What is dwdm & otn ??

Question

Accepted Answer

DWDM stands for Dense Wavelength Division Multiplexing and OTN stands for Optical Transport Network.

DWDM is a technology that allows multiple data signals to be transmitted simultaneously over a single optical fiber.
It uses different wavelengths of light to carry multiple signals, increasing the capacity of the fiber.
OTN is a network protocol that enables the efficient transport of data over optical networks.
It provides features like error correction, performance monitoring, and multiplexing of different client signals.
DWDM and OTN are commonly used in long-haul and metro optical networks to achieve high-speed and high-capacity data transmission.

Accepted Answer

DWDM is successor of SDH. SDH can send maximum 40 Gbps per fiber pair theoretically but in practical case only 10g(STM64) is possible. But in case of DWDM 100G to 400G is possible on single fiber pair. How?

Analogy behind DWDM is simple. If we look on single flow of SDH, SDH sends a single signal over fiber pair that contains a gray light signal on fiber and this gray light contains a wide range of wavelength. In DWDM or we say in WDM this gray signal can be break into multiple coloured signal and every different coloured signal can be assigned to a single signal. Excited thing behind this analogy is that, these different coloured signals can be multiplexed together and can be sent over single fiber cable. Let's say every different coloured signal contains 10G rate so if SDH gray signal breaked into 10 different coloured signals then 10 signals of 10G rate can be sent over single fiber cable... So total rate would be 100G. Kudos 👌 we were sending only 10G over single fiber pair now using DWDM we are send 100 G which is 10 times of SDH.

OTN- OTN is successor of DWDM.

First - In WDM there was no frame structure and when there is no frame structure , maintenance will be very complicated as frames contain alarm and performance related data those are responsible for alarm reporting in case of faults.

Second - in OTN when data comes at interface of OTN system it wraps this data into containers and multiple containers data can be wrapped into a higher rate wrapper for example 10 10G signals can be wrapped into 100G wrapper and this single wrapped signal can be sent as a single signal. In WDM, WDM collects signal at interface and assigns single wavelength to this. If 40 channel DWDM system is there and every port has 2.5 G ingress stream then 40*2.5 = 100G possible. But this could be 40*10G =400G. Now in OTN if we have same scenario then we can combine these signals into higher rate by just transforming lower rate signals into higher ones and line side going to fiber can be used for future.

What is dwdm & otn ??

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What is dwdm &amp; otn ??

Top Prompt Personnel NOC Support- Transmission Engineer interview questions & answers

Popular interview questions of NOC Support- Transmission Engineer

What is dwdm & otn ??