Patent ID: 6871020

Claim:
An apparatus connected to a node in an M-channel wavelength division multiplexed optical communication network, where M is equal to the number of channels operable to be multiplexed on a single fiber, said node adding one of said M channels to said fiber and said apparatus monitoring a power spectrum of N number of channels multiplexed on said fiber and controlling power of said added channel, said apparatus comprising: a power spectrum measurement system connected to said node, said system including a power detection circuit for detecting the power of said N number of channels, and calculating power for each of said N channels and transmitting a signal operable to control the power of said added channel, and a processing circuit connected to said detection circuit, said processing circuit calculating the power of said added channel wherein the calculated power of said added channel is approximately equal to (1−2d)P k j +d(P k−1 j +P k+1 j ), where P k j is the power of a channel in a span j that has the same wavelength of said added channel, said span j including a span carrying said N channels to said node, P k−1 j and P k+1 j are the powers of channels in said span j that are adjacent P k j , and d is a diffusion parameter.