PORT-TO-PORT, NON-BLOCKING, SCALABLE OPTICAL ROUTER ARCHITECTURE AND METHOD FOR ROUTING OPTICAL TRAFFIC

• US 20090074414A1
• Filed: 09/15/2008
• Published: 03/19/2009
• Est. Priority Date: 04/03/2001
• Status: Active Grant

• Current Assignee: Mind Fusion, LLC (Ascend Innovation Management, LLC)
• Original Assignee: Yotta Networks, Inc.
• Inventors: Posey, Noland J. JR., Tamil, Lakshman S., Rothrock, Scott A., Miles, Larry L., Aicklen, Gregory H.
• Granted Patent: US 7,773,608 B2
• Time in Patent Office: Days
• US Class Current: 398/75
• CPC Class Codes: H04J 14/0223 Conversion to or from optical TDM
• 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: H04L 45/62 Wavelength based optical switching H04Q11/0062
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/005 Arbitration and scheduling
• CPC Class Codes: H04Q 2011/0084 Quality of service aspects

Abstract

Embodiments of the present invention provide an optical network and switch architecture that provides non-blocking routing from an ingress router to an egress router in the network on a port-to-port basis. The present invention provides routing for fixed and variable length optical data packets of varying types (including Internet Protocol (IP), data, voice, TDM, ATM, voice over data, etc.) at speeds from sub-Terabit per second (Tbps), to significantly in excess of Petabit per second (Pbps). The present invention includes the functionality of both large IP routers and optical cross-connects combined with a unique, non-blocking optical switching and routing techniques to obtain benefits in speed and interconnected capacity in a data transport network. The present invention can utilize a TWDM wave slot transport scheme in conjunction with a just-in-time scheduling pattern and a unique optical switch configuration that provides for non-blocking transport of data from ingress to egress.

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, each micro lambda containing data destined for a particular egress edge port. 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. The router can also include a core controller that receives scheduling information from the plurality of ingress edge units and egress edge units. Based on the scheduling information, the core controller can develop a schedule pattern (i.e., a TWDM cycle) to coordinate the time domain multiplexing of micro lambdas at the plurality of ingress edge units and non-blocking switching of the micro lambdas at the switch fabric.

Claims

1. A router, 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 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;

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

transmits each micro lambda at the corresponding ingress edge unit to the switch fabric according to the schedule pattern;

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.

2. The router of claim 1, wherein each ingress edge unit time wavelength division multiplexes 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.

3. The router of claim 2, further comprising:

an optical switch fabric in communication with the plurality of ingress edge units and egress edge units that receives the plurality of micro lambdas from the plurality of ingress edge units and routes 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; and

wherein the core controller that establishes 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.

4. 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 segregates 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, time multiplexes each subflow, converts each subflow into a micro lambda, wavelength multiplexes each micro lambda and transmits each micro lambda in a particular wave slot;

wherein the egress edge unit receives each micro lambda from the ingress edge unit, time and wavelength demultiplexes each micro lambda, converts each micro lambda back into the corresponding subflow, and outputs the subflows as a continuous data stream, and

wherein the 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;

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

transmits each micro lambda at the corresponding ingress edge unit to the switch fabric according to the schedule pattern.

5. The router of claim 4, further comprising:

a switch fabric that receives each micro lambda from the ingress edge unit and routes each micro lambda to the egress edge unit in a non-blocking manner; and

a core controller that controls 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.