How does Unicom check the reply information of roaming places?

Personal tracking has proved to be a "roaming query" service opened by large operators. This new initiative is a public welfare service provided to the owners on the premise of ensuring information security, relying on the operators' own big data capabilities. You can send a short message to the service provider to get the track of your mobile phone in the last month, which can be used to help prove whether you left the city or came back from other places in the last month. But whether to prove your trajectory in real life needs to be verified by relevant departments again. Operator's reminder: this service is a public service, and roaming information is for reference only, not as the final judgment basis.

The mobile phone sends "the last four digits of CXMYD# ID card" to 100 10 to inquire about the information of domestic roaming places in the past 30 days, which is convenient for rework and auxiliary investigation. Free inquiry per person per day 10 times. China Unicom's roaming query service has been launched nationwide.