Method and system for multiplexed optical information transport

• US 20020196499A1
• Filed: 06/21/2002
• Published: 12/26/2002
• Est. Priority Date: 06/25/2001
• Status: Active Grant

• Current Assignee: Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Original Assignee: Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Inventors: Wellen, Jeroen
• Granted Patent: US 7,676,156 B2
• Time in Patent Office: Days
• US Class Current: 398/98
• CPC Class Codes: H04J 14/0226 Fixed carrier allocation, e.g. according to service
• 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 14/0246 using one wavelength per ONU
• CPC Class Codes: H04J 14/025 using one wavelength per ONU, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU
• CPC Class Codes: H04J 14/0282 WDM tree architectures
• CPC Class Codes: H04M 15/00 Arrangements for metering, time-control or time indication ; Metering, charging or billing arrangements for voice wireline or wireless communications, e.g. VoIP
• CPC Class Codes: H04M 15/47 Fraud detection or prevention means
• CPC Class Codes: H04M 2215/0148 Fraud detection or prevention means

Abstract

Light carrying information for access terminals is carried via optical fibers. Information for terminals from groups is multiplexed over different time-slots and different communication wavelengths of the light in the fiber for a group. The information is passed between the fibers and the transport network via transceivers. The use of the transceivers is multiplexed between the optical fibers. Each transceiver passes information for selectable light guides at selectable communication wavelengths in different timeslots.

Claims

1. A method of multiplexing optical information transport between a plurality of access terminals and a transport network, the method comprising:

transporting light carrying information for respective groups of access terminals each via a respective light guide, the information for different terminals in each group being multiplexed over different time slots and different communication wavelengths of the light in the light guide for that group;

passing the information between the light guides and the transport network via transceivers that include a transmitter for passing information from the transport network to the light guides and/or a transmitter for passing information from the light guides to the transport network; and

multiplexing use of the transceivers, wherein each transceiver passes information for selectable light guides at selectable communication wavelengths in different time slots.

2. A method according to claim 1, further comprising:

dynamically cross-connecting the light guides to respective cross-connect input/outputs each corresponding to a respective one of the transceivers; and

dynamically selecting a respective communications wavelength for each transceiver and filtering out light components at other wavelengths than the selected wavelength from light passed between the transceiver and its corresponding input/output.

3. A method according to claim 1, wherein the number of transceivers used is less than the number of light guides used.

4. A communications network comprising:

a transport network;

a plurality of access terminals;

a plurality of light guides, each coupling a respective group of the access terminals to the transport network, different access terminals in each group being capable of sending and/or receiving information to and/or from the transport network carried by light of different communication wavelengths respectively;

a plurality of transceivers between the light guides and the transport network, each transceiver comprising a transmitter for passing information from the transport network to the light guides and/or a transmitter for passing information from the light guides to the transport network;

a cross-connection unit between the light guides and the transceivers, arranged to make selectable active couplings for light transport between each light guide and a respective selectable combination of the transceivers, simultaneously active couplings between any one of the light guides and different ones of the transceivers being allowed, the coupling between that one of the light guides to each actively coupled transceiver being at a respective selectable communication wavelength; and

a control unit for dynamically activating the couplings selectively on the basis of transport capacity requirements of the access terminals.

5. A communications network according to claim 4, wherein the cross-connection unit comprises:

a sub-unit arranged to make selectable active couplings for light transport between each light guide and a respective selectable combination of connections, each coupling passing all communication wavelengths, each connection being provided for a corresponding one of the transceivers; and

a respective filter between each connection and the corresponding one of the transceivers respectively, the respective filter passing a communications wavelength selectable by the control circuit.

6. A communications network according to claim 4, wherein at least one of the transceivers comprises a transceiver and wherein the cross-connection unit comprises for that at least one of the transceivers:

a sub-unit arranged to make selectable active couplings for light transport between each light guide and a respective selectable combination of connections, each coupling passing all communication wavelengths, each connection being provided for a corresponding one of the transceivers;

a wavelength multiplexing unit, with a multiplexed connection coupled to one of the connections of the sub-unit and demultiplexed connections for individual ones of the communications wavelengths;

light sources for respective ones of the wavelengths;

optical switches controlled each between a respective one of the light sources and a respective one of the demultiplexed connections by the selection of the wavelength for the at least one of the transceivers and the information that is passed to the access terminals by the transceiver.

7. A communications network according to claim 4, wherein the cross-connection unit comprises:

respective first wavelength multiplexing units, each with a multiplexed connection coupled to a respective one of the light guides and demultiplexed connections for individual ones of the communications wavelengths;

respective second wavelength multiplexing units, each with a multiplexed connection coupled to a respective one of the transceivers and demultiplexed connections for individual ones of the communications wavelengths;

a plurality of sub-cross-connection units, each coupling the demultiplexed connections of the first and second multiplexing units for a respective one of the communications wavelengths.

8. A communications network according to claim 4, wherein a number L of the transceivers exclusively receives information from a number N of the light guides, the N liqht guides exclusively passing light to the L transceivers, wherein L is less than N.

9. A communications network according to claim 4, wherein the transceivers are arranged for transporting information received from the access terminals to the transport network only, the communications network comprising:

further transceivers connected to the transport network, for passing information from the transport network to the access terminals only;

a further cross-connection unit between the light guides and further transceivers, arranged to make selectable active couplings for light transport from each transceiver to a respective selectable one of the light guides.

10. A communications network according to claim 9, the active couplings from the further transceiver to the combination of light guides being at a respective selectable communication wavelengths.