Passive Optical Network
一、WDM Optical Network
WDM Optical Network is a technology multiplexing a number of optical carrier signals into a single optical fiber by using different wavelengths of laser light. This technique enables bidirectional communications over one strand of fiber, as well as multiplication of capacity. Infiberone supplies a complete series of WDM Optical Network Solutions, such as multiplexers, splitters, amplifiers, attenuators and other passive optical components.
1. CWDM TOPOLOGY：
2. Characteristics of CWDM:
ITU-T G.694.2 CWDM Grid:
Nominal Central Wavelengths: 1271nm, 1291nm,……1611nm, 18 wavelengths in total.
3. Network element Parameters:
二、 DWDM Network:
2. Optical Bands
3、 Channel Spacing:
Crosstalk occurs in devices that filter and separate wavelengths. A proportion of optical power intended for a specific channel is found in an adjacent or different channel.
Effect: Generation of additional noise affecting optical signal to noise ratios (OSNR), leading to bit errors.
Solutions: use appropriate optical channel spacing, for example 0.4nm……10Gbps.
5、 FWX/Four wave mixing:
This interference phenomenon produces unwanted signals from three frequencies (fxyz=fx+fy-fz) known as ghost channels. As three channels automatically induce a fourth, the terms four wave mixing is used. FWM is problematic in systems using dispersion-shifted fibers (DSF). Wavelengths travelling at the same speed at a constant phase over long periods increase the effect of FWM.
Effects: Power transfer to new signal frequencies (harmonics), channel crosstalk, and bit errors.
Solutions: use of fibers or modules with reverse CD values (DCF/DCM)
6. Polarization Mode Dispersion (PMD)
PMD refers to the effect when different polarization modes (fast axis and slow axis)of a signal statistically travel at different velocities due to fiber imperfections. The time difference is called Differential Group Delay (DGD).
Effects : decrease of peak power, distortion of pulse shape, and bit errors.
Solutions: Lay fiber carefully ( No stress), use new fiber with low PDM values, exact fiber geometry.
三、 FTTX Solutions:
Infiberone can provide various kinds of PLC splitters to be used for PON/FTTx solutions, like LGX/MINI/BOX/BARE FIBER/1RU RACK/WALL-MOUNTED/TRAY TYPE etc.
四．Optical Protection System:
1. 1:1 Optical Line protection:
2. 1+1 OLP:
3. Optical Bypass Protection:
MTP Cabling Products
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