US 7,209,657 B1Granted

Optical routing using a star switching fabric

AssigneeCheetah Omni, LLC

InventorMohammed N. Islam

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Abstract

In one embodiment, a router includes a plurality of line cards each operable to receive at least one packet comprising an identifier associated with a destination element external to the router. Each line card includes a look-up table operable to facilitate routing the received packet toward the destination element based at least in part on the identifier. The router further includes a plurality of optical transmitters each associated with one of the line cards and operable to generate at a specified wavelength an optical router signal comprising at least a portion of the packet received by the line card associated with that optical transmitter. The router also includes a star switching fabric operable to receive a plurality of optical router signals from the plurality of optical transmitters and to communicate to each of a plurality of tunable filters a substantially similar set of at least some of the plurality of optical router signals. Each of the plurality of tunable filters is operable to selectively tune to a wavelength of one of the plurality of optical router signals to facilitate communication of the packet associated with that optical router signal toward the destination element.

Claims88

Dependent claims

A communication system comprising:

one or more line cards each operable to receive at least one packet comprising an identifier associated with at least one of a plurality of destination elements, each line card comprising control circuitry operable to generate a control signal comprising control information;
one or more optical transmitters each associated with one of the one or more line cards and each operable to generate at a specified wavelength an optical signal comprising at least a portion of the at least one packet received by the line card associated with that optical transmitter, the optical signal further comprising at least a portion of the control information of the control signal generated by the control circuitry of the line card associated with that optical transmitter;
and
a receiver associated with one of the one or more line cards and operable to receive an upstream optical signal from the plurality of destination elements;
a communicating fabric operable to receive the optical signals from the one or more optical transmitters and to communicate to each of the plurality of destination elements at least some of the optical signals, wherein the at least a portion of the control information of the optical signal is communicated to the plurality of destination elements through the communicating fabric in a same direction as the optical signals;
wherein each of the plurality of destination elements comprise a filter coupled to a destination receiver and a destination transmitter, the destination receiver operable to receive at least a fraction of the optical signals, the destination elements operable to, based at least in part on the control information of the optical signal, perform an operation to generate the upstream optical signal that is transmitted by the destination transmitter, the destination elements coupled to the communicating fabric, which communicates at least a fraction of the upstream optical signal to the receiver associated with the one of the line cards;
wherein at least some of the one or more optical transmitters comprise a modulator operable to receive from a super-continuum source an unmodulated optical signal having a center wavelength and to modulate the received signal, wherein the super-continuum source is operable to generate using a single optical source a plurality of unmodulated optical signals each having a center wavelength, and wherein the super-continuum source comprises:
a pulse source operable to generate a plurality of optical pulses;
a continuum generator operable to broaden the spectrum of the plurality of optical pulses into an approximate spectral continuum of optical pulses;
and
a signal splitter operable to generate from the approximate continuum the plurality of unmodulated optical signals each comprising a center wavelength.

8 more elements

A line card for use in a communication system and operable to receive a packet comprising an identifier associated with a destination element, the line card comprising:

a control circuitry operable to facilitate generation of a control signal comprising control information based at least in part on the identifier;
an optical transmitter operable to generate an optical signal comprising at least a portion of the packet, the optical signal further comprising at least a portion of the control information of the control signal at a particular wavelength, the optical transmitter further operable to communicate the optical signal to a communicating fabric;
an optical receiver operable to receive an upstream optical signal, wherein the at least a portion of the control information of the optical signal is communicated to the destination element through the communicating fabric in a same direction as the optical signals;
and
wherein the destination element comprises a filter coupled to a destination receiver and a destination transmitter, the filter operable to receive at least a portion of the optical signals from the communicating fabric;
the destination receiver operable to receive at least a fraction of the optical signals, the destination elements operable to, based at least in part on the control information of the optical signal, perform an operation to generate the upstream optical signal that is transmitted by the destination transmitter, the destination elements coupled to the communicating fabric, which communicates at least a fraction of the upstream optical signal to the receiver associated with the one of the line cards;
wherein the optical transmitter comprises a modulator operable to receive from a super-continuum source an unmodulated optical signal having a center wavelength and to modulate the received signal, wherein the super-continuum source is operable to generate using a single optical source a plurality of unmodulated optical signals each having a center wavelength, and wherein the super-continuum source comprises:
a pulse source operable to generate a plurality of optical pulses;
a continuum generator operable to broaden the spectrum of the plurality of optical pulses into an approximate spectral continuum of optical pulses;
and
a signal splitter operable to generate from the approximate continuum the plurality of unmodulated optical signals each comprising a center wavelength.

8 more elements

A communication system comprising:

a first plurality of line cards residing in a first location;
a second plurality of line cards residing in one or more other locations physically separate from the first location, wherein each of the line cards of the first and second pluralities of line cards comprises a filter coupled to a receiver and an optical transmitter operable to transmit at a specified wavelength an optical signal;
a communicating fabric operable to receive a plurality of optical signals from the optical transmitters and to communicate sets of optical signals to each of a plurality of filters, wherein at least some of the optical signals comprise at least a portion of at least one packet received by one of the plurality of first line cards;
wherein the communicating fabric operates as an interconnect between the different locations of line cards and wherein the communication system is operable to communicate an optical signal from an optical transmitter residing in the first location to a filter residing in the one or more other locations without converting the optical signal to an electronic form between the optical transmitter and the filter;
and
wherein the first plurality of line cards further comprise a control circuitry operable to generate a control signal comprising control information, and wherein the optical transmitters associated with the first plurality of line cards communicate the control information of the control signal as at least a part of the optical signal to the second plurality of line cards, and wherein the second plurality of line cards perform a function based at least in part on the control information of the control signal received, wherein the at least a portion of the control information of the optical signal is communicated to each of the second plurality of line cards through the communicating fabric in a same direction as the optical signals;
wherein the optical transmitters associated with the first plurality of line cards comprise a modulator operable to receive from a super-continuum source an unmodulated optical signal having a center wavelength and to modulate the received signal, wherein the super-continuum source is operable to generate using a single optical source a plurality of unmodulated optical signals each having a center wavelength and wherein the super-continuum source comprises:
a pulse source operable to generate a plurality of optical pulses;
a continuum generator operable to broaden the spectrum of the plurality of optical pulses into an approximate spectral continuum of optical pulses;
and
a signal splitter operable to generate from the approximate continuum the plurality of unmodulated optical signals each comprising a center wavelength.

8 more elements

A communication network comprising:

one or more line cards each operable to receive at least one packet comprising an identifier associated with at least one of a plurality of destination;
one or more control circuitry each associated with one of the line cards and operable to generate a control signal comprising control information;
one or more optical transmitters each associated with one of the line cards and each operable to generate at a specified wavelength an optical signal comprising at least a portion of the packet received by the associated the line card, the optical signal further comprising at least a portion of the control information of the control signal;
one or more optical receivers each associated with one of the line cards and operable to receive an upstream optical signal from the one or more destination elements;
a communicating fabric operable to receive one or more optical signals from at least some of the one or more optical transmitters and to communicate sets of optical signals to at least some of the plurality of destination elements, wherein the at least a portion of the control information of the optical signal is communicated to the at least some of the plurality of destination elements through the communicating fabric in a same direction as the optical signals;
wherein each of the plurality of destination elements comprises a filter coupled to a destination receiver and a destination transmitter, the destination receiver operable to receive at least a fraction of the optical signals, the destination elements operable to, based at least in part on the control information of the optical signal, perform an operation to generate the upstream optical signal that is transmitted by the destination transmitter, the destination elements coupled to the communicating fabric, which communicates at least a fraction of the upstream optical signal to the receiver associated with the one of the line cards;
wherein at least some of the one or more optical transmitters comprise a modulator operable to receive from a super-continuum source an unmodulated optical signal having a center wavelength and to modulate the received signal, wherein the super-continuum source is operable to generate using a single optical source a plurality of unmodulated optical signals each having a center wavelength, and wherein the super-continuum source comprises:
a pulse source operable to generate a plurality of optical pulses;
a continuum generator operable to broaden the spectrum of the plurality of optical pulses into an approximate spectral continuum of optical pulses;
and
a signal splitter operable to generate from the approximate continuum the plurality of unmodulated optical signals each comprising a center wavelength.

8 more elements

A communicating core for use in a communication system, the communicating core comprising:

a communicating fabric operable to receive a plurality of input optical signals, at least some optical signals comprising a packet associated with a destination element and at least a portion of control information of a control signal generated by a control circuitry, wherein the communicating fabric is operable to generate a plurality of output optical signals each comprising at least some of the plurality of input optical signals;
and
a plurality of destination elements coupled to the communicating fabric, wherein the at least a portion of the control information of the optical signal is communicated to the plurality of destination elements through the communicating fabric in a same direction as the optical signals,
wherein each of the plurality of destination elements comprises a filter coupled to a destination receiver and a destination transmitter, the destination receiver operable to receive at least a fraction of the optical signals, the destination elements operable to, based at least in part on the control information of the optical signal, perform an operation to generate the upstream optical signal that is transmitted by the destination transmitter, the destination elements coupled to the communicating fabric, which communicates at least a fraction of the upstream optical signal to the receiver associated with the one of the line cards;
wherein at least some of the plurality of input optical signals is generated from a communication transmitter comprising a modulator operable to receive from a super-continuum source an unmodulated optical signal having a center wavelength and to modulate the received signal, wherein the super-continuum source is operable to generate using a single optical source a plurality of unmodulated optical signals each having a center wavelength, and wherein the super-continuum source comprises:
a pulse source operable to generate a plurality of optical pulses;
a continuum generator operable to broaden the spectrum of the plurality of optical pulses into an approximate spectral continuum of optical pulses;
and
a signal splitter operable to generate from the approximate continuum the plurality of unmodulated optical signals each comprising a center wavelength.

6 more elements

A communication system, comprising:

one or more line cards each operable to receive at least one Internet Protocol (IP) or Transmission Control Protocol (TCP) or Multiple Protocol Label Switching (MPLS) or Generalized Multiple Protocol Label Switching (GMPLS) packet, each line card operable to perform header or label processing to facilitate communicating the received packet toward one or more destination elements, and each line card further comprising a control circuitry capable of generating a control signal comprising control information;
one or more optical transmitters each associated with one of the line cards and each operable to generate at a particular wavelength an optical signal comprising at least a portion of the packet received by the line card associated with that optical transmitter, the optical signal further comprising at least a portion of the control information of the control signal generated by the control circuitry;
and
a communicating fabric operable to receive one or more optical signals from the one or more optical transmitters and to communicate a set of optical signals to each of one or more destination elements, wherein the at least a portion of the control information of the optical signal is communicated to the one or more destination elements through the communicating fabric in a same direction as the optical signals,
wherein each of the one or more destination elements comprises a filter coupled to a destination receiver and a destination transmitter, the destination receiver operable to receive at least a fraction of the optical signals, the destination elements operable to, based at least in part on the control information of the optical signal, perform an operation to generate the upstream optical signal that is transmitted by the destination transmitter, the destination elements coupled to the communicating fabric, which communicates at least a fraction of the upstream optical signal to the destination receiver;
wherein at least some of the one or more optical transmitters comprise a modulator operable to receive from a super-continuum source an unmodulated optical signal having a center wavelength and to modulate the received signal, wherein the super-continuum source is operable to generate using a single optical source a plurality of unmodulated optical signals each having a center wavelength, and wherein the super-continuum source comprises:
a pulse source operable to generate a plurality of optical pulses;
a continuum generator operable to broaden the spectrum of the plurality of optical pulses into an approximate spectral continuum of optical pulses;
and
a signal splitter operable to generate from the approximate continuum the plurality of unmodulated optical signals each comprising a center wavelength.

7 more elements

In a communication system comprising one or more line cards coupled to a communicating fabric, a method of communicating optical signals, comprising:

receiving at a first line card a first packet comprising an identifier;
using a control circuitry on the first line card to determine a control signal comprising control information;
generating an optical signal at the first line card, the optical signal comprising at least a portion of the first packet received by the first line card, the optical signal further comprising at least a portion of the control information of the control signal;
communicating the first packet and the control information of the control signal to the communicating fabric in an optical format having a first wavelength;
communicating from the communicating fabric to a plurality of destination elements each associated with a separate output link from the communication system the first packet and the control information of the optical signal, wherein the at least a portion of the control information of the optical signal is communicated to the plurality of destination elements through the communicating fabric in a same direction as the optical signals;
wherein each of the plurality of destination elements comprises a filter coupled to a destination receiver and a destination transmitter, the destination receiver operable to receive at least a fraction of the optical signals, the destination element operable to, based at least in part on the control information of the optical signal, perform an operation to generate the upstream optical signal that is transmitted by the destination transmitter, the destination elements coupled to the communicating fabric, which communicates at least a fraction of the upstream optical signal to the receiver associated with the one of the line cards;
wherein the optical signal is generated by a communication transmitter comprising a modulator operable to receive from a super-continuum source an unmodulated optical signal having a center wavelength and to modulate the received signal, wherein the super-continuum source is operable to generate using a single optical source a plurality of unmodulated optical signals each having a center wavelength and wherein the super-continuum source comprises:
a pulse source operable to generate a plurality of optical pulses;
a continuum generator operable to broaden the spectrum of the plurality of optical pulses into an approximate spectral continuum of optical pulses;
and
a signal splitter operable to generate from the approximate continuum the plurality of unmodulated optical signals each comprising a center wavelength.

8 more elements

A communication system comprising:

one or more line cards each operable to receive at least one packet comprising an identifier associated with at least one of a plurality of destination elements, each line card comprising control circuitry operable to generate a control signal comprising control information;
one or more optical transmitters each associated with one of the one or more line cards and each operable to generate at a specified wavelength an optical signal comprising at least a portion of the at least one packet received by the line card associated with that optical transmitter, the optical signal further comprising at least a portion of the control information of the control signal generated by the control circuitry of the line card associated with that optical transmitter;
and
a receiver associated with one of the one or more line cards and operable to receive an upstream optical signal from the plurality of destination elements;
a communicating fabric operable to receive the optical signals from the one or more optical transmitters and to communicate to each of the plurality of destination elements at least some of the optical signals, wherein the at least a portion of the control information of the optical signal is communicated to the plurality of destination elements through the communicating fabric in a same direction as the optical signals;
wherein each of the plurality of destination elements comprises a destination receiver and an upstream signal generator, the destination receiver operable to receive at least a fraction of the optical signals, the destination elements operable to, based at least in part on the control information of the optical signal, perform an operation to generate the upstream optical signal that is transmitted by the upstream signal generator, the destination elements coupled to the communicating fabric, which communicates at least a fraction of the upstream optical signal to the receiver associated with the one of the line cards;
wherein at least some of the one or more optical transmitters comprise a modulator operable to receive from a super-continuum source an unmodulated optical signal having a center wavelength and to modulate the received signal, wherein the super-continuum source is operable to generate using a single optical source a plurality of unmodulated optical signals each having a center wavelength, and wherein the super-continuum source comprises:
a pulse source operable to generate a plurality of optical pulses;
a continuum generator operable to broaden the spectrum of the plurality of optical pulses into an approximate spectral continuum of optical pulses;
and
a signal splitter operable to generate from the approximate continuum the plurality of unmodulated optical signals each comprising a center wavelength.

8 more elements

Dependencies are inferred from the claim text.