Say shake first. Shaking is just a trigger mode, which has nothing to do with positioning technology. The user just triggers a program through this action (the program uploads the user's location and matches other users), which is really just a gimmick.
Second, positioning. At present, I personally think that the mainstream of mobile Internet positioning is hybrid positioning, such as GPS+ base station +Wi-Fi hotspot. First of all, this hybrid positioning has priority, such as giving priority to GPS positioning (because GPS is the most accurate), and second, multiple positioning can make the results more accurate. These three positioning methods are probably like this:
1.GPS, the user's position can be determined by GPS satellite. The requirement is that it is outdoors, without obstacles and serious interference, and the most accurate error can be several meters.
2. Base station positioning or cell positioning, use mobile phones and several nearby base stations to determine the user's position, and use the speed of signals to determine the distance. When several distances intersect, the error can reach tens of meters to 100 meters in big cities, but it is far outside the wilderness.
3.Wi-Fi hotspot location only regards Wi-Fi hotspot as a base station, and it also has a unique ID. Someone (or technology company) collects the location information of wifi access points (how to do it? Actually, I don't understand it very systematically. For example, if you dare to take broadband IP, there is another stupid way, which is to drive around the street like Google Street View and query the coordinates recorded in the database of each hotspot. Mainly effective in big cities.
Finally, it is collocation. The WeChat you installed is called the client, and there is a server (cloud) in the remote computer room. After everyone "shakes", all their location information is uploaded to the server, and then the information of people who have shaken within a certain distance from you in a short time is pushed to you.