2. The Public Security Bureau uses the principle of mobile phone positioning: the location of the base station is determined by the signal received by the mobile phone.
The reason why there is a signal when using a mobile phone is because there are "base stations" within a certain range, and each base station has a fixed and unique number. As long as you make a phone call in this place, the information of the local base station will be available in the signal transmission system, which requires special technical departments and authorities.
3. Conditions for the Public Security Bureau to use mobile phones for location and related laws:
Chapter X Investigation on the Procedure of Public Security Organs Handling Criminal Cases
Section 10 Technical Investigation
Article 254 After filing a case, the public security organ may take technical investigation measures for the following criminal cases that seriously endanger society according to the needs of investigating crimes:
(1) Crimes endangering national security, terrorist activities, organized crimes of underworld nature and major drug crimes;
(two) intentional homicide, intentional injury causing serious injury or death, rape, robbery, kidnapping, arson, explosion, throwing dangerous substances and other serious violent crimes;
(3) Group, serial and trans-regional major criminal cases;
(four) the use of telecommunications, computer networks, delivery channels and other major criminal cases, as well as major criminal cases against computer networks;
(5) Other criminal cases that seriously endanger society may be sentenced to fixed-term imprisonment of more than seven years according to law.
The public security organ may take necessary technical investigation measures against the fugitive criminal suspect or defendant who is wanted or has been approved or decided to arrest.