Purpose of CoreRoutine Wi-Fi fingerprint lookups

Determine the purpose of the Wi-Fi fingerprint lookup requests sent by geod to Apple for CoreRoutine, which contain locations, nearby Wi-Fi access-point identifiers and signal strengths, and visit entry and exit times.

Background

The paper reports that geod sends Wi-Fi fingerprint lookup requests on behalf of CoreRoutine. Each request contains multiple locations, nearby access-point MAC addresses and signal strengths, together with the entry and exit times of a visit. Although the traffic is decoded and its contents are characterized, the function of these requests within Apple’s location-services architecture is not resolved.

References

The purpose of the request is not clear.

— Decoding What iOS Location Services Send to Apple: An LLM Is an Unreliable Analyst but a Useful Toolmaker  (2610.21597 - Leith, 15 Oct 2026) in Section 3.2.5, “Precise Location”