Whose activity tracks can frequently appear in the hotel?

Hotel staff.

The action trajectory often refers to where a person comes from in a certain situation. This route is called the activity trajectory, which refers to the route that a person must take and has already traveled. Action Tracks are often used when looking for people or objects. You can check their movement tracks and discover where they have been.

The action track means that everything you did and where you went that day is recorded. What is related to the activity trajectories is "the intersection of activity trajectories", which means that within 14 days, the patient and the confirmed patient stayed together for 10 minutes in the same time and space grid.

For example, if a confirmed patient has been to a certain place within 14 days, and your trajectory in the past 14 days has intersected with him, whether it is a physical passing by or a drift in the communication signal, it may be detected. Identified as accompanied by time and space. After the system detects that you are a time and space companion with a confirmed patient, and you are a time and space companion among the risk groups, your health code will turn yellow.