The Advantages of WDM

1. Super large transmission capacity
The wavelengths in the WDM system are independent of each other, and can transparently transmit different services, such as SDH, IP, ATM and other signals to achieve multiple signals mixed transmission. Multiple optical signals are transmitted by penetrating different wavelengths into one optical fiber, and each wavelength carries different signals. The optical transmission rate converted by the system can be 2.5Gb/s, 10Gb/s, etc., and the number of multiplexed optical channels can be 40, 80 or more, so the transmission capacity of the system can reach the level of 1600Gb/s.
2. Long transmission distance
With the advantages of quotient gain, wide bandwidth, and low noise, the erbium-doped fiber amplifier (EDFA)has been widely used in optical fiber communication. It can cover the entire 1550nm wavelength C-band or L-band. So with a wide bandwidth EDFA, the WDM system can be amplified to achieve long-distance transmission, such as 640km.
Raman fiber amplifier has lower noise than EDFA, and it can realize ultra long distance transmission such as more than 2000km.
3. Save fiber resources
The N wavelengths are multiplexed and transmitted in one optical fiber, which can save a large number of optical fibers and reduce line costs. For a single-wavelength system, one SDH system requires one pair of optical fibers while in WDM system, no matter how many SDH sub-systems, the entire WDM system only needs one pair of optical fibers. For a 32*2.5Gb/s system, a single wavelength system requires 64 optical fibers, while a WDM system requires only 2 optical fibers. It is also very convenient to expand the line without modifying the line when the power allows, saving investment.
4. Smooth upgrade and expansion
Only need increase the multiplexed optical wavelength channels and the corresponding equipment , the transmission capacity of the system can be increased to achieve system expansion. The expansion will not adversely affect the optical channels already in use. Therefore, the upgrade and expansion of the WDM system is smooth, and it is convenient and easy to implement, thereby maximizing the protection of the initial investment in construction.
It is convenient that each wavelength optical channel multiplexed in the WDM system is independent to each other, signals such as voice, data, and image can be separately transmitted without interfering with each other
5. There is no excessive requirement for the dispersion of optical fiber
For a WDM system, no matter how high the transmission rate or transmission capacity of the system is, its fiber dispersion requirements can be satisfied G652 fiber
6. Can make full use of mature TDM technology
WDM technology can make full use of mature TDM technology, several or even dozens of 10Gb/s optical transmission and transmission systems can be used as wavelength multiplexing channels for wavelength division multiplexing it is quite easy to make the transmission capacity of the system reach 400Gb/s or 800Gb/s level or higher.