After calculation and analysis, these big data can produce results in real time at a glance. After the health code came out, it was copied and adopted in many places, but a new problem emerged, that is, the health codes in various places were used independently, and the health codes were only valid locally, but not across regions. Therefore, there is an urgent need for a unified health travel certificate, so the travel code came into being.
Travel itinerary Code is jointly launched by the Ministry of Industry and Information Technology and the three major operators of China Mobile, China Unicom and China Telecom. It can more accurately grasp the user's travel information, so as to confirm whether the user has been to medium and high-risk areas. It is very important that it can also find omissions and reports in time.
This mainly relies on three methods to locate mobile phones: base station positioning, wireless network positioning and GPS positioning.
The first is the location of the base station, which is familiar to everyone. If you want to make a phone call and surf the Internet, you need to do it within the coverage of the base station. In order to ensure smooth communication, operators will set up a base station every once in a while, so that when your mobile phone crosses from one base station to another, the travel code can know that your trajectory crosses from one place to another.
The second is wireless network positioning, which is simply wifi positioning. One thing that makes a router unique is the MAC address. Nowadays, most people's mobile phone wifi is on every day. No matter where they go, big data will collect information according to the MAC address of the router of wifi we used.
The last one is satellite positioning. Some remote areas have no base station coverage at all, let alone wifi. What should I do? This requires relying on satellite positioning. The GPS built into the smart phone will automatically dock with the satellite, and the satellite system can know the specific location of the user accordingly.