The communication big data travel card service uses the base station data of China Mobile, China Unicom and China Telecom. In order to ensure continuous communication and achieve coverage without blind areas, the signals of base stations in the two places at the junction of administrative divisions may be cross-covered, and the query results may be biased.
Travel cards are updated every 14 days. Since the calculation of the first 14 days is completed in the background of the operator, there will be a one-day delay. In addition, the data will be updated after arriving in a new city for 4 hours, and the stay time will not exceed 4 hours and will not be recorded.