[vlovich123]

Are the iPhones always tracking and reporting? Or are they just watching passively for the devices reported lost and only reporting the location to Apple of your own AirTags. The latter seems far more sensible. The battery cost of this is fairly trivial. Your phone is already capturing its location and reporting for FindMy. The incremental cost of attaching the AirTag’s location is minimal. To monitor BLE for a bunch of addresses is also minimal cost that’s typically predominantly done within the BT chip to avoid waking the SoC. At first glance there are some details that are unclear here in terms of how they scale this. For example, at Apple scale, the total size of lost AirTags is quite large, larger than what you can typically offload to a BLE chip. Similarly, the privacy protection features mean that BLE addresses rotate so just passively scanning wouldn’t be sufficient. My bet though is that that’s the work that was done - offloading all of this to the BLE chip in ways that are friendly to the HW capabilities. It’s also entirely possible they worked with their BT supplier to add the necessary low-level hooks to make that perform well and preserve privacy.