Li Baoqiang's proposal was based on the idea of ​​establishing satellite communications.

The satellite communication system is actually a kind of microwave communication. It uses satellites as relay stations to forward microwave signals and communicate between multiple ground stations. The main purpose of satellite communication is to achieve "seamless" coverage of the ground. Since satellites work on several ground stations, Hundreds, thousands, or even tens of thousands of kilometers of orbit, so the coverage is much larger than that of ordinary mobile communication systems.

However, satellite communications require ground equipment to have large transmit power, and were not widely used in previous generations.

At present, Li Baoqiang's 400-watt radio station can achieve global communication, but Li Baoqiang is never satisfied. In his previous life, he often used maritime satellite phones in overseas missions, which made Li Baoqiang nostalgic.

Li Baoqiang happened to have contacted General Tao Zijun of the Kyoto Military Region not long ago. Li Baoqiang learned that there was a satellite ground station equipment and three communication relay satellites in the underground command center of the Kyoto Military Region. This news made Li Baoqiang salivate.

Tao Zijun also wanted to restore the satellite communication system, but suffered from the lack of rocket launches. In fact, Tao Zijun also thought of launching nuclear missiles, but Tao Zijun didn't have many nuclear missiles. Tao Zijun regarded it as a treasure, so he couldn't bear it.

Hawking's call reminded Li Baoqiang of the nuclear missile on the Ohio nuclear submarine. It was an intercontinental missile with a range of 8,000 kilometers. It was possible to launch satellites outside the atmosphere by changing the procedures.

Li Baoqiang proposed the idea of ​​using nuclear missiles to launch relay satellites, which was forwarded to Shangguanyang. Shangguanyang talked with many experts in this field and felt that it was very feasible.

There are relay satellites, ground consoles, and delivery vehicles. The only difference is the terminal equipment. This is very simple. You can still find a few maritime satellite phones. Although the components were burned by the solar storm, It can still be produced by taking medicine according to the picture.

After communicating with Tao Zijun, Tao Zijun also approved this method. Since Li Baoqiang is willing to consume three nuclear missiles, Tao Zijun must be secretly enjoying it. How can he disagree?

Restoring the satellite communication system was a major event in the second year of the end of the world and attracted the attention of many people.

People can't help but hope that more past civilizations will continue to recover, return to the past, and enjoy modern civilization.

Although this road is difficult and far away, it has finally begun. A good start indicates that the future will be wonderful.

A satellite communications department was established in the Huaxia Autonomous Region, specializing in the production of terminal equipment and a series of issues related to compatibility with relay satellites and satellite consoles.

For this emerging sector, satellite communications are indeed very troublesome.

The satellite communication system consists of three parts: satellite terminal, ground terminal and user terminal.

The satellite acts as a relay station in the air, that is, it amplifies the electromagnetic waves sent by the ground station and then sends them back to another ground station. The satellite body includes two major subsystems: spaceborne equipment and satellite matrix.

The ground station is the interface between the satellite system and the ground public network. Ground users can also enter and exit the satellite system through the ground station to form a link. The ground station also includes the ground satellite control center, and its tracking, telemetry and command stations.

User terminals are various user terminals.

In the microwave frequency band, the working frequency band of the entire communication satellite is about 500mhz wide. In order to facilitate amplification and transmission and reduce modulation interference, several transponders are generally installed on the satellite, and each transponder is assigned a certain working frequency band.

Satellite communications mostly use frequency division multiple access technology. Different earth stations occupy different frequencies, that is, they use different carriers, which is more suitable for point-to-point large-capacity communications.

Time division multiple access technology has also been widely used in satellite communications. That is, multiple earth stations occupy the same frequency band but occupy different time slots. Compared with frequency division multiple access, time division multiple access technology does not produce intermodulation. It eliminates interference and does not require frequency up and down conversion to separate the signals from various earth stations. It is suitable for digital communications and can allocate transmission bandwidth on demand according to changes in business volume, greatly increasing the actual capacity.

Another multiple access technology is code division multiple access (cdma), which means that different earth stations occupy the same frequency and the same time, but use different random codes to encode information to distinguish different addresses.

cdma uses spread spectrum communication technology, which has the advantages of strong anti-interference ability, good confidential communication ability, and flexible scheduling of transmission resources. It is more suitable for systems with small capacity, wide distribution and certain confidentiality requirements.

In the end, researchers from the Kyoto Military Region and the China Autonomous Region decided to adopt a medium-orbit satellite communication system. This communication system was used in previous maritime satellite phones.

Satellites are 2,000 or 20,000km away from the ground. The transmission delay is larger than that of low-orbit satellites, but the coverage is also larger. A typical system is the International Maritime Satellite System.

The medium-orbit satellite communication system can be said to be a compromise between the geostationary satellite system and the low-orbit satellite system. The medium-orbit satellite system has the advantages of both solutions, and at the same time overcomes the shortcomings of the two solutions to a certain extent.

The link loss and propagation delay of medium-orbit satellites are relatively small, and simple small satellites can still be used.

If both mid-orbit and low-orbit satellite systems use interstellar links, when users communicate over long distances, the delay of mid-orbit system information passing through the satellite interstellar link subnet will be lower than that of low-orbit systems.

And because its orbit is much higher than that of the low-orbit satellite system, the range that each satellite can cover is much larger than that of the low-orbit system. When the orbit altitude is 10,000km, each satellite can cover 23.5% of the earth's surface, so as long as A few satellites can cover the entire world.

If there are more than a dozen satellites, it can provide double coverage to most areas of the world. In this way, diversity reception can be used to improve the reliability of the system, and the system investment will be lower than that of a low-orbit system.

Therefore, in a certain sense, the medium-orbit system may be a superior solution for establishing a global or regional satellite mobile communication system.

Of course, if it is necessary to provide broadband services to ground terminals, there will be certain difficulties in the medium-orbit system. However, the performance of low-orbit satellite systems as high-speed multimedia satellite communication systems is better than that of medium-orbit satellite systems.

Currently there are only three satellites, which can only satisfy communications within Asia.

Li Baoqiang suggested that the development of satellites and the production of terminal equipment can be done slowly, but the first priority is to send the satellites into the sky. Even if it fails, it is still a bold attempt.

Li Baoqiang's idea was agreed by many people, and three communication satellites in the underground warehouse of the Kyoto Military Region were transported to Zhoushan.

The USS Ohio nuclear submarine was docked at the Zhoushan Military Port. Three nuclear warheads were carefully taken out, and satellites were installed at the same time as the original nuclear warheads. This is a huge change for nuclear missiles.

Because the weight, shape, and size of satellites and nuclear warheads have undergone tremendous changes, this change has an unpredictable impact on the flight of nuclear missiles and may have a fatal impact.

However, many aspects of nuclear missiles that need to be improved and adapted have not been modified. At present, no one can modify them. Those who can modify them may still be alive, but this is a systematic project. Even if there are a few knowledgeable workers, Even if I come down, I can't finish it at all.

Now is the end of the world. No one can create another nuclear warhead or rocket. The end of the world is so cruel, but hope still exists.

It has only been two years since the end of the world, but on the land of China, using Chinese communication satellites, American nuclear missiles are about to launch three communication satellites.

This is the miracle of the end of the world, which brings people infinite reverie and hope.

Hawking couldn't help but pray that the launch would be successful, because he was going to lead the nuclear submarine deep into the ocean, launch these three missiles, and go straight out of the atmosphere to an altitude of two thousand kilometers.
Chapter completed!