The incident of “Beidou dropped” trucks aroused the attention of the outside world.

According to previous news reports, Jin Deqiang, a truck driver in Botou City, Cangzhou, Hebei, passed the over-limit checkpoint in Fengrun District, Tangshan City on April 5. The car was detained and a fine of 2,000 yuan was imposed. Or because he could not accept the fine, Jin Deqiang committed suicide by taking pesticides, but the rescue was ineffective and died.

What is going on with “Beidou dropped”? The reporter of News ( interviewed the relevant hardware experts of logistics supply chain enterprises and the director of the Technical Equipment Working Committee of Guangdong Logistics Industry Association to analyze the issue in depth from a technical point of view.

Working principle of vehicle-mounted terminal equipment

First look at the working principle of vehicle-mounted terminal equipment. Trucks are equipped with corresponding terminal equipment to receive and transmit signal.

Liu Danhua, director of hardware solutions for logistics supply chain company Yiliu Technology, told reporters that the two core functions of the terminal are positioning and communication.

Among them, positioning actually relies on GPS or Beidou satellite network. That is, the satellite transmits a broadcast signal, and the device receives the signal and converts it into positioning data.

The communication function mainly solves the problem of uploading data to related platforms. That is, after the device receives the satellite signal locally, it converts it into the latitude and longitude of the positioning, and there are other states, and then reports the data to the platform. At this time, communication networks are needed, such as 2G, 3G, and 4G. Both China Mobile Telecom and China Unicom will have corresponding network services.

Three cases of disconnection

First of all, it needs to be clear that from a technical point of view, “Beidou disconnection” is related to the Beidou system itself. Not big.

Beidou positioning system is actually a kind of broadcast signal. After receiving it, the ground terminal equipment analyzes it and turns it into positioning data. So this incident has nothing to do with the Beidou satellite in the sky.

So, what technical factors will cause the so-called “Beidou offline”?