Military Industry of Great Powers: Build the Strongest Flanker

Limited by the lack of suitable laser equipment. The way the Wuhan Post Office transmits communication signals is to use analog signals and use a special optical modulator to modulate the analog signals into fluctuations in light intensity.

The signal density of this solution is extremely low and can only transmit information equivalent to 500 telephones at the same time, but compared with the digital signal speed they can achieve, it is still much better.

When seeing how easily the 101 Optoelectronics Research Laboratory completed 8.7gbit/s information transmission, especially since the optical module was so small, everyone was both excited and filled with emotion.

Zhang Shitao said: "Director Zhao, Wu Post has a new type of optical fiber. The zero dispersion point is shifted around 1550. It can not only eliminate four-wave mixing, but also has smaller attenuation..."

Zhao Guoqing's eyes lit up. Hearing these parameters, it should be 655 optical fiber.

Zhao Guoqing said: "It's great. It can solve four-wave mixing. We can increase the utilization of fiber frequency bandwidth by another twenty times. Institute 101 can now build a wavelength division multiplexer with twenty bands!"

"..."

what does that mean?

Zhang Shitao must have noticed it.

Dean Zhang said: "The country has already started to demonstrate in the past two years to establish a digital computer interconnection network connecting major colleges and universities, and whether to use mature cables or optical fibers. I think that technically, optical fibers are already very mature. , and the advantages are huge!”

Zhao Guoqing said: "Not only the computer Internet, wired telephones, telegraphs, televisions, and even wireless telephones, all information transmission can be transmitted using the backbone network."

"..."

Zhang Shitao opened his mouth wide and was speechless. Director Xiao Zhao had a very big appetite. However, he thought about it carefully and nodded. It was indeed a good idea, but it also had many difficulties.

"Telephones and telegraphs belong to the postal and telecommunications departments, TVs belong to the propaganda departments of various places, wireless phones have just started, and the Internet doesn't know which company it belongs to, but there must be more than one, and there are at least thousands of units classified into them. This merger is not that simple!"

Zhao Guoqing smiled and said: "We make suggestions. As for what to do, it is the leader's business. Actually, my idea is not to merge all the units. We just use a unified network transmission for backbone network and intercity network data transmission." The medium and each terminal are their own, which has a very big advantage. Once the backbone network is established, data services can be provided."

To put it bluntly, it means sharing part of the money for the phone and TV. Zhao Guoqing also understands that he has overthought it and this matter is beyond his control.

But it is obvious that this is very economical and can provide the basis for subsequent mobile phone signal coverage. As long as the base station connects the signal to the main network, full network communication can be achieved. This idea is both advanced and practical.

Dean Zhang said: "Can it be realized?"

It is a very real problem. A network does not just have optical modules and optical fibers. Software and hardware conditions are indispensable.

Software protocols for network interconnection, such as TCPIP network protocol, transmit TV data and Internet phone data H.323 protocol.

Hardware equipment such as routers, switches, and equipment network cards, data processing also requires servers, and what services the servers can provide also require a series of software and hardware environments...

Director Xiao Zhao said with certainty: "It can be achieved!"

It is not that you cannot develop network protocols yourself, but you must also consider the issue of integrating with international standards. The TCPIP protocol is free and open to the public and can be used directly.

As for routers, switches, and network cards, there are also foreign products, and there is no technical threshold for self-development, and the performance can be higher. Teacher Xiao Zhao seems to see only colorful tickets.

The idea of ​​building an information highway was also recognized by Minister Zhu of the Ministry of Science and Technology during his investigation in the afternoon, but he did not give any instructions on the spot.

This is a matter of national strategy, and the Ministry of Science and Technology cannot take the lead.

And Zhao Guoqing got a rare moment of respite.

The next day, the expert team from the Wuhan Postgraduate Institute was preparing to leave Lucheng.

Zhao Guoqing sent Ruan Yu, an engineer from the Optoelectronics Research Laboratory, with two twenty-complex wavelength division composite optical modules from the 101 Institute.

Dean Zhang Shitao said: "This time I have learned a lot. Director Zhao, thank you to the comrades of Institute 101 for the reception!"

Zhao Guoqing shook hands with Zhang Shitao tightly and said, "I also ask the comrades from the Wuhan Postgraduate Institute to send samples of the new optical fiber as soon as possible."

"Haha!" Dean Zhang Shitao laughed and said, "I have already called back. The people transporting the optical cables have already set off. Maybe they will arrive in Lucheng before I get to Wushi!"

"Thanks!"

After seeing off the Wuyou Institute group, Zhao Guoqing rarely had time to breathe. Teacher Xiao Zhao began to arrange the key tasks for the next stage of Institute 101.

He gathered the backbones of software and hardware design and information department of 101 Institute. A total of 27 key members, plus 48 college students who just graduated last year, formed a team of 75 people. In the history of 101 Institute, , is a team second only to the EDA project, and some people are also transferred from the EDA software project.

In the lecture hall of Institute 101, Director Xiao Zhao sent the TCPIP protocol specification text to everyone.

"The TCPIP protocol is divided into seven layers of software and hardware protocols. Of course, it can also be simplified into a four-layer protocol. They not only have regulations on the format of transmission on the network, but also have regulations on hardware standards and software regulations."

Zhao Guoqing drew a thick line on the blackboard, and the two sections of the thick line drew wide area networks. Each wide area network is connected by several local area networks.

He pointed to the thick line and said: "The Internet of Things is more like a road. The backbone network line is a national highway. A province is a large wide area network, which consists of several small municipal wide area networks, which are further subdivided into a local area network composed of a school... "

Zhao Guoqing explained in detail the role of routers in the network, the way information is forwarded, and the switch components of LAN and so on.

"For different types of applications, they will use different protocols in the application layer according to their own needs. Mail transmission applications use the SMTP protocol, World Wide Web applications use the HTTP protocol, and remote login service applications use the TELNET protocol. These protocols are related to I have arranged for people to collect the information."

"What you have to do now is to familiarize yourself with the specifications. The time given to you is very short. You only have one month to familiarize yourself with the protocol standards. You will be assessed after one month..."

Engineer Li Shunyi said: "Director Zhao, we have never been exposed to the TCPIP protocol. What should we do if there is a problem?"

Zhao Guoqing said: "I will be with you most of the time this month. If you have any questions, you can ask me, or you can go to the HKUST library to find information. Their library is more complete than our 101 library."

Zhao Guoqing had just arranged the development of network equipment. The next day, he received a specially sent optical cable from the Wuhan Postgraduate Institute.

Good guy, six volumes were brought here in a specially made truck. Sitting in the passenger seat was a young comrade from the Wuyou Academy.

"Hello, Director Zhao, there are six rolls of optical cables in total. Each roll has a standard length of 4,000 meters. They are all six-core optical cables. We also sent standard optical fiber connectors and optical fiber fusion connection equipment!"

"Thank you so much!"

Wuyouyuan is so thoughtful, even though 101 of these things are available.

These optical cables were sent to the Optoelectronics Research Laboratory as soon as possible, and Zhao Guoqing watched the tests in person.

"Connect the entire roll of optical fiber for testing and put it directly into the wavelength division multiplexer!"

Zhong Jigang nodded, and everyone unloaded the optical cable together. They carefully removed the optical cable one by one and separated out six optical fibers.

Fiber optics can be bent, but they cannot be folded. One piece is four kilometers long, so six strands are 24 kilometers. A total of six rolls are 144 kilometers.

After a while, the entire laboratory was filled with slender optical fibers, and connecting equipment was used to connect the optical fibers one by one to obtain a single-mode optical fiber 144 kilometers long.

Zhong Jigang carefully connected the two ends to the wavelength division composite optical module.

Turn on the testing equipment.

A burst of green light indicates that the device is normal.

"Director Zhao, all testing equipment is normal, we can start!"

Zhao Guoqing nodded, and Zhong Jigang pressed the button.

"1gbit/s..." the numbers lit up on the display.

"That's great, it's a record, it can be transmitted over 144 kilometers!"

"Optical signal attenuation noise 6db..."

"I didn't expect that there is still some margin. The noise is completely acceptable. I think it will be no problem if we add another 20 kilometers!"

As the numbers get bigger, it means the density of data being transmitted is also getting bigger.

"Single-band transmission can reach the limit of 8.7gbit/s of the optical module."

Zhao Guoqing nodded and said: "Start compound light wave transmission, increase slowly!"

1330 nm and 1550 nm light waves appear at the same time.

Two data appeared on the display at the same time, still starting from 1gbit/s.

"Director Zhao, composite light waves can be identified and decomposed, and signals can be transmitted..."

Teacher Xiao Zhao was finally relieved.

"This Wuyouyuan is really no small matter!"