The Itinerary Card 14 days counts from the day before you want to show or see the card to all the cities you have stayed in within 14 days.

Communication big data itinerary card, by the China Academy of Information and Communication Technology in conjunction with China Telecom, China Mobile, China Unicom three basic telecommunications enterprises using cell phone "signaling data", 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 to provide free query service, the service can be used to check their own cell phone users. Cell phone users can use the service to inquire about the information of all the cities and towns that they have visited in the previous 14 days.

The reason why the card doesn't show the track

1, this situation may be due to the poor signal of the surrounding environment, or signal blindness, this time no signal is a normal phenomenon, it is recommended to move around to look for a better signal, or leave the signal blindness.

2, may also be the phone comes with the system failure, at this time you can turn off the phone after restarting, so that the phone automatically connects to the network.

3, in addition, there may be a local mobile operator for some reason, such as thunderstorms, typhoons and other problems caused by problems with the signal transmission tower, this situation can only wait for the operator to repair the network connection.