DWDM is usually used for long-haul transmission where wavelengths are packed tightly together over the C-band, up to 48 DWDM channels in 100GHz grid(0.8nm) and 96 DWDM channels in 50GHz grid(0.4nm). It's protocol transparent and suit applications including 10/1G Ethernet, SDH/SONET, 16/8/4/2/1G Fiber Channel, FTTx and CATV.
WDM can effectively save up the resource of fiber and cost of network. It helps to solve the shortage of optical fiber and transparent transmission of 5G business. With low-cost, low power consumption and small compact, it is widely used in metro aggregation and access layer to do transmission on a short time.