title: Effect of link margin and frequency granularity on the performance of a flexgrid optical network.
abstract: We show how dynamically adjustable modulation formats can be used to reduce link margins in flexgrid networks, reverting to lower order QAM due to reduced OSNR, if ageing occurs. Spectral savings amount to as much as 63% gain in capacity across a network using 64QAM with a fine frequency granularity of 6.25 GHz, with variable baud rate transponder. Further, a fixed baud rate, demand multiplexed transponder with adaptive modulation has been suggested. These transponders provide twice as much network capacity as compared to widely used fixed baud rate transponders operating at fixed grid of 50 GHz.
authors: Abhijit
authors: A
authors: Mitra
authors: Andrew
authors: A
authors: Lord
authors: Subrat
authors: S
authors: Kar
authors: Paul
authors: P
authors: Wright
mesh_terms: D000465:Algorithms; D003195:Computer Communication Networks / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D055096:Optical Devices; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*