This article discusses the function of WDM technology OADM based systems, the node structure and its products and applications, and its drop multiplexing tributary signals in wavelengths, called optical channel. OADM node device is one of the key equipment of all-optical network.

WDM signals in channel containing a plurality of wavelengths, these channels are multiplexed on a single optical fiber in transmission, each wavelength channels are independent of one bearer traffic.

Assume an optical fiber in only one wavelength of light transmitted signal, then with respect to the cost of fiber, this is expensive. If the transmission in one fiber in a variety of wavelengths of light signals and optical signals between each other and do not interfere with each other, so that both cost and improve the transmission bandwidth. WDM technology is currently in an optical fiber in the transmission of multiple wavelengths of light signals. Optical signal representative of each wavelength channel, multiple channels in a single optical fiber to transmit data in the same time, that is, to an optical fiber reuse.

OADM in the optical domain of traditional electrical SDH add-drop multiplexing time domain functions performed in, but also transparency, can handle any format and rate signals, which is more than in the SDH network used in the electric ADM (add-drop multiplex device) superior.

Drop explanation here is on the road and down the road.

What that means is the road into the OADM optical signal, wavelength add a new channel, and other channels multiplexed onto the fiber together.

Down the road, which means that entering the OADM optical signal, remove one wavelength channel, and other unrelated channel directly through the optical add-drop multiplexer. Note: By way of a channel directly to the device using the business process, not the truncated mean.