The Challenge in Measuring OSNR
Optical signal-to-noise ratio (OSNR) has long been recognized as a key performance indicator in wavelength-division multiplexing (WDM) networks, because it provides a multichannel assessment of signal quality in a very short time.
OSNR also predicts bit error rate (BER) within just a few minutes, while typical BER tests must run for hours or days.
By measuring OSNR and channel spacing on a given fiber, optical spectrum analyzers indicate if it is possible to substantially increase the number of channels and hence total bandwidth. By allowing an increase in channel count or transmission speed via spectral width validation at each wavelength, EXFO’s OSAs help carriers maximize existing investments in their network.
The advent of higher data rates and new components have led to the introduction of three different OSNR methods depending on the network's characteristics:
- IEC 61280-2-9 for 10G and below, without ROADMs
- In-band OSNR, for 10G with ROADMs, or 40G noncoherent networks
- Pol-Mux OSNR for coherent 40G/100G
EXFO’s OSA offer:
- Commissioning Assistant, the first Pol-Mux OSA for 40G/100G coherent DWDM systems
- WDM-Aware i-in-band, the most accurate and adaptive in-band method on the market for intelligent setup and analysis on a per-channel basis
- WDM Investigator delivers detailed information about the signal and noise for each channel and efficient impairment identification (Pol-Mux signals, carved noise, crosstalk, nonlinear effects, carrier leakage and PMD pulse spreading)