Now is the digital age, cell phone can be said to be manually a long time to carry around. Therefore, the cell phone's mobile whereabouts track also effectively represents the person's whereabouts. Our cell phone, whether it is a smart phone or a traditional feature phone, as long as the insertion of the cell phone card, from power on to power off, always with the mobile, telecom, or Unicom's network base station to maintain a momentary contact. It's not that you only communicate with the base station when you make a phone call.

This constant connection is called signaling exchange. There is a clear location where the operator's base station is built, for example, on the upper floors of a neighborhood. According to your cell phone and base station communication contact can be roughly judged in which small area you have appeared in the area, the general city is about 300 meters within the scope of the rural is about 500 meters within the scope. This year the operator launched the principle of communication big data trip card service is probably so.

And other sources of whereabouts data can be more broadly included in your contact with public **** facilities, such as the use of public **** transportation, moving tickets in and out of the station are systematically recorded. Buses, subway stations, highway entrances and exits and so on. It can be said that in the era of digitization, intelligence, a person's whereabouts track are all traceable.