Patent ID: 7054562
Filing Date: 2006-05-30
Classification: H04B,H04J

Abstract:
1. A wavelength division multiplexed optical communication system having a transmission path carrying a WDM signal with a plurality of channel bands, comprising: an optical amplifier optically coupled to the transmission path of the system and having an associated amplified transmission window; a plurality of optical add-drop multiplexers each including a drop filter with an associated drop band capable of dropping at least one channel band from the WDM signal; said optical add-drop multiplexers injecting the channel bands into said fiber optic network such that the injected channel bands occupy a first edge portion of the amplified transmission window; a tunable edge filter optically coupled to the transmission path, said tunable edge filter having a pass band and a stop band; a network manager operatively connected to said tunable edge filter, said network manager adjusting said tunable edge filter such that the stop band of the tunable edge filter substantially blocks ASE wavelengths of unoccupied channel bands; said network manager assigning a first group of channels to a first channel band occupying the first edge portion of the amplified transmission window; said network manager assigning a second group of channels to a second channel band substantially adjacent to the first channel band in a channel adding direction, wherein the channel adding direction is away from the first edge portion of the amplified transmission window; said network manager adjusting a tunable edge filter in the transmission path such that a stop band of the tunable edge filter substantially blocks ASE wavelengths of unassigned channel bands; said network manager assigning an N-th group of channels to an Nth channel band substantially adjacent to the (N−1)th channel band in a channel adding direction; said network manager adjusting the tunable edge filter in the transmission path such that the stop band of the tunable edge filter substantially blocks ASE wavelengths of unassigned channel bands; said network manager decommissioning the Nth channel band, the Nth channel band being substantially adjacent to an (N−1)th channel band in a channel deleting direction, wherein the channel deleting direction is towards the first edge portion of the amplified transmission window; and said network manager adjusting the tunable edge filter in the transmission path to expand a stop band of the tunable edge filter to substantially block ASE wavelengths of the decommissioned Nth channel band.