Method and system for assigning modulation format in optical networks

• US 10,461,881 B2
• Filed: 10/08/2018
• Issued: 10/29/2019
• Est. Priority Date: 09/25/2017
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Kim, Inwoong, Wang, Xi, Vassilieva, Olga, Palacharla, Paparao, Ikeuchi, Tadashi
• Primary Examiner(s): Cors, Nathan M
• Application Number:
  US16/154,503
• Publication Number:
  US 20190097747A1
• Time in Patent Office: 386 Days
• CPC Class Codes: H04B 10/0793 Network aspects, e.g. central monitoring of transmission parameters
• CPC Class Codes: H04B 10/07953 Monitoring or measuring OSNR, BER or Q
• CPC Class Codes: H04J 14/0257 Wavelength assignment algorithms
• CPC Class Codes: H04J 14/026 using WDM channels of different transmission rates
• CPC Class Codes: H04J 14/0267 Optical signaling or routing
• CPC Class Codes: H04J 14/0278 WDM optical network architectures

Abstract

Systems and methods for identifying a pair of nodes of a plurality of nodes of a virtual optical network (VON); identifying i) an optical route between the pair of nodes and ii) a desired availability of the optical route; determining a probability density function (PDF) of a signal-to-noise ratio (SNR) of a signal of the optical route; determining a SNR threshold such that an integration of the PDF of the SNR of the signal above the SNR threshold corresponds to the desired availability of the optical route; determining a plurality of spectral efficiencies that corresponds to the SNR threshold, each spectral efficiency of the plurality of spectral efficiencies associated with a respective modulation format of a plurality of modulation formats; and identifying a particular modulation format of the plurality of modulation formats that corresponds to a maximum spectral efficiency of the plurality of spectral efficiencies.

Claims

1. A method for assigning a modulation format in optical networks, the method comprising:

identifying a pair of nodes of a plurality of nodes of a virtual optical network (VON);

identifying an optical route between the pair of nodes;

determining a desired availability of the optical route;

determining a probability density function (PDF) of a signal-to-noise ratio (SNR) of a signal of the optical route;

determining a SNR threshold such that an integration of the PDF of the SNR of the signal above the SNR threshold corresponds to the desired availability of the optical route;

determining a plurality of spectral efficiencies that corresponds to the SNR threshold, each spectral efficiency of the plurality of spectral efficiencies associated with a respective modulation format of a plurality of modulation formats;

identifying a particular modulation format of the plurality of modulation formats that corresponds to a maximum spectral efficiency of the plurality of spectral efficiencies;

assigning the particular modulation format to the virtual optical network; and

transmitting or receiving traffic over the virtual optical network using the particular modulation format.

2. The method of claim 1, wherein identifying the particular modulation format includes identifying parameters of the particular modulation format.

3. The method of claim 2, wherein the parameters include probabilistic shaping (PS) parameters or time-domain hybrid quadrature amplitude modulation (TDHQ) parameters.

4. The method of claim 1, further comprising determining a baud rate based on the maximum spectral efficiency.

5. The method of claim 1, further comprising:

calculating an additional desired availability of the optical route;

determining an additional SNR threshold such than an integration of the PDF of the SNR of the signal above the additional SNR threshold corresponds to the additional desired availability of the optical route;

determining an additional plurality of spectral efficiencies that corresponds to the additional SNR threshold, each additional spectral efficiency of the plurality of additional spectral efficiencies associated with a respective additional modulation format of the plurality of modulation formats; and

identifying a particular additional modulation format of the plurality of modulation formats that corresponds to a maximum additional spectral efficiency of the plurality of additional spectral efficiencies.

6. The method of claim 5, wherein the integration of the PDF of the SNR of the signal above the additional SNR threshold is greater than the integration of the PDF of the SNR of the signal above the SNR threshold.

7. The method of claim 6, wherein the maximum additional spectral efficiency that corresponds to the particular additional modulation format is less than the maximum spectral efficiency that corresponds to the particular modulation format.

8. The method of claim 1, further comprising:

identifying a second optical route between the pair of nodes, wherein the second optical route is associated with the desired availability;

determining a second probability density function (PDF) of the signal-to-noise ratio (SNR) of the signal of the second optical route;

determining a second SNR threshold such that an integration of the PDF of the SNR of the signal above the second SNR threshold corresponds to the desired availability of the second optical route;

determining a second plurality of spectral efficiencies that corresponds to the second SNR threshold, each second spectral efficiency of the plurality of second spectral efficiencies associated with a respective second modulation format of the plurality of modulation formats; and

identifying a particular second modulation format of the plurality of modulation formats that corresponds to a second maximum spectral efficiency of the plurality of second spectral efficiencies.

9. A system for assigning a modulation format in optical networks, the system comprising a processor having access to memory media storing instructions executable by the processor to:

identifying a pair of nodes of a plurality of nodes of a virtual optical network (VON);

identifying an optical route between the pair of nodes;

determining a desired availability of the optical route;

determining a probability density function (PDF) of a signal-to-noise ratio (SNR) of a signal of the optical route;

determining a SNR threshold such that an integration of the PDF of the SNR of the signal above the SNR threshold corresponds to the desired availability of the optical route;

determining a plurality of spectral efficiencies that corresponds to the SNR threshold, each spectral efficiency of the plurality of spectral efficiencies associated with a respective modulation format of a plurality of modulation formats;

identifying a particular modulation format of the plurality of modulation formats that corresponds to a maximum spectral efficiency of the plurality of spectral efficiencies;

assigning the particular modulation format to the virtual optical network; and

transmitting or receiving traffic over the virtual optical network using the particular modulation format.

10. The system of claim 9, wherein identifying the particular modulation format includes identifying parameters of the particular modulation format.

11. The system of claim 10, wherein the parameters include probabilistic shaping (PS) parameters or time-domain hybrid quadrature amplitude modulation (TDHQ) parameters.

12. The system of claim 9, the instructions further comprising determining a baud rate based on the maximum spectral efficiency.

13. The system of claim 9, the instructions further comprising:

determining an additional desired availability of the optical route;

determining an additional SNR threshold such than an integration of the PDF of the SNR of the signal above the additional SNR threshold corresponds to the additional desired availability of the optical route;

determining an additional plurality of spectral efficiencies that corresponds to the additional SNR threshold, each additional spectral efficiency of the plurality of additional spectral efficiencies associated with a respective additional modulation format of the plurality of modulation formats; and

identifying a particular additional modulation format of the plurality of modulation formats that corresponds to a maximum additional spectral efficiency of the plurality of additional spectral efficiencies.

14. The system of claim 13, wherein the integration of the PDF of the SNR of the signal above the additional SNR threshold is greater than the integration of the PDF of the SNR of the signal above the SNR threshold.

15. The system of claim 14, wherein the maximum additional spectral efficiency that corresponds to the particular additional modulation format is less than the maximum spectral efficiency that corresponds to the particular modulation format.

16. The system of claim 9, the instructions further comprising:

identifying a second optical route between the pair of nodes, wherein the second optical route is associated with the desired availability;

determining a second probability density function (PDF) of the signal-to-noise ratio (SNR) of the signal of the second optical route;

determining a second SNR threshold such that an integration of the PDF of the SNR of the signal above the second SNR threshold corresponds to the desired availability of the second optical route;

determining a second plurality of spectral efficiencies that corresponds to the second SNR threshold, each second spectral efficiency of the plurality of second spectral efficiencies associated with a respective second modulation format of the plurality of modulation formats; and

identifying a particular second modulation format of the plurality of modulation formats that corresponds to a second maximum spectral efficiency of the plurality of second spectral efficiencies.