Optical transport having full and flexible bandwidth and channel utilization

• US 9,391,732 B2
• Filed: 02/03/2014
• Issued: 07/12/2016
• Est. Priority Date: 06/15/2011
• Status: Active Grant

• Current Assignee: Ciena Corporation
• Original Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Inventors: Wellbrock, Glenn A., Xia, Tiejun J.
• Primary Examiner(s): SINGH, DALZID E
• Application Number:
  US14/171,039
• Publication Number:
  US 20150288478A1
• Time in Patent Office: 890 Days
• US Class Current: 1/1
• 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; 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; and

a network management module comprising;

a memory, wherein the memory stores instructions; and

a processor, wherein the processor executes the instructions to;

examine a bandwidth allocation of an optical spectrum;

identify whether another bandwidth location can be used to service one of the non-fixed number of optical channels based on whether an assignment of the one of the non-fixed optical channels to the other bandwidth location creates a contiguous amount of unused bandwidth that is greater than a contiguous amount of unused bandwidth if the one of the non-fixed optical channels is not assigned to the other bandwidth location;

assign one or more optical carriers belonging to the one of the non-fixed optical channels to the other bandwidth location in response to an identification that the other bandwidth location can be used to service the one of the non-fixed optical channels and the assignment creates the contiguous amount of unused bandwidth that is greater than the contiguous amount of unused bandwidth if the one of the non-fixed optical channels is not assigned to the other bandwidth location; and

shift optical network traffic to the one or more assigned optical carriers of the other bandwidth location.

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.

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 processor further executes the instructions to:

configure the non-fixed number of optical channels via the one or more transponders and the ROADM, wherein a 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.

5. The optical node of claim 1, wherein the

one or more transponders comprise:

a single-carrier transmitter or a multi-carrier transmitter; and

a single-carrier receiver or a multi-carrier receiver.

6. The optical node of claim 1, wherein the processor further executes the instructions to:

examine, identify, assign, and shift based on a proactive triggering event or a reactive triggering event.

7. 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 a network management module.

8. The optical node of claim 1, wherein no channel spacing is used relative to at least two of the non-fixed number of optical channels.

9. 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;

a memory, wherein the memory stores instructions; and

a processor, wherein the processor executes the instructions 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;

select one of the non-fixed optical channels;

determine whether there is another available light path that is shorter than an existing light path being used to support the one of the non-fixed optical channels;

identify an available bandwidth of the other available light path in response to a determination that there is the other available light path that is shorter;

determine 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;

switch the one of the non-fixed optical channels to the other available light path in response to a determination that the higher modulation format that uses less bandwidth can be used; and

configure the one of the non-fixed optical channels based on the higher modulation format.

10. The optical communication system of claim 9, 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.

11. The optical communication system of claim 9, 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.

12. The optical communication system of claim 9, 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.

13. The optical communication system of claim 9, wherein the transport system includes a dense wavelength division multiplexing transport system.

14. The optical communication system of claim 9, wherein the

one or more transponders comprise:

a single-carrier transmitter or a multi-carrier transmitter; and

a single-carrier receiver or a multi-carrier receiver.

15. The optical communication system of claim 9, wherein optical spectrum to which the one of the non-fixed optical channels is switched does not provide channel spacing relative to the one of the non-fixed optical channels.

16. The optical communication system of claim 9, wherein the processor further executes the instructions to:

detect a topology change in an optical network to which the optical communication system belongs, and wherein, when determining whether there is another available light path, the processor further executes the instruction to;

determine whether there is another available light path that is shorter than the existing light path being used to support the one of the non-fixed optical channels in response to the detection of the topology change.

17. An optical communication system comprising:

optical nodes, wherein each optical node comprises;

a network management module;

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, and the optical communication system further comprising

a network management system comprising;

a memory, wherein the memory stores instructions; and

a processor, wherein the processor executes the instructions to;

select one of the non-fixed optical channels;

determine whether there is another available light path that is shorter than an existing light path being used to support the one of the non-fixed optical channels;

identify an available bandwidth of the other available light path in response to a determination that there is the other available light path that is shorter;

determine 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;

switch the one of the non-fixed optical channels to the other available light path in response to a determination that the higher modulation format that uses less bandwidth can be used;

configure the one of the non-fixed optical channels based on the higher modulation format; and

configure at least one of the network management modules of at least one of the optical nodes with a configuration of the one of the non-fixed optical channels.

18. The optical communication system of claim 17, wherein each optical node further comprises:

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.

19. The optical communication system of claim 17, 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.

20. The optical communication system of claim 17,

wherein the processor further executes the instructions to:

detect a topology change in an optical network to which the optical communication system belongs, and wherein, when determining whether there is another available light path that is shorter, the processor further executes the instruction to;

determine whether there is another available light path that is shorter than the existing light path being used to support the one of the non-fixed optical channels in response to the detection of the topology change.