DETERMINATION OF CHANNEL OSNR AND CHANNEL OSNR MARGIN AT REAL NETWORK CONDITIONS

摘要

A method of determining contributions of different sources of signal degradation for optical signals transmitted over an optical link in an optical transmission system, comprising measuring a performance value (P) of a signal transmission on said optical link, deriving, from the performance value, an auxiliary noise power value (P_N) based on a predetermined relationship between the performance value (P) and the auxiliary noise power value (P_N), wherein the auxiliary noise power value (P_N) comprises contributions of amplified spontaneous emission power (P_A) generated on the optical link and a link-related equivalent noise power contributions (P_L) representing other sources of signal degradation upon transmission on the optical link, measuring or deriving an OSNR-related value (Q) for the signal transmission on the optical link, wherein the OSNR-related value (Q) corresponds to or is at least indicative of an actual OSNR on the optical link, and distinguishing, based on the auxiliary noise power value (P_N) and on the OSNR-related value (Q) between noise power contributions of amplified spontaneous emission and link-related equivalent noise power contributions.