Patent ID: 6449072
Filing Date: 2002-09-10
Classification: G02B,H04J,H04Q

Abstract:
An add/drop multiplexer for use in a wavelength division multiplexed optical network, the add/drop multiplexer having a first trunk input for receiving traffic signals from a first part of a first trunk fiber, a second trunk input for receiving traffic signals from a first part of a second trunk fiber, a first trunk output for outputting traffic signals to a second part of the first trunk fiber, a second trunk output for outputting traffic signals to a second part of the second trunk fiber, a branch input for receiving traffic signals from a branch input fiber, and a branch output for outputting traffic signals to a branch output fiber;the add/drop multiplexer comprising: means of routing from the first trunk input to the branch output a first set of traffic signals at carrier wavelengths predetermined for transmission of signals from the first trunk fiber to a branch station and for routing from the second trunk input to the branch output a second set of traffic signals at carrier wavelengths predetermined for transmission of signals from the second trunk fiber to the branch station, and means for combining said first and second sets of traffic signals for output at the branch output; means for separating traffic signals received at the branch input into a third set of traffic signals at carrier wavelengths predetermined for transmission of signals from the branch station to the first trunk fiber and a fourth set of traffic signals at carrier wavelengths predetermined for transmission of signals from the branch station to the second trunk fiber, and means for routing the third set of traffic signals to the first trunk output and the fourth set of traffic signals to the second trunk output respectively; and one or more amplifiers located on traffic signal paths determined by said routing means, such that said one or more amplifiers amplify each routing for traffic signals determined by said routing means and each of said one or more amplifiers is adapted to amplify traffic signals for a plurality of said routings.