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High density and High Integration OTN wavelength Division Transmission system

Today, wavelength division multiplexing technology is in full swing, and a variety of new technologies emerge in endlessly. But the goal is the same, that is to meet the network era of operators. A long time ago, only CWDM coarse wavelength division could be used, the number of channels was not enough, and the transmission distance was also very limited. according to the attenuation of lines and equipment, 10G non-relay transmission of 40km has become a bottleneck. This kind of technical background obviously can not meet the needs of operators.

Fortunately, with the continuous progress of technology, DWDM dense wavelength division came out, and this technology has a qualitative leap over the two short boards of CWDM channel number and transmission distance.

First of all, let's talk about the number of channels, wavelength interval 0.8nm, which can allow 48 wavelengths in the band of dense wavelength division. This number means that each wavelength can transmit 10g of capacity, 48 waves can transmit 480g, if the single-wave rate is doubled, then the total capacity will also be doubled.

Secondly, when it comes to the transmission distance, there are two reasons why CWDM rough waves are considered to be short-distance transmission. First: its wavelength range is 1270 to 1610, the band is too large, no equipment can amplify the optical power of the whole band at the same time, so that the transmission distance is not far. At this time, you may think, in this case, I can also de-wave at the relay station, using OEO for signal regeneration relay. Then continue the transmission to reach the desired distance. This is the second point I would like to share with you. Because the number of channels is relatively small, and the distance of single-span transmission is only dozens of kilometers, just imagine, if an operator needs to direct 160g of data resources to another place of 300 kilometers, six or seven relay stations are needed to regenerate and relay. The cost is huge, and the maximum capacity is only 160g, which is not cost-effective.

Now that the reason has been analyzed, let's take a look at the dense wavelength division of DWDM. Can it be transmitted over longer distances? It is well known that the wavelength range of DWDM dense wavelength division is 1525 to 1565, and the amplification range of EDFA erbium-doped fiber amplifier is also in this range, that is to say, only one EDFA is needed to amplify the wavelength of the whole band. if the full configuration is 480g, only one EDFA is needed, and its amplification power can reach 30dB. If the fiber attenuation is calculated according to 0.25dB/KM, an EDFA can relay the 80KM. Based on this calculation, the cost of long-distance relay is much lower than that of CWDM.

Combining the above, the DWDM dense wavelength division scheme will be chosen for long distance and large capacity.

Nowadays, the technology is becoming more and more perfect, and there are many system platforms, which is gradually upgraded from the initial 2U+1U platform to 6U platform, that is to say, it is a platform with OTN, which is the well-known OTN optical transmission platform based on wavelength division system. Shenzhen Optical Road Science and Technology OTN optical transmission platform is highly dense and highly concentrated, various types of business cards can be centrally mixed in a 6U rack. There is also a network management single card to manage the business card above the rack, and the real-time data of each business card can be seen.

Next, let's take a look at the highly intensive and highly concentrated application platform of Shenzhen Optical Road Technology OTN.

As shown in the figure, the OTN platform can be point-to-point transmission or ring network transmission. Capacity according to what kind of de-wave card is equipped on OTN equipment, the maximum can achieve 40-wave de-wave of veneer, the maximum capacity of service card can reach 8-channel single fiber 10G capacity, if it is long-distance transmission, EDFA fiber amplifier veneer can be configured. There are also OLP, FEC and 1x1 protection cards to meet different project requirements.

Source of document: Shenzhen Optical Road Science and Technology

Editor: Zhou Danyang

Hot line: 18617148030

QQ: 2853921097

Attachment: http://down.51cto.com/data/2367093

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