So if I turn my phone off and get onto a bus or train with a tracking tag, other passengers will get an alert?
Also, the wording indicates that the tag needs to be marked as lost. But could that be used as plausible deniability -- that someone had stolen it -- by a person engaged in illicit tracking?
> The alert is not triggered immediately: it takes 8 hours during the day, 30 mins at night, and ...
But the warning system is by no means perfect. My family is split 50-50 between iOS and Androd ecosystems, and that's already enough to throw things off and get false positives semi-regularly.
Also, don't even ask the curriers how many alerts they get. Including airtags in valuable shipments is the de-facto standard nowdays.
Interesting research. Could have done with some motivation - why would you want to do this exactly? And it's a shame they couldn't get it to work with Google's network (in a non-awful way anyway).
Both let you transmit arbitrary data, but the custom setup here is a lot of overhead. Hubble gives you an SDK and lets you get back to building your device.
The clients can receive synchronisation data every minute and listen for a year on a coin cell. It’s broadcast, so a single beacon node can service hundreds of clients simultaneously.
BLE also can manage data connections over a kilometer and a half with reasonable (not great) antennas.
It’s not terribly fast, but modern radio protocols are opening up the possibilities. Lora and BLE are bringing the environment alive with communication.