Wavelength Division Multiplexing, combining signals at different wavelengths onto one fiber with passive filters and separating them at the far end. Coarse WDM spaces up to 18 channels 20 nm apart from 1270 to 1610 nm; dense WDM packs dozens of channels 100 or 50 GHz apart in the C-band, often amplified. It multiplies the capacity of existing fiber without building new cable.
We're out of fiber on that route, drop a CWDM mux on each end and we get eight more circuits on the same pair.
Also heard as
- wave division
Related terms
Lambda
A single wavelength channel on a fiber, named after the Greek letter used for wavelength.
Window
A wavelength region where fiber loss is low enough to run links, such as 850, 1310 or 1550 nm.
Dark fiber
Installed fiber with no transmission equipment attached, either spare or leased bare to a customer who lights it.
PON
Passive Optical Network: a point-to-multipoint fiber network where unpowered splitters share one fiber among many users.