In 5G fronthaul networks, 25G optical SFP modules are widely used, especially 25G WDM optical SFP modules. Because this kind of optical SFP modules can transmit multiple signals on a single fiber, it saves fiber resources, but it has a higher cost than other 25G modules. At present, 25G SFP28 LWDM optical SFP modules on the market can also achieve multiple signal transmission on a single fiber, but the cost is lower. Therefore, 25G SFP28 LWDM modules have a trend to become a more flexible and stable solution in 5G fronthaul networks.
The full name of LWDM is LAN WDM. The 25G SFP28 LWDM module has 12 wavelengths, all of which belong to the O-band. Eight of them are standard wavelengths that are divided into the O-band spectrum according to 800GHz, and the remaining four wavelengths are 25G multiplexed. The four wavelengths of the CWDM optical SFP modules are 1269.23nm, 1332.41nm, 1313.73nm and 1291.10nm. Like the 25G WDM module, the 25G SFP28 LWDM optical SFP modules can also use WDM technology to multiplex multiple wavelengths onto a pair of optical fibers, which can save a lot of optical fiber resources.
The connection method of 25G SFP28 LWDM optical SFP modules is the same as that of 25G CWDM/DWDM optical SFP modules. It needs to be used together with the matching Mux/Demux, that is, LWDM Mux/Demux. You only need to insert four 25G LWDM optical SFP modules into the 25G switches at both ends, and then use 4 single-mode fiber jumpers to connect the optical SFP modules to the LWDM Muxes/Demuxes, and a single-mode fiber jumper is used between the two LWDM Muxes/Demuxes. The lines are connected.
The 25G SFP28 LWDM optical SFP modules can support multi-channel signal transmission on a single optical fiber. It compensates for the large dispersion of 25G CWDM modules and the high cost of 25G DWDM optical SFP modules lasers, and saves 5G fronthaul transmission while ensuring stable transmission. This is why it is a stable and cost-effective solution in 5G fronthaul networks, and it still has a good prospect in the development of 5G fronthaul networks in the future.