Port-to-port, non-blocking, scalable optical router architecture and method for routing optical traffic Number:7,426,210 from the United States Patent and Trademark Office (PTO) owispatent One embodiment of the present invention includes a router comprising an ingress edge unit with one or more ports and an egress edge unit with one or more ports connected by a switch fabric. The ingress edge unit can receive optical data and convert the optical data into a plurality of micro lambdas. The ingress edge unit can convert the incoming data to micro lambdas by generating a series of short-term parallel data bursts across multiple wavelengths. The ingress edge unit can also wavelength division multiplex and time domain multiplex each micro lambda for transmission to the switch fabric in a particular order. The switch fabric can receive the plurality of micro lambdas and route the plurality of micro lambdas to the plurality of egress edge units in a non-blocking manner.<H architecture, scalable, Port, to, port, no, 7426210.html, Patent, pto, 7426210

Title: Port-to-port, non-blocking, scalable optical router architecture and method for routing optical traffic

Abstract: One embodiment of the present invention includes a router comprising an ingress edge unit with one or more ports and an egress edge unit with one or more ports connected by a switch fabric. The ingress edge unit can receive optical data and convert the optical data into a plurality of micro lambdas. The ingress edge unit can convert the incoming data to micro lambdas by generating a series of short-term parallel data bursts across multiple wavelengths. The ingress edge unit can also wavelength division multiplex and time domain multiplex each micro lambda for transmission to the switch fabric in a particular order. The switch fabric can receive the plurality of micro lambdas and route the plurality of micro lambdas to the plurality of egress edge units in a non-blocking manner.

Patent Number: 7,426,210 Issued on 09/16/2008 to Miles, et al.

Inventors: Miles; Larry L. (Garland, TX), Tamil; Lakshman S. (Plano, TX), Rothrock; Scott A. (Plano, TX), Posey, Jr.; Nolan J. (Allen, TX), Aicklen; Gregory H. (Richardson, TX)
Assignee: YT Networks Capital, LLC (Wilmington, DE)

Appl. No.: 10/115,564

Filed: April 3, 2002

Related U.S. Patent Documents


Application Number	Filing Date	Patent Number	Issue Date
60281176	Apr., 2001

Current U.S. Class: 370/400 ; 370/429; 398/47

Current International Class: H04L 12/56 (20060101)

Field of Search: 370/400,401,402,422,423,427,428,429,430,531-545 398/45,47,49,50

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Primary Examiner: Pham; Chi H.
Assistant Examiner: Mew; Kevin
Attorney, Agent or Firm: Connolly Bove Lodge & Hutz LLP Wyche; Myron Keith

Parent Case Text

RELATED APPLICATIONS

This application claims priority under 35 U.S.C. .sctn.119 to U.S. Provisional Patent Application No. 60/281,176 entitled "System and Method for Scalable Architecture System" and filed on Apr. 3, 2001, which is hereby fully incorporated by reference herein.

Claims

What is claimed is:

1. A router to be coupled to a plurality of data lines, comprising: a core controller; a plurality of egress edge units coupled to said core controller, said plurality of egress edge units including at least one egress port; a plurality of ingress edge units coupled to said core controller and to communicate with said plurality of egress edge units; and an optical switch fabric to communicate with the plurality of ingress edge units and egress edge units to receives the plurality of micro lambdas from the plurality of ingress edge units and to route each micro lambda in a non-blocking manner through the optical switch fabric to the egress edge unit associated with the particular destination port for that micro lambda, wherein each ingress edge unit is to receive optical data, convert the optical data into a plurality of micro lambdas, time wavelength division multiplex each micro lambda and transmit each micro lambda to an egress edge unit; wherein each micro lambda comprises optical data intended for a particular destination port at one of the plurality of egress edge units; wherein the plurality of egress edge units are to receive the plurality of micro lambdas and wherein each egress edge unit is to route each micro lambda received at the corresponding egress edge unit to the particular destination port for that micro lambda; wherein each ingress edge unit is to time wavelength division multiplex each micro lambda at the corresponding ingress edge unit by: wavelength division multiplexing each micro lambda at the corresponding ingress edge unit; and rearranging the micro lambdas at the corresponding ingress edge unit in the time domain for transmission according to a particular schedule; wherein the core controller is to establish a schedule pattern for time domain multiplexing of micro lambdas to control the arrival of each of the plurality of micro lambdas at the optical switch fabric so as to avoid blocking at the optical switch fabric; and wherein the core controller comprises: a switch controller to communicate with the optical switch fabric; and a core scheduler to communicate with the switch controller and to communicate with each of the plurality of ingress edge units via a plurality of control links; wherein said core scheduler is to monitor the plurality of ingress edge units to determine a scheduling pattern for each of the plurality of ingress edge units, wherein the scheduling pattern is to cause each ingress edge unit to transmit micro lambdas to the optical switch fabric so that no two micro lambdas destined for a single egress edge unit arrive at the optical switch fabric during an identical switching time interval; and wherein the switch controller is to create a unique path through the optical switch fabric for each micro lambda arriving at the optical switch fabric during the identical switching time interval.

2. The router of claim 1, further comprising: a plurality of ingress micro lambda links, wherein each micro lambda link is to connect one of the plurality of ingress edge units to the optical switch fabric; a plurality of egress micro lambda links, wherein each micro lambda link is to connect one of the plurality of edge units to the optical switch fabric; and wherein the plurality of micro lambdas to be created at the plurality of ingress edge units are to be transmitted to the optical switch fabric over the plurality of ingress micro lambda links and further wherein the plurality of micro lambdas are to be transmitted to the plurality of egress edge units from the optical switch fabric over the plurality of egress micro lambda links.

3. A router to be coupled to a plurality of data lines, comprising: a core controller; a plurality of egress edge units coupled to said core controller, said plurality of egress edge units including at least one egress port; a plurality of ingress edge units coupled to said core controller and to communicate with said plurality of egress edge units; and an optical switch fabric to communicate with the plurality of ingress edge units and egress edge units to receives the plurality of micro lambdas from the plurality of ingress edge units and to route each micro lambda in a non-blocking manner through the optical switch fabric to the egress edge unit associated with the particular destination port for that micro lambda; a plurality of ingress micro lambda links, wherein each micro lambda link is to connect one of the plurality of ingress edge units to the optical switch fabric; a plurality of egress micro lambda links, wherein each micro lambda link is to connect one of the plurality of edge units to the optical switch fabric; wherein each ingress edge unit is to receive optical data, convert the optical data into a plurality of micro lambdas, time wavelength division multiplex each micro lambda and transmit each micro lambda to an egress edge unit; wherein each micro lambda comprises optical data intended for a particular destination port at one of the plurality of egress edge units; wherein the plurality of egress edge units are to receive the plurality of micro lambdas and wherein each egress edge unit is to route each micro lambda received at the corresponding egress edge unit to the particular destination port for that micro lambda; wherein each ingress edge unit is to time wavelength division multiplex each micro lambda at the corresponding ingress edge unit by: wavelength division multiplexing each micro lambda at the corresponding ingress edge unit; and rearranging the micro lambdas at the corresponding ingress edge unit in the time domain for transmission according to a particular schedule; wherein the core controller is to establish a schedule pattern for time domain multiplexing of micro lambdas to control the arrival of each of the plurality of micro lambdas at the optical switch fabric so as to avoid blocking at the optical switch fabric; wherein the plurality of micro lambdas to be created at the plurality of ingress edge units are to be transmitted to the optical switch fabric over the plurality of ingress micro lambda links and further wherein the plurality of micro lambdas are to be transmitted to the plurality of egress edge units from the optical switch fabric over the plurality of egress micro lambda links; and the router further comprising: a plurality of ingress control links, wherein each ingress control link is to connect an ingress edge unit to the core controller; a plurality of egress control links, wherein each egress control link is to connect an egress edge unit to the core controller; and wherein the core controller is to receive a plurality of pattern data from the plurality of ingress edge units that the core controller is to use to establish a pattern to be used to route the plurality of micro lambdas from the plurality of ingress edge units to the plurality of egress edge units.

4. The router of claim 3, wherein the core controller is to monitor a plurality of synchronization data at the plurality of ingress edge units via the ingress control data links and at the plurality of egress edge units via the egress control data links to synchronize data flow through the router; and wherein the core controller is to monitor a plurality of time information at each of the plurality of egress edge units via the egress control data links to verify data intended for each egress edge unit arrives at an appropriate time.

5. The router of claim 1, wherein each ingress edge unit is operable to: segregate incoming optical data into a plurality of subflows, wherein each subflow contains data destined for a particular destination port; generate a micro lambda from each subflow created at the corresponding ingress edge unit by converting each subflow into a parallel burst of data across multiple wavelengths; time domain multiplex each micro lambda generated at the corresponding ingress edge unit according to a schedule pattern received from the core controller; wavelength multiplex each micro lambda generated at the corresponding ingress edge unit; and transmit each micro lambda generated at the corresponding ingress edge unit to the switch fabric according to the schedule pattern.

6. A router to be coupled to a plurality of data lines, comprising: a core controller; a plurality of egress edge units coupled to said core controller, said plurality of egress edge units including at least one egress port; a plurality of ingress edge units coupled to said core controller and to communicate with said plurality of egress edge units; and an optical switch fabric to communicate with the plurality of ingress edge units and egress edge units to receives the plurality of micro lambdas from the plurality of ingress edge units and to route each micro lambda in a non-blocking manner through the optical switch fabric to the egress edge unit associated with the particular destination port for that micro lambda, wherein each ingress edge unit is to receive optical data, convert the optical data into a plurality of micro lambdas, time wavelength division multiplex each micro lambda and transmit each micro lambda to an egress edge unit; wherein each micro lambda comprises optical data intended for a particular destination port at one of the plurality of egress edge units; wherein the plurality of egress edge units are to receive the plurality of micro lambdas and wherein each egress edge unit is to route each micro lambda received at the corresponding egress edge unit to the particular destination port for that micro lambda; wherein each ingress edge unit is to time wavelength division multiplex each micro lambda at the corresponding ingress edge unit by: wavelength division multiplexing each micro lambda at the corresponding ingress edge unit; and rearranging the micro lambdas at the corresponding ingress edge unit in the time domain for transmission according to a particular schedule; wherein the core controller is to establish a schedule pattern for time domain multiplexing of micro lambdas to control the arrival of each of the plurality of micro lambdas at the optical switch fabric so as to avoid blocking at the optical switch fabric; and wherein each ingress edge unit further comprises: a plurality of ingress ports; an ingress interface associated with each ingress port, each ingress interface operable to segregate incoming optical data into a plurality of subflows, wherein each subflow contains data intended for a particular destination port; and a TWDM multiplexer operable to: receive subflows from each of the ingress interfaces at the corresponding ingress edge unit; generate a micro lambda from each received subflow; time multiplex each micro lambda at the corresponding ingress edge unit according to a schedule pattern received from the core controller; wavelength multiplex each micro lambda at the corresponding ingress edge unit; and transmit each micro lambda at the corresponding ingress edge unit to the switch fabric according to the schedule pattern.

7. A router to be coupled to a plurality of data lines, comprising: a core controller; a plurality of egress edge units coupled to said core controller, said plurality of egress edge units including at least one egress port; a plurality of ingress edge units coupled to said core controller and to communicate with said plurality of egress edge units; and an optical switch fabric to communicate with the plurality of ingress edge units and egress edge units to receives the plurality of micro lambdas from the plurality of ingress edge units and to route each micro lambda in a non-blocking manner through the optical switch fabric to the egress edge unit associated with the particular destination port for that micro lambda, wherein each ingress edge unit is to receive optical data, convert the optical data into a plurality of micro lambdas, time wavelength division multiplex each micro lambda and transmit each micro lambda to an egress edge unit; wherein each micro lambda comprises optical data intended for a particular destination port at one of the plurality of egress edge units; wherein the plurality of egress edge units are to receive the plurality of micro lambdas and wherein each egress edge unit is to route each micro lambda received at the corresponding egress edge unit to the particular destination port for that micro lambda; wherein each ingress edge unit is to time wavelength division multiplex each micro lambda at the corresponding ingress edge unit by: wavelength division multiplexing each micro lambda at the corresponding ingress edge unit; and rearranging the micro lambdas at the corresponding ingress edge unit in the time domain for transmission according to a particular schedule; wherein the core controller is to establish a schedule pattern for time domain multiplexing of micro lambdas to control the arrival of each of the plurality of micro lambdas at the optical switch fabric so as to avoid blocking at the optical switch fabric; and wherein each ingress edge unit further comprises: a plurality of ingress ports; an ingress interface associated with each ingress port, each ingress interface further comprising: a framer operable to read overhead data from an incoming data stream; a classifier operable to segregate data from the incoming data stream based on quality of service parameters; a quality of service queue operable to buffer incoming data according to quality of service; a plurality of input buffers, each input buffer capable of buffering a subflow worth of data to create a subflow; a TWDM multiplexer operable to receive subflows from the input buffers at the corresponding ingress interface and time multiplex the received subflows; a port scheduler to receive a port scheduling pattern from the core scheduler and to coordinate the creation and time domain multiplexing of subflows at the corresponding ingress interface; a TWDM converter operable to receive subflows from each ingress interface at the corresponding ingress edge unit, generate a micro lambda from each subflow at edge unit, and time multiplex each micro lambda at the corresponding edge unit; a DWDM multiplexer operable to: receive micro lambdas from the TWDM converter at the corresponding ingress edge unit and wavelength multiplex each micro lambda received from the TWDM converter; and transmit each micro lambda at the corresponding ingress edge unit to the optical switch fabric via a micro lambda link; and an edge scheduler to receive an edge scheduling pattern from the core controller and to coordinate the generation and time domain multiplexing of micro lambdas at the corresponding ingress edge unit.

8. The router of claim 7, wherein each ingress interface further comprises an OC-192 router.

9. The router of claim 8, wherein each subflow contains approximately 311 Mbps of data.

10. The router of claim 1, wherein each egress edge unit is operable to: receive micro lambdas destined for an egress port at the corresponding egress edge unit; demultiplex the received micro lambdas in the time and wavelength domains; convert each received micro lambda into a subflow; and concatenate each received subflow at the corresponding egress edge unit into a continuous outgoing data stream.

11. A router to be coupled to a plurality of data lines, comprising: a core controller; a plurality of egress edge units coupled to said core controller, said plurality of egress edge units including at least one egress port; a plurality of ingress edge units coupled to said core controller and to communicate with said plurality of egress edge units; and an optical switch fabric to communicate with the plurality of ingress edge units and egress edge units to receives the plurality of micro lambdas from the plurality of ingress edge units and to route each micro lambda in a non-blocking manner through the optical switch fabric to the egress edge unit associated with the particular destination port for that micro lambda, wherein each ingress edge unit is to receive optical data, convert the optical data into a plurality of micro lambdas, time wavelength division multiplex each micro lambda and transmit each micro lambda to an egress edge unit; wherein each micro lambda comprises optical data intended for a particular destination port at one of the plurality of egress edge units; wherein the plurality of egress edge units are to receive the plurality of micro lambdas and wherein each egress edge unit is to route each micro lambda received at the corresponding egress edge unit to the particular destination port for that micro lambda; wherein each ingress edge unit is to time wavelength division multiplex each micro lambda at the corresponding ingress edge unit by: wavelength division multiplexing each micro lambda at the corresponding ingress edge unit; and rearranging the micro lambdas at the corresponding ingress edge unit in the time domain for transmission according to a particular schedule; wherein the core controller is to establish a schedule pattern for time domain multiplexing of micro lambdas to control the arrival of each of the plurality of micro lambdas at the optical switch fabric so as to avoid blocking at the optical switch fabric; and wherein each egress edge unit further comprises: a DWDM demultiplexer operable to receive and wavelength demultiplex arriving micro lambdas destined for an egress port at the corresponding egress edge unit; a TWDM converter operable to receive micro lambdas from the DWDM demultiplexer at the corresponding egress edge unit, convert each micro lambda into a subflow and forward each subflow to an egress interface associated with the particular destination port for the data in the subflow; an edge scheduler operable to coordinate the forwarding of each subflow to the appropriate egress interface; and an egress interface associated with each egress port further comprising: a TWDM demultiplexer operable to receive subflows destined for the associated egress port and time demultiplex the subflows; a set of output buffers operable to buffer the subflows at the corresponding egress interface and forward the subflows to the associated egress port as an outgoing data stream; and a port scheduler operable to coordinate time demultiplexing and buffering of subflows at the corresponding egress interface.

12. The router of claim 11, wherein each egress interface further comprises: a framer operable to insert SONET frames in the outgoing data stream; and a traffic manager operable to perform burst smoothing on the outgoing data stream.

13. A router to be coupled to a plurality of data lines, comprising: a core controller; a plurality of egress edge units coupled to said core controller, said plurality of egress edge units including at least one egress port; a plurality of ingress edge units coupled to said core controller and to communicate with said plurality of egress edge units; and an optical switch fabric to communicate with the plurality of ingress edge units and egress edge units to receives the plurality of micro lambdas from the plurality of ingress edge units and to route each micro lambda in a non-blocking manner through the optical switch fabric to the egress edge unit associated with the particular destination port for that micro lambda, wherein each ingress edge unit is to receive optical data, convert the optical data into a plurality of micro lambdas, time wavelength division multiplex each micro lambda and transmit each micro lambda to an egress edge unit; wherein each micro lambda comprises optical data intended for a particular destination port at one of the plurality of egress edge units; wherein the plurality of egress edge units are to receive the plurality of micro lambdas and wherein each egress edge unit is to route each micro lambda received at the corresponding egress edge unit to the particular destination port for that micro lambda; wherein each ingress edge unit is to time wavelength division multiplex each micro lambda at the corresponding ingress edge unit by: wavelength division multiplexing each micro lambda at the corresponding ingress edge unit; and rearranging the micro lambdas at the corresponding ingress edge unit in the time domain for transmission according to a particular schedule; wherein the core controller is to establish a schedule pattern for time domain multiplexing of micro lambdas to control the arrival of each of the plurality of micro lambdas at the optical switch fabric so as to avoid blocking at the optical switch fabric; and wherein each micro lambda is to be routed using slot deflection routing to route each micro lambda from an ingress edge unit to an egress edge unit.

14. The router of claim 13, wherein each ingress edge unit is collocated with an egress edge unit to form an integrated edge unit.

15. A router coupled to a plurality of data lines, comprising: a core controller; a plurality of egress edge units coupled to said core controller, said plurality of egress edge units including at least one egress port; and a plurality of ingress edge units coupled to said core controller and in communication with said plurality of egress edge units, wherein each ingress edge unit receives optical data, converts the optical data into a plurality of micro lambdas, time wavelength division multiplexes each micro lambda and transmits each micro lambda to an egress edge unit; wherein each micro lambda comprises optical data intended for a particular destination port at one of the plurality of egress edge units; and wherein the plurality of egress edge units receives the plurality of micro lambdas and wherein each egress edge unit routes micro lambdas received at the corresponding egress edge unit to the particular destination port for that micro lambda; and wherein each ingress edge unit is operable to: segregate incoming optical data into a plurality of subflows, wherein each subflow contains data destined for a particular destination port; and generate a micro lambda from each subflow created at the corresponding ingress edge unit by converting each subflow into a parallel burst of data across multiple wavelengths.

16. The router of claim 15, wherein each egress edge unit is operable to: receive micro lambdas destined for an egress port at the corresponding egress edge unit; demultiplex the received micro lambdas in the time and wavelength domains; convert each received micro lambda into a subflow; and concatenate each received subflow at the corresponding egress edge unit into a continuous outgoing data stream.

17. A router coupled to a plurality of data lines, comprising: a core controller; a plurality of egress edge units coupled to said core controller, said plurality of egress edge units including at least one egress port; and a plurality of ingress edge units coupled to said core controller and in communication with said plurality of egress edge units, wherein each ingress edge unit receives optical data, converts the optical data into a plurality of micro lambdas, time wavelength division multiplexes each micro lambda and transmits each micro lambda to an egress edge unit; wherein each micro lambda comprises optical data intended for a particular destination port at one of the plurality of egress edge units; and wherein the plurality of egress edge units receives the plurality of micro lambdas and wherein each egress edge unit routes micro lambdas received at the corresponding egress edge unit to the particular destination port for that micro lambda; and wherein each ingress edge unit further comprises: a plurality of ingress ports; an ingress interface associated with each ingress port, each ingress interface further comprising: a framer operable to read overhead data from an incoming data stream.about. a classifier operable to segregate data from the incoming data stream based on quality of service parameters; a quality of service queue operable to buffer incoming data according to quality of service; a plurality of input buffers, each input buffer capable of buffering a subflow worth of data to create a subflow; a TWDM multiplexer operable to receive subflows from the input buffers at the corresponding ingress interface and time multiplex the received subflows; a port scheduler to coordinate the creation and time domain multiplexing of subflows at the corresponding ingress interface; a TWDM converter operable to receive subflows from each ingress interface at the corresponding ingress edge unit, generate a micro lambda from each subflow at edge unit, and time multiplex each micro lambda at the corresponding edge unit; a DWDM multiplexer operable to: receive micro lambdas from the TWDM converter at the corresponding ingress edge unit and wavelength multiplex each micro lambda received from the TWDM converter; and transmit each micro lambda to the egress edge unit associated with the particular destination port for that micro lambda; and an edge scheduler to coordinate the generation and time domain multiplexing of micro lambdas at the corresponding ingress edge unit.

18. A router coupled to a plurality of data lines, comprising: a core controller; a plurality of egress edge units coupled to said core controller, said plurality of egress edge units including at least one egress port; and a plurality of ingress edge units coupled to said core controller and in communication with said plurality of egress edge units, wherein each ingress edge unit receives optical data, converts the optical data into a plurality of micro lambdas, time wavelength division multiplexes each micro lambda and transmits each micro lambda to an egress edge unit; wherein each micro lambda comprises optical data intended for a particular destination port at one of the plurality of egress edge units; and wherein the plurality of egress edge units receives the plurality of micro lambdas and wherein each egress edge unit routes micro lambdas received at the corresponding egress edge unit to the particular destination port for that micro lambda; and wherein each ingress edge unit is further operable to: generate a plurality of subflows from the optical data; rearrange the subflows in the time domain according to a particular schedule; convert each subflow at the corresponding ingress edge unit into a micro lambda; wavelength division multiplex each micro lambda at the corresponding ingress edge unit; and transmit each micro lambda at the corresponding ingress edge unit according to the particular schedule.

19. A router for routing optical data, comprising: a core controller; an egress edge unit coupled to said core controller and comprising a plurality of egress edge ports; an ingress edge unit coupled to said core controller and comprising a plurality of ingress edge ports; and an optical switch fabric to communicate with the ingress edge unit and egress edge unit and to receive the plurality of micro lambdas from the ingress edge unit and to route each micro lambda in a non-blocking manner through the optical switch fabric to the egress edge unit; wherein the ingress edge unit is to segregate incoming optical data at each of the ingress edge ports into a plurality of subflows, each subflow containing data destined for a particular egress edge port, to convert each subflow into a micro lambda, to time wavelength division multiplex each micro lambda and to transmit each micro lambda; wherein the egress edge unit is to receive each micro lambda from the ingress edge unit, to time and wavelength demultiplex each micro lambda, to convert each micro lambda back into the corresponding subflow, to forward each subflow to the particular egress edge port to which that subflow is destined and to output the subflows as a data stream; wherein the ingress edge unit is to time wavelength division multiplex each micro lambda by: time domain multiplexing each micro lambda by transmitting each micro lambda in a particular wave slot according to a schedule pattern; and wavelength division multiplexing each micro lambda; wherein the core controller is to establish a schedule pattern for time domain multiplexing of micro lambdas to control the arrival of each of the plurality of micro lambdas at the optical switch fabric so as to avoid blocking at the optical switch fabric; and wherein the ingress edge unit further comprises: an ingress interface associated with each ingress edge port, each ingress interface operable to segregate incoming optical data into at least a portion of the plurality subflows; and a TWDM multiplexer operable to: receive the plurality of subflows from the ingress interfaces; generate a micro lambda from each received subflow; wavelength multiplex each micro lambda; and transmit each micro lambda to the switch fabric in the particular wave slot according to a schedule pattern.

20. A router for routing optical data, comprising: a core controller; an egress edge unit coupled to said core controller and comprising a plurality of egress edge ports; an ingress edge unit coupled to said core controller and comprising a plurality of ingress edge ports; and an optical switch fabric to communicate with the ingress edge unit and egress edge unit and to receive the plurality of micro lambdas from the ingress edge unit and to route each micro lambda in a non-blocking manner through the optical switch fabric to the egress edge unit; wherein the ingress edge unit is to segregate incoming optical data at each of the ingress edge ports into a plurality of subflows, each subflow containing data destined for a particular egress edge port, to convert each subflow into a micro lambda, to time wavelength division multiplex each micro lambda and to transmit each micro lambda; wherein the egress edge unit is to receive each micro lambda from the ingress edge unit, to time and wavelength demultiplex each micro lambda, to convert each micro lambda back into the corresponding subflow, to forward each subflow to the particular egress edge port to which that subflow is destined and to output the subflows as a data stream; wherein the ingress edge unit is to time wavelength division multiplex each micro lambda by: time domain multiplexing each micro lambda by transmitting each micro lambda in a particular wave slot according to a schedule pattern; and wavelength division multiplexing each micro lambda; wherein the core controller is to establish a schedule pattern for time domain multiplexing of micro lambdas to control the arrival of each of the plurality of micro lambdas at the optical switch fabric so as to avoid blocking at the optical switch fabric; and wherein the ingress edge unit further comprises: an ingress interface associated with each ingress port, each ingress interface further comprising: a framer operable to read overhead data from an incoming data stream a classifier operable to segregate data from the incoming data stream based on quality of service; a quality of service queue operable to buffer incoming data; a plurality of input buffers that buffer data to create a subflow for each input buffer; a TWDM multiplexer to receive subflows from the input buffers at the corresponding ingress interface and to time multiplex the received subflows; and a port scheduler that receives a port scheduling pattern from the core scheduler and coordinates the creation and time domain multiplexing of subflows at the corresponding ingress interface; a TWDM converter to receive the plurality of subflows from each ingress interface, generate a micro lambda from each subflow, and time multiplex the micro lambdas; a DWDM multiplexer to receive the micro lambdas from the TWDM converter, wavelength multiplex each received micro lambda and transmit each micro lambda during the particular wave slot for that micro lambda; and an edge scheduler to receive an edge scheduling pattern from the core controller and coordinate the generation, time domain multiplexing and transmission of the micro lambdas.

21. A router for routing optical data, comprising: a core controller; an egress edge unit coupled to said core controller and comprising a plurality of egress edge ports; and an ingress edge unit coupled to said core controller and comprising a plurality of ingress edge ports, wherein the ingress edge unit is to segregate incoming optical data at each of the ingress edge ports into a plurality of subflows, each subflow containing data destined for a particular egress edge port, to convert each subflow into a micro lambda, to time wavelength division multiplex each micro lambda and to transmit each micro lambda; wherein the egress edge unit is to receive each micro lambda from the ingress edge unit, to time and wavelength demultiplex each micro lambda, to convert each micro lambda back into the corresponding subflow, to forward each subflow to the particular egress edge port to which that subflow is destined and to output the subflows as a data stream, and wherein the egress edge unit further comprises: a DWDM demultiplexer to receive and to wavelength demultiplex arriving micro lambdas; a TWDM converter to receive micro lambdas from the DWDM demultiplexer, convert each micro lambda into a subflow and forward each subflow to an egress interface unit associated with the particular egress port to which that subflow is destined; an edge scheduler to coordinate the forwarding of each subflow to the appropriate egress interface; and an egress interface associated with each egress port, each egress interface further comprising: a TWDM demultiplexer to receive subflows destined for the associated egress port and to time demultiplex the subflows received at the corresponding egress interface; and a set of output buffers to buffer the subflows at the corresponding egress interface and forward the subflows to the associated egress port as an outgoing data stream; and a port scheduler to coordinate time demultiplexing and buffering of subflows at the corresponding egress interface.

22. A router for routing optical data, comprising: a core controller; an egress edge unit coupled to said core controller and comprising a plurality of egress edge ports; and an ingress edge unit coupled to said core controller and comprising a plurality of ingress edge ports, wherein the ingress edge unit is to segregate incoming optical data at each of the ingress edge ports into a plurality of subflows, each subflow containing data destined for a particular egress edge port, to convert each subflow into a micro lambda, to time wavelength division multiplex each micro lambda and to transmit each micro lambda; wherein the egress edge unit is to receive each micro lambda from the ingress edge unit, to time and wavelength demultiplex each micro lambda, to convert each micro lambda back into the corresponding subflow, to forward each subflow to the particular egress edge port to which that subflow is destined and to output the subflows as a data stream, and wherein the core controller comprises: a switch controller to communicate with the optical switch fabric; and a core scheduler to communicate with the switch controller and to communicate with each of the plurality of ingress edge units via a plurality of control links; and wherein said core scheduler is to monitor a plurality of ingress edge units to determine a scheduling pattern for each of the plurality of ingress edge units, wherein the scheduling pattern is to cause each ingress edge unit to transmit micro lambdas to the optical switch fabric so that no two micro lambdas destined for the egress edge unit arrive at the optical switch fabric during an identical switching time interval; and wherein the switch controller is to create a unique path through the optical switch fabric for each micro lambda arriving at the optical switch fabric during the identical switching time interval.

23. The router of claim 22, wherein the ingress edge unit is to time wavelength division multiplex each micro lambda by: time domain multiplexing each micro lambda by transmitting each micro lambda in a particular wave slot according to a schedule pattern; and wavelength division multiplexing each micro lambda.

24. The router of claim 23, further comprising: an optical switch fabric to communicate with the ingress edge unit and egress edge unit and to receive the plurality of micro lambdas from the ingress edge unit and to route each micro lambda in a non-blocking manner through the optical switch fabric to the egress edge unit; wherein the core controller is to establish a schedule pattern for time domain multiplexing of micro lambdas to control the arrival of each of the plurality of micro lambdas at the optical switch fabric so as to avoid blocking at the optical switch fabric.

25. A router for routing optical data, comprising: a core controller: an egress edge unit coupled to said core controller and comprising a plurality of egress edge ports; and an ingress edge unit coupled to said core controller and comprising a plurality of ingress edge ports; a switch fabric to receive each micro lambda from the ingress edge unit and route each micro lambda to the egress edge unit in a non-blocking manner; and a core controller to control the arrival of micro lambdas at the switch fabric in such a manner that each micro lambda flows from the ingress edge unit, through the switch fabric, to the egress edge unit without blocking; wherein the ingress edge unit is to segregate incoming optical data at each of the ingress edge ports into a plurality of subflows with each subflow containing data destined for a particular egress edge port, to time multiplex each subflow, to convert each subflow into a micro lambda, to wavelength multiplex each micro lambda and to transmit each micro lambda in a particular wave slot; wherein the egress edge unit is to receive each micro lambda from the ingress edge unit, to time and wavelength demultiplex each micro lambda, to convert each micro lambda back into the corresponding subflow, and to output the subflows as a continuous data stream; and wherein the core controller comprises: a switch controller to communicate with the optical switch fabric; wherein the core scheduler is communicatively coupled to the switch controller and each of the plurality of ingress edge units via a plurality of control links; and wherein said core scheduler is to monitor a plurality of ingress edge units to determine a scheduling pattern for each of the plurality of ingress edge units, wherein the scheduling pattern is to cause each ingress edge unit to transmit micro lambdas to the optical switch fabric so that no two micro lambdas destined for the egress edge unit arrive at the optical switch fabric during an identical switching time interval; and wherein the switch controller is to create a unique path through the optical switch fabric for each micro lambda arriving at the optical switch fabric during the identical switching time interval.

26. A method of routing optical data comprising: receiving an incoming optical data stream; segregating the incoming data stream into a plurality of subflows, wherein each subflow is destined for a particular egress port; generating a micro lambda from each subflow by converting each subflow into a parallel data burst across multiple wavelengths, wherein each micro lambda contains a subflow's worth of data; wavelength multiplexing each micro lambda; time domain multiplexing each micro lambda; and transmitting each micro lambda to an egress edge unit according to a particular schedule established by a core controller monitoring the incoming optical data stream; and developing a schedule pattern of wave slots such that no two micro lambdas destined for the same egress edge unit arrive at a switch fabric at the same time.

27. The method of claim 26, further comprising: time and wavelength demultiplexing each micro lambda; converting each micro lambda into the associated subflow; and transmitting an associated subflow to the particular destination port for which that associated subflow is destined.

28. The method of claim 26, further comprising performing burst smoothing at each egress port to create a continuous outgoing data stream.

29. The method of claim 26, further comprising routing each micro lambda through an optical switch fabric in a non-blocking manner.

30. The method of claim 26, wherein time domain multiplexing further comprises rearranging each micro lambda in the time domain according to the particular schedule.

31. The method of claim 26, wherein time domain multiplexing further comprises rearranging each subflow within the time domain according to the particular schedule.

32. A method of routing optical data comprising: receiving an incoming optical data stream; segregating the incoming data stream into a plurality of subflows, wherein each subflow is destined for a particular egress port; generating a micro lambda from each subflow by converting each subflow into a parallel data burst across multiple wavelengths wherein each micro lambda contains a subflow's worth of data; wavelength multiplexing each micro lambda; time domain multiplexing each micro lambda; and transmitting each micro lambda to an egress edge unit according to a particular schedule established by a core controller monitoring the incoming optical data stream; and routing at least one micro lambda through a non-destination egress edge unit prior to routing the at least one micro lambda to a destination egress edge unit.

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to telecommunications systems and methods, and more particularly, a non-blocking, scalable optical router having an architecture that routes data from an ingress port to an egress port through a non-blocking switch using time wave division multiplexing (TWDM).

BACKGROUND OF THE INVENTION

The emergence of the Internet and the reliance by business and consumers on the transfer of data in all daily activities requires telecommunications networks and components that can deliver ever increasing amounts of data at faster speeds with higher quality levels. Current telecommunications networks fail to meet these requirements. Currently, data networks are constructed with a variety of switches and routers that are interconnected, typically as a full or partial mesh, in order to attempt to provide connectivity for data transport over a large geographic area.

In order to try to meet the increasing bandwidth requirements in these networks, in very large Internet Protocol (IP) networks, aggregation routers at the fringes of the network will feed large amounts of data to a hierarchy of increasingly large optical cross-connects within a mesh network. These existing switching architectures are limited in the switching speeds and data capacity that can be processed between switches in a non-blocking manner. Current electrical switching architectures are generally limited to a switching speed of 40-100 Gigabits. In an attempt to overcome this limitation, current electrical and optical routers use this aggregation of slower switches to increase the overall switching speed of the router. For example, a system may combine a hundred one (1) Gigabit routers to increase the switching speed of the system. However, while the overall speed and capacity will exceed one Gigabit, this aggregation will not result in full 100 Gigabit per second speed and capacity, resulting in a decreased efficiency (less than full realization of switching capability). Furthermore, aggregation increases costs due to the increased number of routers and increases complexity due to interconnect and routing issues. In addition to the issues surrounding data routing speed, electronic telecommunication routing systems all face difficult transference issues when interfacing with optical data packets. Another technique used in electrical telecommunication routing systems to increase data routing speed is parallel processing. However, this technique has its own limitations including control complexity (it is difficult to control the multiple routers operating in parallel). In any of these techniques involving multiple routers to increase the processing speed, a single control machine must arbitrate among the many multiple machines that increases control complexity, cost and ultimately uses an electronic control machine that is limited by electronic processing speeds.

FIGS. 1 and 2 will illustrate the limitations of these prior art systems. FIG. 1 shows a typical prior art local network cluster 10 that uses an interconnect structure with multiple routers and switches to provide the local geographic area with a bandwidth capability greater than that possible with any one switch in the router 10. Network 10 includes four routers 12, which will be assumed to be 300 Gigabit per second routers, each of which serves a separate area of 150 Gbps of local traffic. Thus, the 300 Gigabit capacity is divided by assigning 150 Gigabits per second (Gbps) to the incoming traffic on local traffic links 16 and assigning 50 Gbps to each of three links 14. Thus, each link 14 connects the router 12 to every other router in the network 10, thereby consuming the other 150 gigabit capacity of the router 12. This interconnectivity is in the form of a balanced "mesh" that allows each router 12 to communicate directly with every other router 12 in the network 10.

This configuration has a number of limitations. While the four local geographic areas produce a total of 600 Gbps of capacity, the network 10 requires four routers 12 of 300 Gbps each, or 1200 Gbps of total router capacity, to provide the interconnectivity required to allow direct communication between all routers 12. Additionally, even though fully connected, each router 12 does not have access to all of the capacity from any other router 12. Thus, only one third of the local traffic (i.e., only 50 Gbps of the total potential 150 Gbps) can be switched directly from any one router 12 to another router 12, and the total potential traffic demand is 600 Gigabits per second. In order to carry more traffic over a link 14, a larger capacity would be required at each router 12 (for example, to carry all 150 Gbps over a link 14 between routers, each link 14 would need to be a 150 Gbps link and each router 12 would have to have an additional 300 Gbps capacity). Thus, to get full connectivity and full capacity, a non-blocking cluster network 10 having a mesh configuration would require routers with 600 Gbps capacity each which equates to 2400 Gbps total router capacity (or four times the combined traffic capacity of the local geographic areas).

FIG. 2 shows another prior art optical cross-connect mesh network 18 that aggregates sixteen data lines 20 that each can carry up to one hundred sixty gigabit per second of data that appears to have the potential capacity of 2.5 Terabits (16 lines carrying 160 Gbps each). Each of the data lines 20 is routed through an edge router 22 to an interconnected edge network 24 (e.g., a ring, mesh, ADM backbone or other known interconnection method) via carrying lines 26. However, due to inefficiencies in this network configuration (as described above), the full potential of 2.5 Terabits cannot be achieved without a tremendous increase in the size of the edge routers 22. For example, if the edge routers are each 320 Gbps routers, then 160 Gbps is used to take incoming data from incoming data line 20 and only 160 Gbps of access remains to send data to each of the other fifteen routers 22 in the cluster 18 (i.e., approximately 10 Gbps can be allotted to each of the other fifteen routers, resulting in greater than 90% blockage of data between routers). Furthermore, the capacity of the routers is already underutilized as the overall router capacity of the network cluster 18 is 5 terabits per second (Tbps), while the data capacity actually being serviced is 2.5 Tbps. Even with the router capacity underutilized, the network 18 has over 90% blockage between interconnected routers through the edge network 24. To increase the capacity between routers in a non-blocking manner, the individual routers would need to be increased in capacity tremendously, which increases cost and further exacerbates the underutilization problems already existing in the network.

FIG. 3 illustrates a typical hierarchy of an example prior art network 11 consisting of smaller routers 23 connected to larger aggregation routers 21 which in turn connect to a connected network 27 of optical cross-connects 25 for transport of IP data in a circuit switched fashion utilizing waves or lambdas (i.e., one lambda per switched circuit path). Even though the larger aggregation routers 21 have high capacity for IP data traffic, these larger aggregation routers 21 require even larger capacity optical cross-connects 25 to establish the connectivity to the other aggregation routers 21 in order to communicate data. The optical cross-connects 25, although extremely large in capacity (e.g., on the order of 10 to 100 times the capacity of the aggregation routers 21), nevertheless require multiple units interconnected as a mesh in order to provide the total capacity needed for the combined data capacity of the aggregation routers 21 taken together. The aggregation routers 21 simply do not have sufficient port capacity to be able to communicate with their peers without the aid of the optical cross-connect mesh network 27 for sufficient transport capacity. In addition, no single optical cross-connect 25 has sufficient capacity to carry all of the aggregation router 21 traffic. Therefore, multiple optical cross-connect units 25 meshed together in a network 27 are required to carry the total aggregation router 21 IP traffic of the network 11 in a distributed fashion.

In addition, network 11 of FIG. 3 suffers from severe blocking because each aggregation router 21 cannot dynamically communicate all of its data at any one time to any of its peer aggregation routers 21 in network 11. Moreover, the optical cross-connect network 27 has a relatively static configuration that can only transport a fraction of any particular aggregation router's 21 data to the other aggregation routers 21 in the network 11. Even though the optical cross-connect network 27 utilizes a large number of high capacity optical cross-connects 25, the cross-connect network 27 has the limitation of a large number of inter-machine trunks that are required between cross-connect units 25 in order for the mesh to have sufficient capacity to support the total data transport requirement of all of the aggregation routers 21. Unfortunately, the inter-machine trunks between the optical cross-connects 25 consume capacity at the expense of ports that could otherwise be used for additional aggregation router 21 capacity. Therefore, the network 11 is a "port-poor" network that is generally inefficient, costly, and unable to accommodate the dynamic bandwidth and connectivity requirements of an ever changing, high capacity IP network.

Therefore, a need exists for an optical telecommunications network and switching architecture that will provide full, non-blocking routing between edge routers in a network on a port-to-port (i.e., ingress port to egress port) basis and controlled at the input (ingress) side of the routing network.

SUMMARY OF THE INVENTION

The present invention provides a non-blocking optical routing system and method that substantially eliminates or reduces disadvantages and problems associated with previously developed optical routing systems and methods.

More specifically, the present invention provides a system and method for providing non-blocking routing of optical data through a telecommunications network on a port-to-port basis to maximize utilization of available capacity while reducing routing complexity. The network includes a number of data links that carry optical data to and from an optical router. The optical router includes a number of ingress edge units coupled to an optical switch core coupled further to a number of egress edge units. The ingress edge units receive the optical data from the data links and convert the optical data into ".mu..lamda.s" where each .mu..lamda. is to be routed to a particular destination egress edge port. The .mu..mu.s are sent from the ingress edge units to an optical switch fabric within the optical switch core that routes each .mu..lamda. through the optical switch fabric to the .mu..lamda.'s particular destination egress edge unit in a non-blocking manner (i.e., without contention or data loss through the optical switch fabric). This routing is managed by a core controller that monitors the