The trip code is the communication big data trip card a code is also equivalent to the health code, is by the China Academy of Information and Communication Technology jointly with China Telecom, China Mobile, China Unicom three basic telecommunication enterprises to use the data received by the cell phone, through the user's cell phone is located in the location of the base station to obtain, for the country's 1.6 billion cell phone users free of charge to provide query services, cell phone users can be through the service, checking the I have been to all the previous 14 days of the city information.

When the trip code is obtained, the trip card will show the color according to your recent trip, a **** four kinds of green card, yellow card, orange card, red card.