What is Optical Networking?
Optical networking is a means of communication that uses signals
encoded onto light to transmit information among various nodes of a
telecommunications network. They operate from the limited range of a local-area network (LAN) or over a wide-area network (WAN).
What is WDM ??
WDM means Wavelength Division Multiplexing, this technology is widely used in optical fiber communication. By using WDM technology we can multiplex many optical carrier signals on to single optical fiber cable. This is bi-directional link.
How multiple optical carrier signals can be transmitted over a single fiber?
In Optical communication, it uses optical fiber cable as medium to communicate between two nodes. The data transmission between them is in the form of light, this light is generated by a particular type of lasers which are capable to transmit a light signal for long distance. This laser generates signal with particular wavelength, physically different wavelengths will be having different colors. In WDM each request will be transmitted with different wavelength because of this multiple requests can be transmitted over a single optical fiber. Two different wavelength signal never get mixed if they have proper band gap.
Why we have to use WDM ?
In optical networks, the medium optical fiber has bandwidth in terms of Tera Bytes, with this bandwidth we no need to go for WDM or multiplexing all the data can be transmitted over a single carrier along with this loss, distortion and cost can be reduced. But practically we can not use this, even though optical fiber has capability to transmit the data in terms of Tera Bytes per second but none of the existing electronics devices can accept this data rate, data will be lost if you transmit higher rate than it support, existing devices support in terms of Mbps. This limitation is called as "Electronic Bottle Neck", because of this reason we can not transmit all data over single carrier. If we transmit each data over separate link then cost for communication will be huge, in order to reduce the cost, to utilize the bandwidth of fiber properly Wavelength Division Multiplexing is used.
Maximum how many signals can be transmitted over a single fiber using WDM?
That completely depends on the band what user selected to transmit. Every band has limited number of channels, here channels means the number of wavelengths can be transmitted without interference. Each band is divided in to channels with a proper band gap between them.
Maximum how many signals can be transmitted over a single fiber using WDM?
That completely depends on the band what user selected to transmit. Every band has limited number of channels, here channels means the number of wavelengths can be transmitted without interference. Each band is divided in to channels with a proper band gap between them.
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