Views: 0 Author: Site Editor Publish Time: 2022-10-20 Origin: Site
CWDM has 18 wavelengths to choose from, but the supply chain of the middle 6 waves is relatively blank due to the water peak effect in the early fiber. The first six waves (1270nm-1370nm) of the 25Gbit/s CWDM scheme can be used in the low-cost configuration of the uncooled DML laser and PIN detector, and the mature industrial chain support has great advantages, which can well meet the 6-wave base station requirements.
The 25G SFP28 CWDM optical module has six CWDM channels. The available wavelengths are 1270nm, 1290nm, 1310nm, 1330nm, 1350nm, and 1370nm. It can support a transmission distance of up to 10KM.
In order to better understand 25G SFP28 CWDM, this article discusses the comparison of 25G SFP28 CWDM and other XWDM schemes.
1. Compare with 25G SFP28 DWDM
The 25G DWDM is capable of providing 45 channels that meet the requirements of the DWDM ITU 100Ghz Grid (a 25G DWDM SFP28 laser with a range of 40 km is currently under development). We know that in addition to optical amplifiers, non-coherent DWDM systems below 100G usually require a dispersion compensation module to compensate the line dispersion cost.
Therefore, the cost of the 25G DWDM SFP28 solution is much higher than that of the 25G SFP28 CWDM. This is why we recommend the 25G SFP28 CWDM scheme when 12 or fewer 25G channels need to be interconnected between sites and the distance is less than 40 km.
2. Compare with 25G SFP28 LAN WDM
The 25G LWDM SFP28 ranges from 1269.23nm to 1318.35nm and has 12 channels. This is the same number of channels available in 25G SFP28 CWDM. The optical components of the 25G SFP28 LWDM are relatively new and somewhat more expensive than those of the 25G SFP28 CWDM. However, the main advantages of the 25G SFP28 LWDM are support for a 40 km range and industrial temperatures (from -40°C to + 85°C). 25G SFP28 LWDM 40 km lasers are becoming more widely available in the market due to the competition between 25G SFP28 CWDM and 25G SFP28 LWDM which will make both types of transceivers cheaper.
3. Compared with 25G SFP28 MWDM
MWDM is a medium wavelength division multiplexing scheme. Based on the mature product of the first six waves of CWDM scheme, the 25 Gbit/s MWDM scheme expands the original six waves into 12 waves by shifting the wavelength of these six waves to the left or right respectively.
MWDM/LWDM both adopt 12 wavelength configuration, and DWDM wavelength tunable scheme can not be replaced by other schemes because of its port independent, wavelength adaptive characteristics, so if the low-cost tunable laser technology is mature in the future, DWDM scheme will be a more suitable choice. Although different XWDM technologies have their own advantages and disadvantages, the main current technical direction is to adopt a 6-wavelength CWDM configuration.
