For telecommunications, a frequency grid is a table of all the central frequencies (and corresponding wavelengths) of channels allowed in a communications system.

The most common frequency grid used for fiber-optic communication is that used for channel spacing in Dense Wavelength Division Multiplexing (DWDM) at wavelengths around 1550nm and defined by ITU-T G.694.1. The grid is defined relative to 193.1THz and extends from 191.7THz to 196.1THz with 100GHz spacing. While defined in frequency, the grid is often expressed in terms of wavelength, in which case it covers the wavelength range of 1528.77nm to 1563.86nm with approximately a 0.8nm channel spacing.

For practical purposes, the grid has been extended to cover 186THz to 201THz and subdivided to provide 50GHz and 25GHz spaced grids.

References

External links

• Complete ITU grid table for 100

• International Standardization Activities on Optical Interfaces