 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 2011/0088 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 header and data payload propagate through network elements with the same path and the associated delays. The technique effects survivability and security of the optical networks by encompassing conventional electronic security with an optical security layer by generating replicated versions of the input data payload at the input node, and the transmission of each of the replicated versions over a corresponding one of the plurality of links. Moreover, each of the links is composed of multiple wavelengths to propagate optical signals or optical packets, and each of the replicated versions of the data payload may be propagated over a selected one of the wavelengths in each corresponding one of the plurality of links.

Claims

1. A method for propagating an input 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 each including a switch, the input 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,

generating and storing replicated versions of the input data payload in the input network element,

adding an optical header to each of the replicated versions of the input data payload to produce a plurality of corresponding optical signals, the header having a format and protocol and being indicative of the local route through each of the network elements for each of the optical signals, the format and protocol of the data payload being independent of the format and protocol of the header,

optically transmitting each of the optical signals over a corresponding one of the links,

detecting the header of each of the optical signals at the network elements to produce a corresponding switch control signal as each of the optical signals propagates through the WDM network,

selecting one of the local routes for routing each of the optical signals through each of the network elements by looking up the switch control signal in the corresponding local routing table to operate the corresponding switch, and

routing each of the optical signals to the output network element through the network elements in correspondence to the selected route,

wherein each header is composed of one or more header signals each being conveyed by a distinct sub-carrier frequency and arranged so that the highest detectable sub-carrier frequency corresponds to an active header signal, the plurality of sub-carrier frequencies occupying a frequency band above the input data payload, the step of detecting including the steps of

concurrently measuring the header signals to produce a header selection signal,

selecting the active header signal as conveyed by the highest detectable sub-carrier frequency under control of the header selection signal, and

processing the active header signal to obtain the switch control signal for routing the optical signal.

2. The method as recited in claim 1 wherein the optical header includes a label-switch state for routing the corresponding optical signal through the network elements, and the step of adding an optical header includes the steps of determining and inserting in the optical header an appropriate label-switch state for routing the corresponding optical signal from the input network element to the output network element through the network elements.

6. The method as recited in claim 1 wherein the step of adding the optical header includes the step of assigning the local route for each of the optical signals through the network based upon a time-dependent assignment algorithm.

7. The method as recited in claim 6 wherein the time-dependent assignment algorithm is based upon generating secure pseudo-random numbers.

8. The method as recited in claim 6 wherein the step of adding the header includes the step of adding information to the header representative of the time-dependent assignment algorithm.

3. The method as recited in 1 wherein each of the links includes multiple optical wavelengths and wherein the step of optically transmitting includes the step of propagating each of the optical signals over a selected one of the wavelengths composing said one of the corresponding links.

4. The method as recited in claim 3 wherein the step of generating includes the step of electronically replicating the data payload.

5. The method as recited in claim 4 wherein the step of storing includes the step of storing each electronically replicated data payload.

9. A method for propagating a sequence of related data payloads from an input network element to an output network element over a wavelength division multiplexing (WDM) network composed of a plurality of network elements and links interconnecting the network elements, each of the related data payloads 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,

generating and storing replicated versions of each of the related data payloads in the input network element,

adding an optical header to each of the replicated versions of the related data payloads to produce a plurality of corresponding optical signals, the header having a format and protocol and being indicative of the local route through each of the network elements for each of the optical signals, the format and protocol of each of the replicated versions of each of the related data payloads being independent of the format and protocol of the header,

optically transmitting each of the optical signals over a corresponding one of the links,

detecting the header of each of the optical signals at the network elements to produce a corresponding switch control signal as each of the optical signals propagates through the WDM network,

selecting one of the local routes for routing each of the optical signals through each of the network elements by looking up the switch control signal in the corresponding local routing table to operate the corresponding switch, and

routing each of the optical signals to the output network element through the network elements in correspondence to the selected route,

wherein each header is composed of one or more header signals each being conveyed by a distinct sub-carrier frequency and arranged so that the highest detectable sub-carrier frequency corresponds to an active header signal, the plurality of sub-carrier frequencies occupying a frequency band above the input data payload, the step of detecting including the steps of

concurrently measuring the header signals to produce a header selection signal,

selecting the active header signal as conveyed by the highest detectable sub-carrier frequency under control of the header selection signal, and

processing the active header signal to obtain the switch control signal for routing the optical signal.

10. The method as recited in claim 9 wherein the optical header includes a label-switch state for routing the corresponding optical signal through the network elements, and the step of adding an optical header includes the steps of determining and inserting in the optical header an appropriate label-switch state for routing the corresponding optical signal from the input network element to the output network element through the network elements.

11. The method as recited in claim 9 wherein each of the links includes multiple optical wavelengths and wherein the step of optically transmitting includes the step of propagating each of the optical signals over a selected one of the wavelengths composing said one of the corresponding links.

12. The method as recited in claim 11 wherein the step of generating includes the step of electronically replicating each of the related data payloads.

13. The method as recited in claim 12 wherein the step of storing includes the step of storing each electronically replicated one of the related data payloads.

14. The method as recited in claim 9 wherein the step of adding the optical header includes the step of assigning the local route for each the optical signals through the network based upon a time-dependent assignment algorithm.

15. The method as recited in claim 9 wherein the step of generating includes the steps of grouping a plurality of incoming data payloads to produce the related data payloads and partitioning the related data payloads into disjoint subsets, and the step of storing further includes the step of storing the disjoint subsets.

16. The method as recited in claim 15 wherein each of the links includes multiple optical wavelengths and wherein the step of optically transmitting includes the step of propagating each of the subsets over a selected one of the wavelengths composing said one of the corresponding links.

17. The method as recited in claim 16 wherein the step of optically transmitting over one of the corresponding links includes the step of assigning said selected one of the wavelengths based upon a time-dependent assignment algorithm.

18. The method as recited in claim 17 wherein the time-dependent assignment algorithm is based upon generating secure pseudo-random numbers.

19. A method for propagating a data payload arriving at an input network element onto a wavelength division multiplexing (WDM) network composed of a plurality of network elements interconnected by links, the data payload having a given format and protocol, the method comprising the steps of

generating and storing replicated versions of the data payload in the input network element,

generating a header associated with each replicated data payload, the header having a format and protocol and being indicative of a local route through each of the network elements for the header and its associated data payload, the format and protocol of the data payload being independent of the format and protocol of the header,

optically adding the header to its associated data payload to produce a plurality of corresponding optical signals, and optically transmitting each of the optical signals over a corresponding one of the links,

wherein the step of generating each header includes the steps of

generating a header signal at baseband with a pre-determined frequency spectrum, the header signal being representative of the header,

frequency-shifting the header signal using a carrier frequency so that the frequency-shifted spectrum of the header signal is located above the frequency spectrum of the data payload,

adding the frequency-shifted header signal and the data payload to produce a combined signal, and

electro-optically converting the combined signal to generate the corresponding one of the optical signals.

20. The method as recited in claim 19 wherein the header includes a label-switch state for routing the corresponding optical signal through the network elements, and the step of adding a header includes the steps of determining and inserting in the header an appropriate label-switch state for routing the corresponding optical signal.

24. The method as recited in claim 19 wherein the step of optically adding the header includes the step of assigning the local route for each the optical signals through the network based upon a time-dependent assignment algorithm.

25. The method as recited in claim 24 wherein the time-dependent assignment algorithm is based upon generating secure pseudo-random numbers.

21. The method as recited in 19 wherein each of the links includes multiple optical wavelengths and wherein the step of optically transmitting includes the step of propagating each of the optical signals over a selected one of the wavelengths composing said one of the corresponding links.

22. The method as recited in claim 21 wherein the step of generating includes the step of electronically replicating the data payload.

23. The method as recited in claim 22 wherein the step of storing includes the step of storing each electronically replicated data payload.

26. A system for propagating an input 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 interconnected by links, 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,

a data generator for generating and storing replicated versions of the input data payload in the input network element,

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

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

a selector for selecting one of the local routes for routing the optical 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 each header is composed of one or more header signals each being conveyed by a distinct sub-carrier frequency and arranged so that the highest detectable sub-carrier frequency corresponds to an active header signal, the plurality of sub-carrier frequencies occupying a frequency band above the data payload, the detector further comprising

a measurement device for concurrently measuring the header signals to produce a header selection signal,

a selector, coupled to the measurement device, for determining the active header signal as conveyed by the highest detectable sub-carrier frequency under control of the header selection signal, and

a processor, coupled to the selector, for processing the active header signal to produce the switch control signal to control the switch.