Optical subchannel routing, protection switching and security

• US 10,630,418 B2
• Filed: 12/21/2017
• Issued: 04/21/2020
• Est. Priority Date: 12/08/2009
• Status: Active Grant

• Current Assignee: Snell Holdings, LLC (Treq Labs, Inc.)
• Original Assignee: Snell Holdings, LLC (Treq Labs, Inc.)
• Inventors: Barnard, Chris Wilhelm
• Primary Examiner(s): Li, Shi K
• Application Number:
  US15/851,673
• Publication Number:
  US 20180167159A1
• Time in Patent Office: 852 Days
• CPC Class Codes: H04B 10/0793 Network aspects, e.g. central monitoring of transmission parameters
• CPC Class Codes: H04B 10/572 Wavelength control
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems
• CPC Class Codes: H04J 14/0201 Add-and-drop multiplexing
• CPC Class Codes: H04J 14/0287 Protection in WDM systems
• CPC Class Codes: H04J 14/0293 Optical channel protection
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]
• CPC Class Codes: H04Q 11/0066 Provisions for optical burst or packet networks
• CPC Class Codes: H04Q 2011/0081 Fault tolerance; Redundancy; Recovery; Reconfigurability

Abstract

The present invention includes novel techniques, apparatus, and systems for optical WDM communications. Tunable lasers are employed to generate subcarrier frequencies representing subchannels of an ITU channel to which client signals can be mapped. Client circuits can be divided and combined before being mapped, independent of one another, to individual subchannels within and across ITU channels. Subchannels may be independently routed to a single subchannel receiver filter, such that each subchannel detected at the receiver may come from a different source location. Network architectures and subchannel transponders, muxponders and crossponders are disclosed, and techniques are employed (at the subchannel level/layer), to facilitate the desired optical routing, switching, concatenation and protection of client circuits mapped to these subchannels across the nodes of a WDM network. Subchannel hopping may also be used to increase the optical network security.

Claims

1. An optical network, comprising:

a plurality of nodes interconnected by fiber optic cables, each cable capable of transmitting one or more of a plurality of optical channels, each optical channel including a plurality of optical subchannels, each node including a plurality of lasers that respectively generate the plurality of subchannel frequencies that represent the plurality of optical subchannels;

a subchannel mapper at each node that maps a plurality of client signals to a corresponding plurality of optical subchannels; and

means for routing one or more of the plurality of client signals mapped to the corresponding one or more of the plurality of optical subchannels from a first to a second of the plurality of nodes by selecting one or more of the plurality of optical subchannels associated with the second of the plurality of nodes, wherein the means for routing comprises a software-controlled routing table that;

assigns the client signals to requested output ports of a desired destination node of the optical network;

assigns available subchannel frequencies to client signals based on the requested output port; and

communicates assignments of client signals, output ports and subchannel frequencies among the nodes of the optical network.

2. The optical network of claim 1, wherein at least one node comprising a fixed add/drop filter to transmit and receive the plurality of optical subchannels.

3. The optical network of claim 1, wherein at least one node comprising a reconfigurable add/drop filter to be remotely reconfigured to transmit and receive the plurality of optical subchannels.

4. The optical network of claim 1, wherein each of the plurality of lasers corresponding to the respective one of the plurality of optical subchannels is selected from a group consisting of:

a tunable frequency laser, and a fixed frequency laser.

5. The optical network of claim 1, wherein the plurality of lasers at one or more of the plurality of nodes to be set to one or more of the plurality of optical subchannels for which another one or more of the plurality of nodes have corresponding filters to receive the plurality of optical sub channels.

6. The optical network of claim 1 wherein the means for routing one or more of the plurality of client signals mapped to the corresponding one or more of the plurality of optical subchannels from a first to a second of the plurality of nodes by selecting one or more of the plurality of optical subchannels associated with the second of the plurality of nodes comprises tuning the plurality of lasers at the first of the plurality of nodes to the one or more of plurality of optical subchannels associated with the second of the plurality of nodes.

7. The optical network of claim 1, wherein information in the software-controlled routing table is output to a user, the information including one or more of the following:

a hardware availability, deployed status and current state of use of the plurality of channels and the plurality of optical subchannels;

one or more performance metrics of the plurality of channels and the plurality of optical subchannels, including bit error rate (BER), power level, optical signal-noise ratio (OSNR), chromatic dispersion (CD), polarization-mode dispersion (PMD), and nonlinear fiber penalties including cross-phase modulation and four-wave mixing;

node status, including whether a node will add, drop or pass-through a particular one of the plurality of client signals; and

an overall map illustrating channel and subchannel connections.

8. The optical network of claim 1, further comprising at least one of:

optical cross-connect switches, electronic cross-connect switches, and electronic packet switches, that can assign each of the plurality of client signals to any of the plurality of subchannel frequencies that is available to rout any one of the plurality of client signals to an available port of one more of the plurality of nodes in the optical network.

9. The optical network of claim 1, wherein the means for routing comprises a first network route that designates an origin for a first of the plurality of client signals at a first of the plurality of nodes, and a destination for the first of the plurality of client signals at a second of the plurality of nodes;

and

wherein the plurality of lasers comprises a tunable laser at the first of the plurality of nodes to set a first of the plurality of subchannel frequencies for which the second of the plurality of nodes has a filter to receive signals transmitted at the first of the plurality of subchannel frequencies.

10. The optical network of claim 9, wherein the means for routing comprises a second network route that designates an origin for a second of the plurality of client signals at the first of the plurality of nodes, and a destination for the second of the plurality of client signals at a third of the plurality of nodes;

and

wherein the tunable laser at the first of the plurality of nodes to set a second of the plurality of subchannel frequencies for which the third of the plurality of nodes has a filter to receive signals transmitted at the second of the plurality of subchannel frequencies.

11. In an optical network having a plurality of nodes interconnected by fiber optic cables, each cable capable of transmitting one or more of a plurality of optical channels, each optical channel including a plurality of optical subchannels, each node including a plurality of lasers that respectively generate the plurality of subchannel frequencies that represent the plurality of optical subchannels, a method comprising:

mapping at each node a plurality of client signals to a corresponding plurality of optical subchannels; and

routing one or more of the plurality of client signals mapped to the corresponding one or more of the plurality of optical subchannels from a first to a second of the plurality of nodes by selecting one or more of the plurality of optical subchannels associated with the second of the plurality of nodes, wherein routing the one or more of the plurality of client signals comprises a software-controlled routing table that performs the following functions;

assigns the client signals to requested output ports of a desired destination node of the optical network;

assigns available subchannel frequencies to client signals based on the requested output port; and

communicates assignments of client signals, output ports and subchannel frequencies among the nodes of the optical network.

12. The method of claim 11 wherein routing one or more of the plurality of client signals mapped to the corresponding one or more of the plurality of optical subchannels from a first to a second of the plurality of nodes by selecting one or more of the plurality of optical subchannels associated with the second of the plurality of nodes comprises tuning the plurality of lasers at the first of the plurality of nodes to the one or more of plurality of optical subchannels associated with the second of the plurality of nodes.