Optical WDM transmission system having a distributed arrangement of regenerators

Abstract

A network node is provided for use in a WDM optical transmission system that includes a plurality of network nodes interconnected by communication links. The network node includes an optical switch having at least one input port for receiving from the transmission system a WDM signal having a plurality of wavelength components. The network node also includes a regenerator arrangement having sufficient regeneration capacity to regenerate a prescribed fraction of the plurality of wavelength components. The prescribed fraction is less than a maximum number of wavelength components that may be received by the node. A network management element is provided so that the network node can for communicate with a network management center in the transmission system.

1 . In a WDM optical transmission system that includes a plurality of network nodes interconnected by communication links, a network node, comprising: 
 an optical switch having at least one input port for receiving from the transmission system a WDM signal having a plurality of wavelength components;    a regenerator arrangement having sufficient regeneration capacity to regenerate a prescribed fraction of the plurality of wavelength components, said prescribed fraction being less than a maximum number of wavelength components receivable by said node;    a network management element for communicating with a network management center in the transmission system.    
     
     
         2 . The network node of  claim 1  wherein said regenerator arrangement comprises at least one user interface coupled to a local port of the optical switch for conveying traffic between the transmission system and a source of traffic external to the transmission system.  
     
     
         3 . The network node of  claim 1  wherein said prescribed fraction of the plurality of wavelength components is a fixed percentage of said maximum number of wavelength components receivable by said node.  
     
     
         4 . The network node of  claim 1  wherein said prescribed fraction of the plurality of wavelength components is a variable percentage of said maximum number of wavelength components receivable by said node.  
     
     
         5 . The network node of  claim 1  wherein said regenerator arrangement is configured to perform 3R regeneration.  
     
     
         6 . The network node of  claim 1  wherein said regenerator arrangement is configured to perform 2R regeneration.  
     
     
         7 . The network node of  claim 1  wherein said regenerator arrangement is configured to perform 1R regeneration.  
     
     
         8 . The network node of  claim 1  wherein said regenerator arrangement is configured to perform regeneration and wavelength conversion.  
     
     
         9 . The network node of  claim 1  wherein said regenerator arrangement is configured to perform regeneration without wavelength conversion.  
     
     
         10 . The network node of  claim 1  wherein said regenerator arrangement is configured to perform amplification dispersion compensation.  
     
     
         11 . The network node of  claim 1  wherein said regenerator arrangement is configured to perform PMD compensation.  
     
     
         12 . The network node of  claim 1  wherein said optical switch is an optical add/drop multiplexer.  
     
     
         13 . The network node of  claim 1  wherein said optical switch is an optical cross-connect.  
     
     
         14 . The network node of  claim 1  wherein said optical switch is a reconfigurable optical switch.  
     
     
         15 . The network node of  claim 14  wherein said reconfigurable optical switch is an all-optical reconfigurable optical switch.  
     
     
         16 . The network node of  claim 2  wherein said user interface includes at least one transmitter/receiver interface for communicating with the external source of traffic and for performing regeneration when otherwise in an idle mode of operation.  
     
     
         17 . The network node of  claim 15  wherein said transmitter/receiver interface is a short-reach transmitter/receiver interface.  
     
     
         18 . The network node of  claim 2  wherein said at least one user interface comprises a plurality of user interfaces.  
     
     
         19 . The network node of  claim 18  wherein said plurality of user interfaces each includes at least one transmitter/receiver interface for communicating with the external source of traffic and for performing regeneration when otherwise in an idle mode of operation.  
     
     
         20 . The network node of  claim 19  wherein said optical switch is a reconfigurable optical switch.  
     
     
         21 . The network node of  claim 1  wherein said regenerator arrangement comprises at least one dedicated regenerator coupled to a local port of the optical switch.  
     
     
         22 . A method of regenerating at least one wavelength component of a WDM optical signal; 
 receiving the optical signal at a network node;    determining if one or more of the plurality of wavelength components require regeneration;    directing said one or more of the plurality of wavelength components requiring regeneration to a regenerator and directing remaining ones of the plurality of wavelength components to one or more output ports of the network node without undergoing regeneration; and    regenerating said one or more of the plurality of wavelength components requiring regeneration and directing same to one or more output ports of the optical node.    
     
     
         23 . The method of  claim 22  wherein said regenerator is a user interface for conveying traffic between the transmission system and a source of traffic external to the transmission system, said user interface being in an idle mode of operation.  
     
     
         24 . The method of  claim 22  wherein said optical node includes an optical switch having a plurality of local ports and a plurality of user interfaces respectively coupled to the local ports, and wherein the step of directing said one or more of the plurality of wavelength components requiring regeneration to a regenerator includes the step of directing said one or more of the plurality of wavelength components requiring regeneration to one of the plurality of user interfaces, said one user interface being operationally idle when performing the step of regeneration.  
     
     
         25 . The method of  claim 22  wherein the regenerating step includes the step of performing 3R regeneration.  
     
     
         26 . The method of  claim 22  wherein the regenerating step includes the step of performing 2R regeneration.  
     
     
         27 . The method of  claim 22  wherein the regenerating step includes the step of performing 1R regeneration.  
     
     
         28 . The method of  claim 22  further comprising the step of performing wavelength conversion on wavelength components undergoing regeneration.  
     
     
         29 . The method of  claim 22  further comprising the step of performing amplification dispersion compensation.  
     
     
         30 . The method of  claim 22  further comprising the step of performing PMD compensation.  
     
     
         31 . The method of  claim 22  wherein the directing step is performed by an optical add/drop multiplexer.  
     
     
         32 . The method of  claim 22  wherein the directing step is performed by an optical cross-connect.  
     
     
         33 . The method of  claim 22  wherein the directing step is performed by a reconfigurable optical switch.  
     
     
         34 . The method of  claim 23  wherein said user interface includes at least one transmitter/receiver interface for communicating with the external source of traffic and for performing regeneration when otherwise in an idle mode of operation.  
     
     
         35 . The method of  claim 34  wherein said transmitter/receiver interface is a short-reach transmitter/receiver interface.  
     
     
         36 . The method of  claim 22  wherein said regenerator comprises at least one dedicated regenerator.  
     
     
         37 . The method of  claim 24  further comprising the step of performing wavelength conversion on wavelength components undergoing regeneration in an idle user interface assigned a wavelength different from said wavelength components.  
     
     
         38 . The method of  claim 22  wherein the step of determining if one or more of the plurality of wavelengths require regeneration is based on network-wide traffic patterns.  
     
     
         39 . The method of  claim 22  wherein the step of determining if one or more of the plurality of wavelengths require regeneration includes the step of monitoring each wavelength component received at the network node to assess their need for regeneration and the regenerating step includes the step of regenerating a prescribed number of wavelengths most in need of regeneration.  
     
     
         40 . A WDM optical transmission system, comprising: 
 a plurality of network nodes;    at least one optical communication link interconnecting said network nodes, each of said a network nodes including: 
 an optical switch having at least one input port for receiving from the transmission system a WDM signal having a plurality of wavelength components;  
 a regenerator arrangement having sufficient regeneration capacity to regenerate a prescribed fraction of the plurality of wavelength components, said prescribed fraction being less than a maximum number of wavelength components receivable by said node;  
 a network management element for communicating with a network management center in the transmission system.  
   
     
     
         41 . The transmission system of  claim 40  wherein said plurality of network nodes includes N network nodes, where N is an integer greater than or equal to 2, said prescribed fraction of the plurality of wavelength components that can be regenerated being at least equal to 1/Q, where Q is an integer denoting a number of nodes that can be successfully traversed by any of the plurality of wavelength components without regeneration.  
     
     
         42 . The transmission system of  claim 40  wherein said regenerator arrangement comprises at least one user interface coupled to a local port of the optical switch for conveying traffic between the transmission system and a source of traffic external to the transmission system.  
     
     
         43 . The transmission system of  claim 40  wherein said prescribed fraction of the plurality of wavelength components is a fixed percentage of said maximum number of wavelength components receivable by said node.  
     
     
         44 . The transmission system of  claim 40  wherein said prescribed fraction of the plurality of wavelength components is a variable percentage of said maximum number of wavelength components receivable by said node.  
     
     
         45 . The transmission system of  claim 40  wherein said regenerator arrangement is configured to perform 3R regeneration.  
     
     
         46 . The transmission system of  claim 40  wherein said regenerator arrangement is configured to perform 2R regeneration.  
     
     
         47 . The transmission system of  claim 40  wherein said regenerator arrangement is configured to perform 1R regeneration.  
     
     
         48 . The transmission system of  claim 40  wherein said regenerator arrangement is configured to perform regeneration and wavelength conversion.  
     
     
         49 . The transmission system of  claim 40  wherein said regenerator arrangement is configured to perform regeneration without wavelength conversion.  
     
     
         50 . The transmission system of  claim 40  wherein said regenerator arrangement is configured to perform amplification dispersion compensation.  
     
     
         51 . The transmission system of  claim 40  wherein said regenerator arrangement is configured to perform PMD compensation.  
     
     
         52 . The transmission system of  claim 40  wherein said optical switch is an optical add/drop multiplexer.  
     
     
         53 . The transmission system of  claim 40  wherein said optical switch is an optical cross-connect.  
     
     
         54 . The transmission system of  claim 40  wherein said optical switch is a reconfigurable optical switch.  
     
     
         55 . The transmission system of  claim 54  wherein said reconfigurable optical switch is an all-optical reconfigurable optical switch.  
     
     
         56 . The transmission system of  claim 42  wherein said user interface includes at least one transmitter/receiver interface for communicating with the external source of traffic and for performing regeneration when otherwise in an idle mode of operation.  
     
     
         57 . The transmission system of  claim 56  wherein said transmitter/receiver interface is a short-reach transmitter/receiver interface.  
     
     
         58 . The transmission system of  claim 42  wherein said at least one user interface comprises a plurality of user interfaces.  
     
     
         59 . The transmission system of  claim 58  wherein said plurality of user interfaces each includes at least one transmitter/receiver interface for communicating with the external source of traffic and for performing regeneration when otherwise in an idle mode of operation.  
     
     
         60 . The transmission system of  claim 59  wherein said optical switch is a reconfigurable optical switch.  
     
     
         61 . The transmission system of  claim 40  wherein said regenerator arrangement comprises at least one dedicated regenerator coupled to a local port of the optical switch.