After all, without it, there would be no broadband cable. If something goes wrong, everyone in the building will be disconnected, and it will be very troublesome to repair it. However, on May 27th in Wuhan, the appearance of a new technology broke the stereotype that the weak current room must be equipped. Known as "all-fiber network solution", it solves the problem of the last 100 meter of optical fiber communication.
Under the overwhelming wave of 5G, what does the technological breakthrough of optical fiber communication mean?
Old k still talks to you first, one of the most important communication methods at present: optical fiber communication!
1969, Chinese physicist Gao Kun confirmed that super-transparent glass can effectively transmit signals by measuring the inherent loss of molten Shi Ying at 4 dB/km. Since then, he has devoted himself to the research of optical fiber communication, and everything has paid off. 197 1 year, the world's first optical fiber was born!
Although only one kilometer long, ten years later, the first optical fiber communication system was put into use. At this moment, most viewers don't have an optical fiber at home, and they have heard of light cats. Optical fiber transmission can overwhelm communication, naturally because it has many advantages.
The first thing to bear the brunt is wide channels and fast network speed. Some viewers may remember two "tentacles" on TV. At that time, in order to watch an episode of TV, people had to touch the antenna several times from time to time. Rao is very careful. Once a naughty child bumps into it, he has to re-debug it by hand.
In fact, the TV antenna uses VHF band, and the carrier frequency is only 48.5MHz to 300Mhz, resulting in a bandwidth of only 250MHz, which can only transmit 27 TVs and dozens of broadcasts. In communication, the higher the carrier frequency, the wider the frequency band that can transmit signals. The optical fiber carrier frequency of visible light frequency transmission is more than one million times that of VHF band.
Although optical fiber can't absorb every ray of light like a sponge, there will still be some loss in the propagation process, but if you think about the comparison between network cable and antenna, you can also see how effortless it is to eliminate the narrowest optical fiber and the widest antenna.
Some viewers may wonder, when did the antenna appear? Aren't you going to brag?
Then, if we pull out the cable TV, that is, the coaxial cable, and take a walk, no matter what medium or signal transmission is used, we will suffer losses, just like a piece of meat will retain a few drops of oil no matter what plate it is placed on. Even the most advanced materials, metallic coaxial cable will lose 40dB per kilometer when transmitting 800MHz signals, that is, the attenuation is more than 10000 times.
In contrast, the loss data of optical fiber is almost negligible. According to the statistics of experimental data, the loss per kilometer of optical fiber is below 0.35dB when transmitting the light of 1.3 1μm, which is about one fortieth of the thickness of a hair.
If the transmitted light is slightly thicker, such as 1.55μm, then its loss per kilometer is smaller, which can reach below 0.2dB.
What the audience should pay attention to is that the number before the unit dB can be very delicate. 40dB is not 200 times of 0.2dB, because-10dB means attenuation 10 times, while -20dB is attenuation 100 times. Every time you add one to the ten digits, the multiple is followed by a zero.
Therefore, under the same conditions, the power loss of optical fiber is 100 million times less than that of coaxial cable, and naturally it can run further. In addition to these, there are two killers of optical fiber transmission loss:
In any cable TV channel, the amount of loss is the same, so it is not necessary to use an equalizer similar to cable trunk line to equalize it.
The loss will not change because of the outside temperature, and there is no need to worry about the signal interruption caused by the fluctuation of the main line level because the weather is too hot or too cold.
What keeps the optical fiber signal stable is its excellent anti-interference ability. When I was young, parents would nervously ask their children to turn off the computer and TV without hesitation. But now, because the basic component of optical fiber is timely, its embrace is only open to light, no matter how ever-changing the electromagnetic field, optical signals will not be taken into account.
Because of this, the signal transmitted by optical fiber is not easy to be eavesdropped and has high fidelity, which is the key point in some application scenarios.
Then, what is the problem of "last 100 meter" for such excellent optical fiber communication?
In fact, this is a term in the communication industry, which refers to the distance between the computer room switch of the communication service provider and the terminal equipment such as the user computer. Due to the nature of optical fiber, the traditional "100 meter" solution is weak current room. Optical fiber only goes to the floor, and multiple switches are arranged on each floor. When you meet a company that requires bandwidth, the network cable you take out will be messy.
A company in Wuhan called Yiwang Wanlian was the first in the world to solve the problem of optical fiber graphics. You know, even if the optical fibers are fully armed, the protective cover of the waterproof layer is all in battle. A cable composed of dozens of optical fibers is only one centimeter in diameter.
Easy Net Wanlian's unique microtubule and micro-cable construction technology can build a passive optical network, that is, from the terminal to the unit, without any electronic equipment using power supply. This technology also solves the worldwide problem that the optical fiber itself is easily broken and fragile, and it is stressed or bent when used indoors. For example, the signal is interrupted and attenuated because a pet holds a molar or a naughty child fiddles with it casually.
At the same time, the heavy weak current room was abandoned. What computer room, what access switch, and the 86-screen ONU product developed in a network of Wanlian, which allows users to use optical fiber like plug-in charging, have all become yesterday's yellow flowers in the face of patented technology.
Hubei Post and Telecommunications Planning and Design Institute is the first building to enjoy refreshing, with more than 700 designers. At one time, everyone was worried that half of their uploaded works would have to start again because of insufficient bandwidth. Under the table, on the ground, all the "black snakes" crawled out from the weak current room.
After all the optical fibers were taken over, the designers' network was as smooth as silk. The only thing "sad" is the weak current room, because it was emptied and transformed into a utility room.
As we know, the stability and reliability of a system is inversely proportional to the number of devices in the system, just as the more people in a tour group, the more likely it is to have differences, and this all-fiber network scheme itself does not need dozens of amplifiers like wired systems.
So its stability can be said to be the world's leading, and the life of the optical fiber itself is very long. According to relevant statistics, a normal optical fiber can work for up to 750,000 hours. Think about it. A set of network cables that have worked stably for 85 years is an artifact for a design institute that pays attention to inspiration and accumulation.
According to the calculation of the optical law, the information transmission bandwidth of normal optical fiber is constantly increasing, doubling every six months, and the price will be reduced by 1 times without expanding the demand. This breakthrough in optical fiber communication technology led by China is also the last stumbling block of large-scale cable TV system.
Comrade Wang Qing, chief engineer of Hubei Post and Telecommunications Planning and Design Institute, sincerely felt the significance of all-fiber network after the experience. He believes that this will be another great opportunity for China to lead the world.
After all, 2 1 century is the century of information. Take investment as an example. People who pay attention to the news always see a step or two more than those who know it later. The same is true of trade between countries. The cost of optical fiber network is two-thirds of that of traditional copper broadband.
Old K also mentioned before that optical fiber is made of time, which is one of the most widely distributed minerals on the earth's surface. Who hasn't seen sand yet, right?
Timely reserves are so abundant, so with the progress of technology in the future, the cost of making them into optical fibers will only be further reduced. Low-cost, long-life and high-speed optical fiber means that there is no need to replace the "network cable" for decades.
The money saved by a family who doesn't change the network cable may not be considerable, but once this technology is widely used, how many families in China have saved a lot of natural resources?
For example, the copper mine originally needed for cable construction will be a gratifying figure. Viewers with a good memory may remember that the confidentiality of optical fiber communication was mentioned in the first half. In fact, all-optical network will also solve the problem of insufficient indoor coverage of 5 G.
In the 14th Five-Year Plan, it is proposed to build a "digital China" in the future, to control the sustainable development of all walks of life with information, and to face global changes. Under such a macro picture, massive data exchange will become the norm.
The physical characteristics of copper cable broadband determine that it cannot be supported for a long time, and the necessity of all-fiber network is prominent. After solving the problem of the last 100 meter optical fiber, the various conveniences brought once again confirm what Comrade Deng Xiaoping said: Science and technology are the primary productive forces.
Communication has always been China's strong point, and optical fiber communication will once again break through the barriers and lead the world. What kind of surprise will it bring? Old k will wait and see with you!