ZXMP M600 (V1.0) Technical Manual
A-4
A.4 Channel Interval
It refers to the nominal frequency difference (wavelength interval) between two
adjacent multiplex channels.
Channel intervals can be either even or uneven. Uneven channel intervals can be
used to suppress the Four Wave Mixing (FWM) effect of G.653 fiber. At present,
however, even channel intervals are used in most cases.
ITU-T Recommendation G.692 specifies that the channel interval of DWDM
system should be an integer multiple of 100GHz (about 0.8nm). At present,
generally two channel interval standards are used, that is, 200GHz (about 1.6nm)
and 100GHz (0.8nm).
IUT-T Recommendation G.694.2 specifies that the channel interval of the
CWDM system should be 20nm.
A.5 Central Wavelength or Central Frequency
It indicates the central wavelength or frequency to which each multiplex channel
in the WDM system corresponds.
The frequency criterion is used in the DWDM system. The working frequency
range of the system is 196.1THz~192.1THz. When the channel interval is
0.1THz, the corresponding central frequencies are 196.1THz, 196.2THz and so
on. When the channel interval is 0.2THz, the corresponding central frequencies
are 196.1THz, 196.3THz and so on.
Wavelength criterion is used for the CWDM system. If G.652 A or G.652 B
fibers are used, the central wavelengths are respectively 1471nm, 1491nm,
1511nm, 1531nm, 1551nm, 1571nm, 1591nm and 1611nm. If full-wave fibers
are used, the wavelength range is 1271nm~1611nm and the interval is 20nm,
then the central wavelengths are respectively 1271nm, 1291nm and so on.
