IEC 61280-2-11:2006 pdf free download Fibre optic communication subsystem test procedures – Part 2-11: Digital systems – Averaged Q-factor determination using amplitude histogram evaluation for optical signal quality monitoring
1Scope
This part of lEC 61280 defines the averaged Q-factor and provides a procedure to measure itby using amplitude histogram parameters such as the standard deviation and average level.
The averaged Q-factor and amplitude histogram parameters are useful for monitoring changesin optical signal quality in installed optical networks.The average Q-factor is correlated withthe traditional Q parameter of a given optical channel.
With the averaged Q-factor test method signal, quality degradations due to optical signal-to-noise ratio(OSNR) degradation and to waveform distortion can be monitored:
. OSNR degradation, due to the following causes:
accumulation of amplified spontaneous emission (ASE);
– transmission line loss;
– channel crosstalk;
. waveform distortion, due to the following causes (usually simultaneously present):
– chromatic dispersion;
– polarization mode dispersion(PMD);
– optical nonlinear effects.
NOTE1 In some cases the main cause of signal degradation (OSNR degradation or waveform distortion) can beidentified by suitable processing of the measured data
NOTE 2 This method is insensitive to the optical signal quality variations created by timing jitter.
2Normative references
The following referenced documents are indispensable for the application of this document.For dated references, only the edition cited applies.For undated references, the latest editionof the referenced document (including any amendments) applies.
IEC 61280-2-2:Fibre optic communication subsystem basic test procedures – Part 2-2:Testprocedures for digital systems – Optical eye pattern, waveform, and extinction ratio
ITU-T Recommendation G.959.1 : Optical transport network physical layer interfaces
3Terms and definitions
For the purposes of this document, the following term and definition apply.
3.1
averaged Q-factor
parameter measured asynchronously on live optical digital signals for the purpose ofmonitoring the quality of those signals
NOTE This parameter is correlated with the traditional Q-factor parameter.4Abbreviated terms
ASE
amplified spontaneous emission
BER
bit error ratio
EDFA
Er-doped fibre amplifier
IM-DD
intensity modulated direct detection
NRZ
non-return-to-zero
OBPF
optical bandpass filter
OSNR
optical signal-to-noise ratio
OTN
optical transport networks
PMD
polarization mode dispersion
RZ
return-to-zero
SNR
signal-to-noise ratio
WDM
wavelength division multiplexing
5 Apparatus
The primary components of the measurement system are an optical bandpass filter, areceiver, a clock oscillator, an electrical pulse generator, a sampling module and a signalprocessing circuit, as shown in Figure 2.
IEC 61280-2-11:2006 pdf free download
