Call Detail Records (CDRs) or Cell Site Location Information (CSLI) use cell towers to track a mobile device. Every time your phone connects to the network to send data, texts, or make calls, it logs a connection with nearby telecom antennas. [1, 2, 3, 4]

Here is how this data maps your phone:

How Tower Tracking Works

• Connecting Towers: Your phone routinely pings the tower with the strongest, clearest signal, not necessarily the closest one. [1, 2, 3, 4, 5]
• Sectors & Wedges: Towers are usually divided into “sectors” (often three, shaped like pizza slices), giving investigators an approximate wedge of where the device is located. [1]
• Movement Logs: As you move, your connection is handed off to different towers, creating a trail of which towers and sectors your device connected to at specific dates and times. [1]

Accuracy & Limitations

• General Estimates: Cell tower data provides a broad geographical area—it cannot pinpoint an exact address unless augmented with precise GPS data. [1, 2]
• Network Factors: Proximity is not the only factor; topography, weather, and tower maintenance schedules can alter which tower your phone reaches. [1]

Privacy and Law Enforcement

• Tower Dumps: Police can request a “cell tower dump,” which secures a list of all devices that communicated with a specific tower during a designated window of time. [1, 2]
• Stingrays: Law enforcement and certain attackers can use Stingrays (portable cell site simulators) that mimic legitimate towers to force your phone to connect, thereby revealing your exact whereabouts. [1, 2]
• Data Retention: Cellular network providers only retain precise historical location data for a short window (e.g., 7 to 30 days depending on the carrier). [1]