Optical transport having full and flexible bandwidth and channel utilization

• US 8,644,710 B2
• Filed: 06/15/2011
• Issued: 02/04/2014
• Est. Priority Date: 06/15/2011
• Status: Active Grant

• Current Assignee: Ciena Corporation
• Original Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Inventors: XIA, Tiejun J., Wellbrock, Glenn A.
• Primary Examiner(s): SINGH, DALZID E
• Application Number:
  US13/160,717
• Publication Number:
  US 20120321306A1
• Time in Patent Office: 965 Days
• Field of Search: 398/45, 398/48, 398/49, 398/83
• US Class Current: 398/83
• CPC Class Codes: H04B 10/27 Arrangements for networking
• CPC Class Codes: H04J 14/021 Reconfigurable arrangements, e.g. reconfigurable optical add/drop multiplexers [ROADM] or tunable optical add/drop multiplexers [TOADM]
• CPC Class Codes: H04J 14/0212 using optical switches or wavelength selective switches [WSS]
• CPC Class Codes: H04J 14/0217 Multi-degree architectures, e.g. having a connection degree greater than two
• 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: H04Q 11/0062 Network aspects
• CPC Class Codes: H04Q 2011/0064 Arbitration, scheduling or medium access control aspects

Abstract

Optical nodes in an optical network may provide directionless, colorless, contentionless, and gridless transmission, reception, and switching of optical signals in which a non-fixed number of optical channels and a non-fixed bandwidth for each optical channel is used. Optical nodes can use the full extent of the optical bandwidth due to the absence of channel spacing.

Claims

1. An optical node comprising:

one or more transponders;

a reconfigurable optical add-drop multiplexer (ROADM) that is directionless, colorless, contentionless, and gridless comprising;

flexible spectrum selective switches; and

add/drop ports, wherein the one or more transponders and the ROADM are configured to;

transmit, receive, and switch a non-fixed number of optical channels based on an optical network demand, wherein an optical bandwidth associated with each optical channel is non-fixed; and

a network management module comprising;

one or more processors to configure the network management module to;

configure the non-fixed number of optical channels via the one or more transponders and the ROADM, wherein the number of optical carriers for each optical channel and a data rate for each optical channel is adjusted dynamically based on the optical network demand.

2. The optical node of claim 1, further comprising:

power splitters; and

wherein the ROADM is configured to;

add or drop the non-fixed number of optical channels according to the non-fixed optical bandwidth associated with each optical channel, and wherein no channel spacing is used relative to at least two of the non-fixed number of optical channels.

3. The optical node of claim 1, wherein the optical channels are dense wavelength division multiplexing optical channels.

4. The optical node of claim 1, wherein the one or more transponders include one or more lasers and one or more carrier generators capable of producing a single carrier optical channel and a multicarrier optical channel.

5. The optical node of claim 1, wherein the one or more transponders are configured to:

set a data rate for each optical channel;

set a number of optical carriers for each optical channel;

set a modulation format for each optical carrier;

set a total bandwidth for each optical channel; and

set a starting frequency and an ending frequency for each optical channel based on instructions from the network management module.

6. An optical communication system comprising:

a transport system comprising optical nodes connected to optical fibers, wherein each optical node comprises;

a network management module;

one or more transponders;

a reconfigurable optical add-drop multiplexer (ROADM) that is directionless, colorless, contentionless, and gridless; and

the transport system further comprising;

a network management system comprising;

one or more memories storing instructions; and

one or more processors to execute the instructions and configure the network management system to;

configure the one or more transponders and the ROADM of the optical nodes, via the network management module, to;

transmit, receive, and switch a non-fixed number of optical channels based on an optical network demand, wherein an optical bandwidth associated with each optical channel is non-fixed, wherein the one or more transponders are configured to;

set a data rate for each optical channel;

set a number of optical carriers for each optical channel;

set a modulation format for each optical carrier;

set a total bandwidth for each optical channel; and

set a starting frequency and an ending frequency for each optical channel according to a gridless use of an optical spectrum.

7. The optical communication system of claim 6, wherein the one or more transponders are configured to:

produce a single carrier optical channel and a multicarrier optical channel.

8. The optical communication system of claim 6, wherein the ROADM comprises:

flexible spectrum selective switches; and

add/drop ports, wherein the flexible spectrum selective switches are configured to;

switch the non-fixed number of optical signals to the add/drop ports according to the non-fixed optical bandwidth associated with each optical channel.

9. The optical communication system of claim 6, wherein the ROADM comprises:

power splitters, and wherein no channel spacing is used relative to at least two of the non-fixed number of optical channels.

10. The optical communication system of claim 6, wherein the transport system includes a dense wavelength division multiplexing transport system.

11. A method comprising:

examining, by a device, a bandwidth allocation of an optical spectrum;

identifying, by the device, whether another bandwidth location can be used to service an optical channel based on whether an assignment of the optical channel to the other bandwidth location creates a contiguous amount of unused bandwidth that is greater than a contiguous amount of unused bandwidth if the optical channel is not assigned to the other bandwidth location;

assigning, by the device, one or more optical carriers belonging to the optical channel to the other bandwidth location when it is identified that the other bandwidth location can be used to service the optical channel and the assignment creates the contiguous unused bandwidth that is greater than the contiguous amount of unused bandwidth if the optical channel is not assigned to the other bandwidth location;

shifting, by the device, optical network traffic to the one or more assigned optical carriers of the other bandwidth location; and

releasing, by the device, one or more optical carriers of the optical channel associated with an original bandwidth location.

12. The method of claim 11, wherein the other bandwidth location does not provide optical spectrum for channel spacing relative to the optical channel.

13. The method of claim 11, further comprising:

identifying whether a bandwidth location can be used to service another optical channel based on whether a second assignment of the other optical channel to the bandwidth location creates a second contiguous amount of unused bandwidth that is greater than a contiguous amount of unused bandwidth if the other optical channel is not assigned to the bandwidth location;

assigning one or more optical carriers belonging to the other optical channel to the bandwidth location when it is identified that the bandwidth location can be used to service the other optical channel and the second assignment creates the second contiguous amount of unused bandwidth that is greater than the contiguous amount of unused bandwidth if the other optical channel is not assigned to the bandwidth location;

shifting optical network traffic to the one or more assigned optical carriers of the bandwidth location; and

releasing one or more optical carriers of the other optical channel associated with a second original bandwidth location.

14. The method of claim 11, further comprising:

assigning a new optical channel to the original bandwidth location, wherein the original bandwidth location does not provide optical spectrum for channel spacing relative to the new optical channel.

15. The method of claim 11, wherein the examining, the identifying, the assigning, the shifting, and the releasing is performed based on a proactive triggering event or a reactive triggering event.

16. A method, comprising:

determining, by a device, a channel data rate of an optical network traffic flow demand;

identifying, by the device, one or more candidate light paths to satisfy the optical network traffic flow demand based on an identification of end nodes pertaining to the optical network traffic flow demand;

selecting, by the device, a modulation format for each carrier and a number of carriers required to satisfy the optical network traffic flow demand for each of the one or more candidate light paths;

selecting, by the device, a total bandwidth for each of the one or more candidate light paths based on the selected modulation format;

searching, by the device, an available bandwidth for each of the one or more candidate light paths based on the total bandwidth;

identifying, by the device, whether one or more of the one or more candidate light paths do not have the available total bandwidth;

removing, by the device, the one or more of the one or more candidate light paths as a candidate light path if it is identified that the one or more of the one or more light paths do not have the available total bandwidth; and

selecting, by the device, one of the one or more candidate light paths that has the available total bandwidth.

17. The method of claim 16, wherein the selecting further comprises:

selecting the one of the one or more candidate light paths based on one or more of a distance or a spectral efficiency pertaining to the one of the one or more candidate light paths.

18. The method of claim 16, further comprising:

configuring a channel along the one of the one or more candidate light paths based on the selected modulation format for each carrier and the number of carriers, and the available total bandwidth.

19. The method of claim 18, wherein the available total bandwidth does not provide optical spectrum for channel spacing relative to the channel.

20. The method of claim 16, wherein the number of carriers is greater than one.

21. A method comprising:

selecting, by a device, an optical channel;

determining, by the device, whether there is another available light path that is shorter than an existing light path being used to support the optical channel;

identifying, by the device, an available bandwidth of the other available light when it is determined that there is the other available light path that is shorter;

determining, by the device, whether a higher modulation format that uses less bandwidth relative to a modulation format and bandwidth being used along the existing light path can be used;

switching, by the device, the optical channel to the other available light path when it is determined that the higher modulation format that uses less bandwidth can be used; and

configuring, by the device, the optical channel based on the higher modulation format.

22. The method of claim 21, further comprising:

repeating the method of claim 21 relative to one or more other selected optical channels.

23. The method of claim 21, wherein optical spectrum to which the optical channel is switched does not provide channel spacing relative to the optical channel.

24. The method of claim 21, wherein method claim 21 is performed based on a proactive triggering event or a reactive triggering event.

25. The method of claim 24, wherein the reactive triggering event includes when a topology of an optical network changes.

26. An optical node comprising:

one or more transponders; and

a reconfigurable optical add-drop multiplexer (ROADM) that is directionless, colorless, contentionless, and gridless comprising;

flexible spectrum selective switches; and

add/drop ports, wherein the one or more transponders and the ROADM are configured to;

transmit, receive, and switch a non-fixed number of optical channels based on an optical network demand, wherein an optical bandwidth associated with each optical channel is non-fixed, wherein the one or more transponders are configured to;

set a data rate for each optical channel;

set a number of optical carriers for each optical channel;

set a modulation format for each optical carrier;

set a total bandwidth for each optical channel; and

set a starting frequency and an ending frequency for each optical channel according to a gridless use of an optical spectrum.