Optical add/drop wavelength division multiplex systems
AssigneeAlcatel
InventorsKevan Peter Jones, David James Wall
Life of this patent
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Abstract
An optical-wavelength division multiplexing system, method and branching unit. The arrangement drops one, or more than one, predetermined wavelength signal(λ2) from a trunk(18) onto a branch and adds signals(λ2′) at the predetermined wavelength, or at a predetermined different wavelength from the branch out of the trunk. A sensor(34) senses the level of the signal(s) dropped and a controller(36), which responds to the control signal, adjusts the level of the add signal(s)(λ2′) to an optimum level for adding to the trunk(18).
Claims18
An optical wavelength division multiplexing add/drop branching unit for dropping at least one predetermined carrier wavelength, for carrying traffic signals, from a trunk to a branch terminal via a drop branch and for adding at least one carrier wavelength, for carrying traffic signals, from the branch terminal to the trunk via an add branch, the branching unit comprising:
- A) drop signal sensing means for sensing the level of the at least one predetermined carrier wavelength dropped on the drop branch and for providing a control signal related to the level of said at least one dropped carrier wavelength;
- and
- B) control means responsive to the control signal for adjusting the level of the at least one carrier wavelength added on the add branch to an optimum level for adding to the trunk.
An optical fiber wavelength division multiplex communication system comprising:
- A) a trunk cable extending between two remote transit/receive stations;
- B) an optical wavelength division multiplexing add/drop branching unit for dropping one or more predetermined carrier wavelengths from the trunk cable to a branch terminal and for adding one or more predetermined carrier wavelengths from the branch terminal to the trunk cable, each of the dropped and added predetermined carrier wavelengths having a level;
- and
- C) means associated with the branch terminal for sensing the level of the one or more predetermined carrier wavelengths dropped from the trunk and for adjusting the level of the one or more predetermined carrier wavelengths added to the trunk cable in response to the level of the one or more predetermined carrier wavelengths dropped from the trunk.
A method of operating an optical fiber wavelength division multiplex communication system in which multiple carrier wavelengths are transmitted and received along a trunk cable by remote transmit/receive stations each including a branching unit, the method comprising:
- A) transmitting multiple carrier wavelengths along the trunk cable;
- B) dropping one or more predetermined dropped carrier wavelengths from the trunk to a branch transmit/receive station;
- C) sensing the level of the dropped carrier wavelengths;
- D) adding one or more predetermined added carrier wavelengths from the transmit/rescue station to the trunk cable;
- and
- E) controlling the level of the one or more predetermined added carrier wavelengths as a function of the sensed level of the one or more dropped predetermined carrier wavelengths.
Dependencies are inferred from the claim text.