What does big data mean in the same spatio-temporal grid?

Big Data Same Space-time Network means that my phone number and confirmation number stay in the same space-time grid (the range is 800 m * 800 m) * * for more than 14 minutes, and the cumulative stay time of any number in recent 14 days exceeds 30 hours, and the found number is a space-time companion number. My green health code will turn into a yellow code with warning nature, and will be marked as a space-time companion by the system.

Before the time-space companion, people who investigated the risk of infection in COVID-19 were managed by close contacts. Comparing their definitions, we can find that the biggest difference lies in the further expansion of their spatial scope. The mobile phone number that collides with the track in an outdoor open space within a certain distance from the same base station within a specified time (for example, 10 minutes or more) is defined as a space-time companion that may be exposed.

relevant information

Persons with yellow health code and persons at risk associated with time and space who have received SMS reminders from Chengdu Public Security Bureau and Municipal Center for Disease Control and Prevention should immediately report to the community, and conduct two nucleic acid tests within 3 days, with the interval between the two nucleic acid tests being more than 24 hours. Please stay at home and don't go out until you get a negative result of nucleic acid.

Many places have introduced the definition and management methods of space-time caregivers, but the practices in different places are different. There is no unified definition and management method for "time-space entourage". In the information published in many places, time-space accompaniment, time-space intersection and time-space coincidence are all interpreted as a term, but the definitions published in different places are not uniform.