Wavelength division multiplexing (WDM) combines different frequencies of light onto a single fibre to increase its capacity by a factor of two, four, eight or more depending on the technology used.

Using VAMs with WDM components, normally unidirectional fibres can be made bidirectional; offering a 50% saving of fibre needed in the access network.

• Wavelength Division Multiplexing
• Course wavelength Division Multiplexing