Method and apparatus for emulating the optical behavior of optical communication systems

• US 6,807,523 B1
• Filed: 10/31/2001
• Issued: 10/19/2004
• Est. Priority Date: 10/31/2001
• Status: Expired due to Term

• Current Assignee: Ciena Corporation
• Original Assignee: Ciena Corporation
• Inventors: Gaskin, James C., Peters-Rodbell, Michael B., Wensink, James B.
• Primary Examiner(s): PHAN, THAI Q
• Application Number:
  US10/003,074
• Time in Patent Office: 1,084 Days
• Field of Search: 703/14, 703/22, 703/23, 703/24, 703/27, 703/16, 709/223, 709/224, 359/110, 359/118, 359/124, 359/130, 370/386, 370/404
• US Class Current: 703/27
• CPC Class Codes: H04J 14/0201 Add-and-drop multiplexing
• 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 14/0279 WDM point-to-point architectures
• CPC Class Codes: H04J 14/028 WDM bus architectures
• CPC Class Codes: H04J 2014/0253 Allocation of downstream wavelengths for upstream transmission
• CPC Class Codes: H04L 41/145 involving simulating, designing, planning or modelling of a network
• CPC Class Codes: H04Q 2011/0083 Testing; Monitoring
• CPC Class Codes: H04Q 2011/0086 Network resource allocation, dimensioning or optimisation

Abstract

A method and system for emulating the optical behavior of an optical communications generates wavelength modeled objects for each emulated optical signal and a variety of other modeled objects for the optical communications modules of the emulated system such as transmitter modeled objects, a combiner modeled object, an amplifier modeled object, a splitter modeled object, and receiver modeled objects. Each of the modeled objects includes certain optical attributes and a behavior modeling function particular to the module being emulated. The optical modules themselves are also represented as emulated processes. The modeled objects are propagated along a logical path from emulated process to emulated process. Upon receipt of a modeled object the emulated process executes the behavior modeling function and updates modeling objects affected by the execution. The propagation of modeled objects and execution of behavior modeling functions in this fashion results in a cascade of optical property changes across the emulated system.

Claims

1. A method of emulating the optical behavior of an optical communications system having a plurality of optical communications modules, comprising:

generating a wavelength modeled object modeling at least a signal condition of an optical signal;

generating a modeled object for each of the optical communications modules and including at least an optical power level field and a behavior modeling function modeling the optical behavior of the corresponding optical communications module;

propagating the wavelength modeled object along a logical path of emulated optical communications modules;

executing the behavior modeling function of the modeled object associated with the emulated optical communications module receiving the propagated wavelength modeled object; and

storing the results of said executing in the associated modeled object.

2. The method of emulating the optical behavior of an optical communications system according to claim 1,

wherein the optical communications system includes a plurality of nodes;

wherein the modeled objects are organized into a plurality of nodes emulating the nodes of the optical communications system;

said propagating step propagating a span modeled object between nodes, the span modeled object including the propagated wavelength modeled object.

3. The method of emulating the optical behavior of an optical communications system according to claim 1,

wherein the optical communications system includes a plurality of spans, each span having a plurality of nodes;

wherein the modeled objects are organized into a plurality of spans and nodes emulating the spans and nodes of the optical communications system;

said propagating step propagating a multi-span modeled object between spans, the multi-span modeled object including the propagated wavelength modeled object.

4. The method of emulating the optical behavior of an optical communications system according to claim 1, wherein the optical communications system being emulated is a wavelength division multiplexed system transmitting a plurality of optical signals at respective wavelengths, the method further comprising:

generating a plurality of wavelength modeled objects modeling at least the signal conditions and wavelengths of the optical signals; and

propagating the wavelength modeled objects along a logical path of emulated optical communications modules.

5. The method of emulating the optical behavior of an optical communications system according to claim 4, wherein the optical communications system being emulated includes an optical combiner combining at least some of the plurality of optical signals, the method further comprising:

generating a combiner modeled object including an output signal power level field, the plurality of propagated wavelength modeled objects, and a combiner behavior modeling function modeling the optical behavior of an optical wavelength combiner;

executing the combiner behavior modeling function and storing the results thereof in the combiner modeled object; and

propagating the combiner modeled object to a next emulated optical communications module along the logical path of emulated optical communications modules.

6. The method of emulating the optical behavior of an optical communications system according to claim 4, wherein the wavelength modeled objects further include a data rate field.

7. The method of emulating the optical behavior of an optical communications system according to claim 4, wherein the wavelength modeled objects further include an error count field.

8. The method of emulating the optical behavior of an optical communications system according to claim 4, wherein the signal conditions of the wavelength modeled objects include Loss Of Signal, Loss Of Framing, Loss Of Modulation, and Signal OK fields.

9. The method of emulating the optical behavior of an optical communications system according to claim 4, wherein the optical communications system includes a optical amplifier, the method further comprising:

generating an amplifier modeled object including an output signal power level field, an input power level field, pump power level field, the plurality of propagated wavelength modeled objects, and an amplifier behavior modeling function modeling the optical behavior of the optical amplifier;

executing the amplifier behavior modeling function and storing the results thereof in the amplifier modeled object.

10. The method of emulating the optical behavior of an optical communications system according to claim 9,

said executing the amplifier behavior modeling function including overriding the signal conditions in the propagated wavelength modeled objects to Loss Of Signal if the value of the input power level field is less than a first threshold value or if the value of pump power level field is less than a second threshold value.

11. The method of emulating the optical behavior of an optical communications system according to claim 9,

said executing the amplifier behavior modeling function including overriding the signal conditions in the propagated wavelength modeled objects to loss of frame if more than one transmitter modeled object has the same wavelength value.

12. The method of emulating the optical behavior of an optical communications system according to claim 4, wherein the optical communications system being emulated includes a splitter and a plurality of optical receivers, the method further comprising:

generating a splitter modeled object including an output signal power level field, the plurality of propagated wavelength modeled objects, and a splitter behavior modeling function modeling the optical behavior of an optical splitter;

generating a plurality of receiver modeled objects including an input signal power level field, a wavelength field, a signal condition field, one of the plurality of propagated wavelength modeled objects, and a receiver behavior modeling function modeling the optical behavior of an optical receiver;

executing the receiver behavior modeling function and storing the results thereof in the receiver modeled object.

13. The method of emulating the optical behavior of an optical communications system according to claim 12,

wherein the wavelength modeled objects further include a data rate field,

said executing the receiver behavior modeling function including overriding the signal condition in the receiver modeled object to loss of frame based on a determination of whether the data rate field of the propagated wavelength modeled object matches the data rate field of the receiver modeled object.

14. The method of emulating the optical behavior of an optical communications system according to claim 12,

said executing the receiver behavior modeling function including overriding the signal condition to Loss Of Signal in the receiver modeled object based on a determination of whether the signal condition field of the propagated wavelength modeled object indicates a signal unknown condition.

15. The method of emulating the optical behavior of an optical communications system according to claim 12,

said executing the receiver behavior modeling function including setting the input signal power level in the receiver modeled object to zero if the signal condition field of the propagated wavelength modeled object indicates a loss of signal condition.

16. The method of emulating the optical behavior of an optical communications system according to claim 1,

wherein the next emulated optical communications module along the logical path is a optical backplane emulator and said execution step is performed by the optical backplane emulator, the method further comprising:

maintaining optical attributes at each of the emulated optical communications modules;

updating at least one of the optical attributes when said executing step results in a change to a corresponding optical attribute field in the modeled object associated with said executing step.

17. The method of emulating the optical behavior of an optical communications system according to claim 1,

wherein said execution step is performed by the emulated optical communications modules.

18. The method of emulating the optical behavior of an optical communications system according to claim 1, further comprising:

parsing an interconnect configuration file storing configurations of and logical interconnections between the emulated optical communications modules,

said generating step generating a modeled object for each of the emulated optical communications modules parsed in said parsing step.

19. The method of emulating the optical behavior of an optical communications system according to claim 1, further comprising:

commanding a change in at least one of the modeled objects;

executing the behavior modeling function in the modeled object changed by said commanding step; and

storing the results of said executing in the associated modeled object.

20. A software emulation method for emulating the optical behavior of a system of optical communications elements of an optical communications system wherein the system includes hardware node elements and at least some of the hardware node elements include a nodal control processor and a bus, the method comprising:

maintaining modeled objects for each of the optical communications elements being emulated wherein each of the modeled objects includes a behavior modeling function modeling the optical behavior of the corresponding optical communications element;

receiving a first behavior event object trigger associated with a first emulated optical communications element;

executing the behavior modeling function of the modeled object associated with the first behavior event object trigger; and

updating the modeled object affected by the execution of the first behavior modeling function.

21. The software emulation method for emulating the optical behavior of a system of optical communications elements according to claim 20, further comprising:

generating the first behavior event object trigger when at least one of the modeled objects has been received by the first emulated optical communications element.

22. The software emulation method for emulating the optical behavior of a system of optical communications elements according to claim 20, further comprising:

maintaining optical attributes of the emulated optical communications elements;

changing at least one of the maintained optical attributes of the emulated optical communications element affected by the execution of the first behavior modeling function; and

sending a second behavior object trigger to the emulated optical communications element associated with the optical attributes changed by said changing step.

23. The software emulation method for emulating the optical behavior of a system of optical communications elements according to claim 20, further comprising:

executing the behavior modeling function of each modeled object affected by the first behavior event object trigger; and

updating the modeled objects affected by the execution of the behavior modeling functions executed by said executing step.