adjustment. These oscillations grew from a sm all initial tilt error. In Figure
8.28(b), the simultaneous control stepping was stopped and instead e ach WSS
was adjusted through three control iterations before moving sequentially to the
next ROADM. The resulting tilt error is shown after all three ROADMs have
been adjusted. After just two adjustments around the loop, the tilt error is
negligible.
The use of node-sequenced channel power tuning avoids instabil ities due to
competing channel power adjustments. Sequencing through all nodes in a net-
work, however , does not scale well. The time required to adjust the network can
become large. The dynamic domains technique uses the channel paths in the
network to define domains between which strong channel ...