CWDM or coarse wavelength Division Multiplexing means that the two or more signals are multiplexed onto a single fiber, where one of the signals is in 1550nm band and the other one is in 1310nm band. CWDM Grid Transceivers are designed to tap the wavelengths between 1270nm and 1610nm with a channel spacing of 20nm. The data reach of CWDM Grid Transceivers is 60km for a 2.4Gbps signal and these are quite useful in metropolitan applications. Cozlink manufactures CWDM Grid Transceivers that are used in cable television networks, where different wavelengths are used for the downstream and upstream signals. CWDM Grid Transceivers from Cozlink are compatible with CISCO, Juniper, and others.