Mobile phone tracking

Technology

The location of a mobile phone can be determined using several complementary technologies. Modern phones typically use a Hybrid positioning system that combines these methods to provide the fastest and most accurate location possible.

Handset-based positioning

This is the most common method, where the device itself calculates its own position.

• GNSS / GPS: The phone uses a built-in receiver to calculate its precise location from signals broadcast by satellite navigation constellations (like GPS, GLONASS, or Galileo). This is the most accurate method when outdoors.
• Wi-Fi Positioning: In areas with poor satellite reception, such as indoors or in dense "urban canyons," the phone can scan for nearby Wi-Fi networks. It then calculates its position by cross-referencing the unique identifiers (BSSIDs) of these networks against a global, crowdsourced database of their locations.
• Fingerprinting: This technique records the "signature" of home and neighboring cell signal strengths at different points in an area. The device can then match its current signal signature to this database to determine its location.

Network-based positioning

This method relies on the cellular network infrastructure to determine the phone's location. The advantage is that it can be implemented non-intrusively by the service provider without any special software on the handset.

• Cell ID: The least accurate method, which uses the known location of the single cell tower the phone is communicating with. Its precision is low, especially in rural areas where cell towers are far apart.
• Multilateration: More advanced systems use the signal strength and timing from multiple adjacent cell towers to triangulate the phone's position. This is more accurate in urban areas where cell tower density is high.

Data transmission in modern applications

For any location-based service to function, the position data calculated by the phone (whether from GPS, Wi-Fi, or the network) must be transmitted to a server. The phone's built-in cellular modem sends this telemetry data over the mobile network (e.g., 4G/5G).

This "phone-as-a-sensor" model is the foundation for many modern on-demand services and is a key part of fleet digitalization. Applications for food delivery, courier services, and ride-hailing (like Uber or Lyft) rely on the phone's transmitted location data to function. The phone itself acts as the GPS tracking unit for the service's fleet management platform, allowing it to dispatch the nearest driver, provide customers with a real-time track and trace map, and calculate billing. The reliability of these services depends on this constant data connection; for example, the shutdown of older 3G networks required many commercial services to ensure their devices were 4G or 5G capable to maintain connectivity.

Operational purpose

In order to route calls to a phone, cell towers listen for a signal sent from the phone and negotiate which tower is best able to communicate with the phone. As the phone changes location, the antenna towers monitor the signal, and the phone is "roamed" to an adjacent tower as appropriate. By comparing the relative signal strength from multiple antenna towers, a general location of a phone can be roughly determined. Other means make use of the antenna pattern, which supports angular determination and phase discrimination.

Newer phones may also allow the tracking of the phone even when turned on but not active in a telephone call. This results from the roaming procedures that perform hand-over of the phone from one base station to another.{{cite web

Consumer applications

A phone's location can be shared with friends and family, posted to a public website, recorded locally, or shared with other users of a smartphone app. The inclusion of GPS receivers on smartphones has made geographical apps nearly ubiquitous on these devices. Specific applications include:

• Geo-fence specific locations of interest such as No Fly Zones
• GPS navigation and maps
• Locator apps like Find My Friends
• Dating apps like Grindr
• Recording a journey, for example to show a hiking accomplishment
• For quantified self purposes such as fitness tracking
• GPS drawing

In January 2019, the location of her iPhone as determined by her sister helped Boston police find kidnapping victim Olivia Ambrose.

Privacy

Locating or positioning touches upon delicate privacy issues, since it enables someone to check where a person is without the person's consent. Strict ethics and security measures are strongly recommended for services that employ positioning.

In 2012 Malte Spitz held a TED talk on the issue of mobile phone privacy in which he showcased his own stored data that he received from Deutsche Telekom after suing the company. He described the data, which consists of 35,830 lines of data collected during the span of Germany's data retention at the time, saying, "This is six months of my life [...] You can see where I am, when I sleep at night, what I'm doing." He partnered up with ZEIT Online and made his information publicly available in an interactive map which allows users to watch his entire movements during that time in fast-forward. Spitz concluded that technology consumers are the key to challenging privacy norms in today's society who "have to fight for self determination in the digital age."

China

The Chinese government has proposed using this technology to track commuting patterns of Beijing city residents. Aggregate presence of mobile phone users could be tracked in a privacy-preserving fashion. This location data was used to locate protesters during protests in Beijing in 2022.

Europe

In Europe most countries have a constitutional guarantee on the secrecy of correspondence, and location data obtained from mobile phone networks is usually given the same protection as the communication itself.

United States

In the United States, there is a limited constitutional guarantee on the privacy of telecommunications through the Fourth Amendment. The use of location data is further limited by statutory, administrative, and case law. Police access of seven days of a citizen's location data is unquestionably enough to be a fourth amendment search requiring both probable cause and a warrant.

In November 2017, the United States Supreme Court ruled in Carpenter v. United States that the government violates the Fourth Amendment by accessing historical records containing the physical locations of cellphones without a search warrant.

References

References

1. [http://to.swang.googlepages.com/ICC2008LBSforMobilessimplifiedR2.pdf "Location Based Services for Mobiles: Technologies and Standards“], Shu Wang, Jungwon Min and Byung K. Yi, [http://www.ieee-icc.org/ IEEE International Conference on Communication (ICC) 2008], Beijing, China
2. "Q&A on Location Data". Apple.
3. (2012-01-01). "CellSense: An Accurate Energy-Efficient GSM Positioning System". IEEE Transactions on Vehicular Technology.
4. [http://emits.sso.esa.int/emits-doc/1-5200-RD24-Mobile-positioning-using-wireless-networks.pdf Mobile Positioning Using Wireless Networks]
5. (2001). "IEEE VTS 53rd Vehicular Technology Conference, Spring 2001. Proceedings (Cat. No.01CH37202)". IEEE.
6. (August 3, 2023). "Will The 3G Sunset Leave Supply Chains In The Dark?".
7. "A common smartphone feature helped find missing woman - The Boston Globe".
8. "Brief for technology companies as amici curiae in support of neither party". Supreme Court of the United States.
9. (June 2012). "Your phone company is watching - TEDGlobal 2012". ted.com.
10. Fitzgerald, Britney. (25 July 2012). "Malte Spitz's TED Talk Takes On Mobile Phone Privacy Debate (VIDEO)". Huffington Post.
11. Biermann, Kai. (10 March 2011). "Betrayed by our own data". ZEIT.
12. Cecilia Kang. (March 3, 2011). "China plans to track cellphone users, sparking human rights concerns". The Washington Post.
13. D. Quercia, Ilias Leontiadis, Liam McNamara, Cecilia Mascolo, Jon Crowcroft (2011). [http://www.cl.cam.ac.uk/~dq209/publications/spotme.pdf SpotME If You Can: Randomized Responses for Location Obfuscation on Mobile Phones. ] ''IEEE ICDCS''
14. Xiong, Nectar Gan, Yong. (2022-12-02). "Chinese police are using cellphone data to track down protesters".
15. Spyropoulos, Philippos K.. (2009). "Constitutional law in Greece". Kluwer Law International.
16. Campbell, John. (2020). "The origins and development of the right to privacy". Edward Elgar Publishing.
17. "Chapter X, Fundamental Rights and Duties of Citizens, Article 128". [http://www.departments.bucknell.edu/russian/const/36cons04.html#chap10 ''1936 Constitution of the USSR''.] The inviolability of the homes of citizens and privacy of correspondence are protected by law.
18. Roxana Maria Roba. [https://old.upm.ro/facultati_departamente/ea/RePEc/curentul_juridic/rcj09/recjurid091_10F.pdf The Legal Protection of the Secrecy of Correspondence], ''Curentul "Juridic"'' ([https://web.archive.org/web/20150518070822/http://revcurentjur.ro/arhiva/attachments_200901/recjurid091_10F.pdf archived]), 2009, number 1, [[Tîrgu-Mureş]], [[Romania]].
19. {{cite court. (22 June 2018). link
20. {{cite court. (25 June 2014). link
21. {{cite court. United States v. Jones]]. (23 January 2012). link
22. {{cite court. (18 December 18, 1967). link
23. {{cite court. (1878). link
24. "Stored Communications Act (18 U.S. Code § 2703(d) - Required disclosure of customer communications or records)".
25. "47 CFR Subpart E - Privacy Act Regulations".
26. {{cite court. (3 July 1984). link
27. (23 June 2018). "Warrant Required for Cellphone Tracking Data". [[The New York Times]].
28. Keyaerts, K.. (2018). "United States ∙ Carpenter v US: Supreme Court Rules Police Need a Warrant to Obtain Cell-Site Location Information". European Data Protection Law Review.