After more than 14 days, the corresponding location on the trip card will be automatically cleared, at which point a new trip card will be generated through the operator's query to see the latest results.

The three basic telecom companies use cell phone "signaling data", through the user's cell phone is located in the base station location to obtain, for the country's 1.6 billion cell phone users free of charge to provide the query service, the cell phone users can be through the service, query my first 14 days to all the cities and municipalities of information.

From 20:30 on January 8, 2021, the trip card will no longer mark the names of cities and towns containing medium- and high-risk areas in red, and will be changed to include medium- and high-risk areas in the bracketed remarks after the city name, with the remarks serving only as a travel reminder and not associated with health conditions.

Technological principle of communication big data itinerary card:

"Communication big data itinerary card" analyzes "cell phone signaling data", which is obtained through the location of the base station where the user's cell phone is located, and the process of collecting, transmitting, and processing signaling data is automated, with strict security and privacy safeguards. The collection, transmission and processing of signaling data are automated, with strict security and privacy protection mechanisms, and the query results are available in real time, convenient and fast.

The data of the "Communications Big Data Trip Card" can be used nationwide, which can truly achieve comprehensive coverage of the whole country, and can also be used to inquire about the international trips of one's domestic cell phone number.