ITU Frequency Bands and Grids in WDM Fiber Optic Communication Systems
To provide a very high capacity for optical transmission systems, it is desirable to allow as wide a range as possible for the system operating wavelengths.
The International Telecommunications Union (ITU) has divided the telecom wavelengths into a ITU frequency grid; the grid is divided into bands.
Channel Spacing in DWDM, CWDM and WWDM Fiber Optic Systems
The channel spacing is defined to be the nominal difference in frequency or wavelength between two adjacent optical channels.
The ultimate capacity of a WDM fiber system depends on how closely optical channels can be packed in the wavelength domain.
“Grids” are used for location of nominal central frequencies in WDM systems. ITU defines a set of frequency grids for WDM applications.
In a given spectrum band, the number of channels in DWDM and CWDM Systems depend upon the particular channel spacing of the grid.
Unidirectional and Bidirectional WDM Systems
Unidirectional, as the name implies, only allowing transmission in one direction, while bidirectional allow transmission in two opposite directions.
This artitle provides the linear and ring link configurations for single-channel interfaces of DWDM multichannel optical systems in physical point-to-point and ring applications.
Lfiber offers flexible linear and ring link configurations in WDM systems. Ring with or without optical add drop multiplexing (OADM) is available.
Click the following link to learn more and Discover the Fiber-optic World.