Source: People's Post and Telegraph
Recently, a scientific and technological news reported by some media has attracted wide attention.China's first private Wi-Fi satellite will provide free satellite networks worldwideThe goal isProviding free satellite networks worldwide in 2026。 Users will be able to search the satellite network and access the Internet with one key. Compared with the existing operators, it is more helpful for the area not covered by the current ground network.
Wi-Fi satellite is the first gimmick thrown by Americans. Four years ago, there was a plan called Outernet in the United States to launch hundreds of low-orbit satellites to provide Internet information services for the 430 million people in the world who can not access the Internet.
According to Richard, chief operating officer of Outernet,Users only need a small box to connect to the satellite, and become a Wi-Fi hotspot, so that users can timely understand the global dynamics and support transnational distance education.
The working principle of this project isLike radio and television satellites, only downlink signals do not have uplink access, and can only receive specific information. They do not support all social applications such as WeChat, Alipay, QQ and so on.
The essence of the Internet isinteractiveThe 802.11 protocol based on Wi-Fi defines the rules of two-way interaction, and the communication mode that can not interact information can not be called Wi-Fi. The project stalled because it did not raise funds.
In the past two years, the media have reported that Google and SpaceX are cooperating to launch 700 communication satellites to build a global wireless Internet.
Unlike Outernet, it can theoretically achieve bidirectional communication, but it must have its own VSAT satellite antenna. Because it involves frequency control, not only in China,No country is allowed to erect it privately.Moreover, the satellite antenna is complex and inconvenient to carry.It is not suitable for ordinary users at all.
Zuckerberg also followed suit in the global Wi-Fi project, using a UAV with a wingspan of more than 30 meters, and bought a British UAV company for that purpose.
The signal coverage radius provided by UAV to the ground is about 100 km, and its speed is about 100 km/h. The signal area with a radius of 100 kilometers is moving at high speed. You have to drive at a speed of 100 kilometers per hour to follow the signal area to get online. The plan has not yet been implemented.
SpaceX is the hottest Internet broadcaster.The plan, because it announced detailed technical solutions, insteadIt exposes the truth that its principle does not hold water.
According to its official documents, the typical coverage area of a satellite is 3.53 million square kilometers, which is only 6 countries in the world, equivalent to more than 9 Germany and 220 Beijing areas. Even considering the phased array technology adopted by the satellite, the real service area is smaller than the coverage area, but its scope is also astonishing. Human.
There will be tens of millions of users under such huge coverage. How much bandwidth can a satellite provide? Shared by so many people, how much can each person share?
Now, 20,000 iron towers have been built in Beijing alone, with more than one station on each tower. So, can such a satellite provide services to hundreds of Beijing areas, and the speed can be guaranteed? It's like beating an egg in the swimming pool. Can you still taste the egg soup?
There are now more than 5 million 4G base stations in the world, which are still far from being able to meet the needs of people's high-speed Internet access, and hundreds of thousands of satellites can effectively supplement these needs. I'm afraid we should add a number to the unit of quantity.
The global Wi-Fi program of satellites, hot balloons and UAVs has a common feature.That is to say, they all have large propaganda coverage. The coverage area of these methods is much larger than that of base stations, but the users under large coverage will be more, and the resources that individual users can share will be less, so that they can not access the Internet at all.
5G is about to be pre-commercialized. Small coverage of micro-base stations is a core feature. Reducing the coverage area, each base station serves fewer users, so that users can get a higher rate.The technological route of satellite Wi-Fi is fundamentally wrong.
Satellites usually useKu and Ka bandThis is determined by the physical properties of electromagnetic waves, Musk'sIt is impossible to communicate directly with satellites. The microwave and radio frequency components that can communicate with satellites must be installed before direct connection is possible.
Wi-Fi satellites must operate in low orbit, and the lower the orbital resources are, the more tense they are. Now there are more than 1800 satellites in orbit all over the world. There are many satellites in high, middle and low orbits. In a few years, thousands of satellites have been stuffed into low orbit. Is that possible?
In 2015, Musk announced a five-year plan to launch 4,425 satellites by 2020. Now half the time has passed, and finally two satellites have been launched. There's more than a year left.4423 satellitesDo you think it's too late to launch?
Seeing that it is about to reveal its stuffing, the plan has now turned into 12,000 pieces, which will be launched before 2025, and this news has been heated by some domestic media. It may be a simple calculation. Now there are 2320 days to 2025. There are 11 998 satellites to be launched, with an average of 5.4 satellites to be launched every day, and the holidays are endless. Do you believe it?
Why are there so many untenable technological solutions? It's a distraction to attract venture capitalists, make PPT beautiful, and design an exciting statement that can fool you into investing. And? And then there's no more. The scientific community in the United States calls such schemes
The United States has begun to be vigilant and excluded from paper project. This evil wind has blown into China, reminding relevant departments and investors to be highly vigilant against the Wi-Fi satellite program and not to be a big grievance.
Editor: Liu Peiyu