Dynamically assignable optical signal access control apparatus

• US 6,535,313 B1
• Filed: 10/16/1998
• Issued: 03/18/2003
• Est. Priority Date: 10/16/1998
• Status: Expired due to Term

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Sohraby, Kazem Anaraky, Fatehi, Mohammad Taghi
• Primary Examiner(s): Pascal, Leslie
• Assistant Examiner(s): Sedighian, M. R.
• Application Number:
  US09/173,793
• Time in Patent Office: 1,614 Days
• Field of Search: 359/117, 359/139, 359/123, 359/124, 359/128, 370/230, 370/412, 370/413, 370/428, 370/429
• US Class Current: 398/101
• 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: H04J 14/0241 Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths
• CPC Class Codes: H04J 14/0284 WDM mesh architectures

Abstract

An optical signal access apparatus responds to variations in network traffic by dynamically assigning the number of wavelengths at originating and terminating optical signal access apparatus. A controller of an optical signal access apparatus monitors network traffic by checking the occupancy level (or other parameters) of data buffers and determines therefrom the number of optical signals that should be allocated to handle the network traffic from those buffers. When the optical signal access apparatus is part of a router it can be used to control traffic at the router as well as on the links between the routers of an optical network.

Claims

1. An optical signal access apparatus comprising

a data buffer for storing received electrical data packets and for outputting electrical data packets the data using any of a variety of protocols;

a plurality of optical signal modulators, each for modulating a different optical signal using the outputted data packets from the buffer;

a switch, responsive to a control signal for switchably connecting the outputted data packets to one or more of the plurality optical signal modulators; and

a controller for checking a data packet occupancy level of the buffer and, in response thereto, sending said control signal to the switch indicating a number of the plurality optical signal modulators to be assigned to receive the outputted data packets from the data buffer;

the optical signal access apparatus being part of an optical router including

an optical switch having a plurality of inputs for receiving modulated optical signals from the optical modulators and for switchable connecting than to a plurality of outputs;

a plurality of wavelength interchangers connected to the outputs of the optical switch, each wavelength interchanger for changing a received optical signal to a selected one of a group of wavelengths in response to a control signal from the controller; and

an optical multiplexer for multiplexing together the selected wavelengths outputted from the interchangers into a wavelength division multiplexed (WDM) optical signal.

2. The optical signal access apparatus of claim 1 wherein the controller checks the data packet occupancy level every τ

seconds and sends control signals to the switch every T seconds, where T is ≧

τ

.

3. The optical signal access apparatus of claim 1 being part of an optical network including

a plurality of said routers and

a centralized network control management apparatus for communicating signals for controlling the controllers of said routers.

4. The network of claim 1 wherein the router connects to at least one optical link for receiving and transmitting WDM optical signals thereover and wherein

the controller also controls the assignment of wavelengths over the at least one optical link.

5. The optical signal access apparatus of claim 1 being part of an optical router and wherein

the optical modulators are wavelength selectable lasers having wavelengths that are selected in response to a control signal from the controller and

wherein the optical router includes

an optical multiplexer for multiplexing together the selected wavelengths outputted from the wavelength selectable lasers into a wavelength division multiplexed (WDM) optical signal.

6. The router of claim 5 being part of an optical network including

a plurality of said routers and

a centralized network control management apparatus for communicating signals for controlling the controllers of said routers.

7. The router of claim 5 wherein the router connects to at least one optical link for receiving and transmitting WDM optical signals thereover and wherein

the controller also controls the assignment of wavelengths over the at least one optical link.

8. The optical signal access apparatus of claim 1 wherein the optical modulators are light emitting diodes.

9. The optical signal access apparatus of claim 1 wherein the optical modulators are lasers.

10. The optical signal access apparatus of claim 1 wherein the controller is also responsive to a received network control management signal for generating the control signal.

11. An optical signal access apparatus comprising

an optical signal modulator apparatus including

a data buffer for storing received electrical data packets and for outputting electrical data packets, the data packets using any of a variety of protocols;

a plurality of optical signal modulators, each for modulating a different optical signal using the outputted data packets from the buffer,

a switch, responsive to a control signal, for switchably connecting the outputted data packets to one or more of the plurality optical signal modulators; and

a controller for checking a data pat occupancy level of the buffer and, in response thereto, sending said control signal to the switch indicating a number of the plurality optical signal modulators to be assigned to receive the outputted data packets from the data buffer; and

an optical signal demodulator apparatus including

a plurality of optical signal demodulators, each for demodulating a different received optical signal into electrical data packets;

a second switch, responsive to a second control signal, for switchably connecting electrical data packets outputted from one or more of the plurality of optical signal demodulators to a second data buffer;

the second data buffer used for storing received electrical data packets and for outputting electrical data packets; and

a second controller responsive to a received third control signal for sending said second control signal to the second switch indicating the number of optical signal demodulators to be connected to the second data buffer.

12. The optical signal access apparatus of claim 11 wherein the switch and the second switch are part of a combined switch, the buffer and the second buffer are part of a combined buffer, the controller and the second controller are part of a combined controller.

13. The optical signal access apparatus of claim 11 being part of an optical router including

an optical demultiplexer for demultiplexing a received wavelength division multiplexed (WDM) optical signal into said different received optical signals for said plurality of optical signal demodulators.

14. The optical signal access apparatus of claim 11 being part of an optical router including

an optical demultiplexer for demultiplexing a received wavelength division multiplexed (WDM) optical signal into a plurality of optical signals;

an optical switch for receiving said plurality of optical signals from the optical demultiplexer and for switchable connecting them to said plurality of optical signal demodulators.

15. A method of operating an optical router comprising the steps of

storing at a data buffer, received electrical data packets having any of a variety of protocols and outputting electrical data packets;

switchably connecting through an electrical switch, the outputted data packets to one or more of the plurality optical signal modulators;

modulating at the one or more of the plurality optical signal modulators, a number of different optical signals using selected ones of the outputted data packets;

checking at a controller, a data packet occupancy level of the buffer and, in response thereto, sending a control signal to the electrical switch indicating a number of the plurality of optical signal modulators to be assigned to receive the outputted data packets from the data buffer;

receiving at an optical switch, modulated optical signals from the optical modulators and switchably connecting them to a plurality of outputs;

at a plurality of wavelength interchangers connected to the outputs of the optical switch, changing an optical signal received from an output of the optical switch to a selected one of a group of wavelengths in response to a control signal from the controller; and

optically multiplexing together the selected wavelengths outputted from the interchangers into a wavelength division multiplexed (WDM) optical signal.