View source for Frequency grid

For telecommunications, a '''frequency grid''' is a table of all the central [[Physics:Frequency|frequencies]] (and corresponding [[Wavelength|wavelength]]s) of channels allowed in a [[Social:Communications system|communications system]].
The most common frequency grid used for [[Physics:Fiber-optic communication|fiber-optic communication]] is that used for channel spacing in [[Wavelength-division multiplexing|Dense Wavelength Division Multiplexing (DWDM)]] at wavelengths around 1550&nbsp;[[Nanometre|nm]] and defined by ITU-T G.694.1.<ref>ITU-T G.694.1, "Spectral grids for WDM applications: DWDM frequency grid" [http://www.itu.int/rec/T-REC-G.694.1/en ITU-T website]</ref> The grid is defined relative to 193.1&nbsp;[[Physics:Terahertz radiation|THz]] and extends from 191.7&nbsp;THz to 196.1&nbsp;THz with 100&nbsp;GHz spacing. While defined in frequency, the grid is often expressed in terms of wavelength, in which case it covers the wavelength range of 1528.77&nbsp;nm to 1563.86&nbsp;nm with approximately a 0.8&nbsp;nm channel spacing.

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

==References==
<references />

==External links==
*[http://www.telecomengineering.com/downloads/DWDM%20ITU%20Table%20-%20100%20GHz.pdf Complete ITU grid table for 100&nbsp;Ghz spacing]
*[https://web.archive.org/web/20070927225305/http://www.ntt.co.jp/tr/0306/files/ntr200306085.pdf International Standardization Activities on Optical Interfaces]

[[Category:Multiplexing]]

{{Sourceattribution|Frequency grid}}