Patent ID: 7254339

Claim:
A power controlling network element for a wavelength division multiplex (WDM) communication system in which radiation propagating in the system is partitioned into a plurality of wavebands, each waveband being associated with an optical channel, the element being operative for controlling a power of one or more optical channels being transmitted through the element and for controlling a power of one or more optical channels being added at the element, the element comprising: a) measuring means for measuring the power of each optical channel output from the element, the power of a new optical channel being newly added at, or newly transmitted through, the element being initially at a level insufficient to disrupt existing optical channels; b) a channel control unit for selectively transmitting to an output of the element the one or more optical channels of input radiation received from the system, and for individually controlling the power of said one or more optical channels transmitted to the output; c) generating means for generating and controlling the power of the one or more optical channels being added at the element, and for emitting said one or more optical channels to the output; and d) controlling means for receiving data from the measuring means indicative of the power of each optical channel output from the element, and for controlling the power of each optical channel to within predetermined power limits by increasing the power in a stepwise incremental manner, thereby reducing power overshoot in said one or more optical channels, wherein the controlling means is operable for monitoring data corresponding to the radiation received at the measuring means, for determining whether or not unintended radiation is present at radiation wavelengths corresponding to optical channels which at least one of the channel control unit and the generating means has not been instructed to respectively transmit or generate, and for instructing the at least one channel control unit and the generating means not to transmit or emit radiation at radiation wavelengths corresponding to the unintended optical channel.