Cell Site Location Information (CSLI)
Definition
Records held by a mobile network operator showing which cell towers a device registered with and when. Historical CSLI covers past registrations. Prospective CSLI (also called real-time CSLI or a tower dump) covers future registrations as they occur. Both require legal process in most jurisdictions.
- Full form
- Cell Site Location Information
- Historical CSLI
- Past tower registrations
- Prospective CSLI
- Real-time or future registrations, e.g. tower dumps
- Access requirement
- Legal process in most jurisdictions
- Held by
- Mobile network operator
Common questions
What is the difference between historical and prospective CSLI in practice?+
Historical CSLI is pulled from records already stored by the carrier and answers where a device was in the past. Prospective CSLI is captured going forward from the point of a legal order, effectively tracking a device's location as it moves.
Why does prospective CSLI usually need a higher legal threshold?+
Ongoing, real-time tracking is more intrusive than a historical records request because it monitors a person's movements as they happen, so many jurisdictions require a warrant or an equivalent higher standard rather than a simple records demand.
Related terms
- Geofencing Artifact
- A record generated when a device enters or exits a defined geographic boundary. Fitness apps, delivery apps, and smart-home apps create these...
- GNSS (Global Navigation Satellite System)
- The family of satellite-based positioning systems including US GPS, Russian GLONASS, European Galileo, and Chinese BeiDou. Mobile chipsets typically support multiple constellations...
- Significant Locations
- An iOS feature that records frequently visited places using a combination of GPS, Wi-Fi, and cell data. Stored in an encrypted SQLite...
- Tower Dump
- A legal demand directed to a mobile network operator for records of all devices that registered with one or more specific cell...
- Wi-Fi Probe Request
- A broadcast management frame that a Wi-Fi radio sends when scanning for known networks. The frame advertises the SSIDs stored in the...