This tag has an U1 chip using Ultra Wide Band (UWB) which means that iPhones 11 and above also equipped with those chips will be able to locate those tags from 80m away with a +/-30cm accuracy. U1 UWB uses short pulses at 6.24GHz and 8.2GHz and positioning is done by combining time of flight (ToF) and angle of arrival (AoA).
I'm really curious how accurate this ends up being. Bluetooth location is one thing, but I've never seen bluetooth that can do anything more accurate than "X meters away"
These UWB chips claim to do "X meters away in Y direction". The direction aspect could be revolutionary if it works well. AirTags is the perfect use for it as well.
Our company experiments with indoor location tracking using UWB beacons. We've got a few demo kits from different vendors to test it out.
Overall, If you have a UWB receiver devices installed ~ every 4-5 meters (15 feet) you can triangulate beacon's position to a pretty precise degree (around 10 cm / 4 inches accuracy). You can even detect the height of a beacon above the floor.
However, triangulation is the key. Often we have to install extra receivers just to deal with big columns and barriers, sources of intense electromagnetism (like big electric engines or microwaves), or some materials (glass doors turned out to be a major problem, wooden doors - not so much).
I'm not sure how accurate a positioning can be with your phone acting as a sole UWB receiver. Clearly Apple can make it work sufficiently well for an everyday use, but it won't be as precise as they show in carefully constructed demos.
Compared to a dot on a map that usually just narrows it down to an entire building?
If the sound is muffled and you can’t hear it, this sounds like it could narrow it down to a specific room or maybe even area of a room. Which is a huge improvement.
I haven’t personally used a Tile before, but my impression was “you get what building it’s in, then have to search everywhere til it’s in earshot”
The finding app has an arrow on it, pointing you towards the signal. So maybe the map has only building-level resolution, but once you're in the building you just follow the arrow until it says you're standing on it.
im also super curious of this, i wanted to do a DIY angle of arrival necklace some time ago and last time i checked you required a whole mini antenna to achieve that!
I wonder if Apple will use this product as a Guinea Pig to test the possibility of building a device-to-device network over UWB. From what I've read (I'm not technical) this was tried sometime ago by a consortium but they gave up over the difficulties of sending communications over UWB.
Maybe Apple will manage a breaktrough by pouring money and brains over it like it did with M1?
Does anyone have any clue about whether other devices with a U1 chip will also be able to do that? (I'm thinking about people like me, who have an apple watch 6---which does have the U1 chip---but are a few generations behind on the iphone)
DP-3T admits now that the best solution is the Apple-Google one. They greatly contributed to the design of the A-G solution so kudos to them.
After reviewing this critical review of DP-3T, the only attack I see that applies to the Google-Apple solution is the replay attack. It can be fixed easily by the solution proposed by Prof. Serge Vaudenay of EPFL in Section 4.4 of https://eprint.iacr.org/2020/399.pdf. In a nutshell, send a tag along the ephemeral ID. This tag would be a message authentication code (MAC) computed with the ephemeral ID and a coarse timestamp of when it was sent using the sender's key, SKt. When Apple-Google sends out the SKt keys of the infected people to everybody, recipients will go through the ephemeral IDs they saw to look for matches. When there's a match, the tag will also be checked, i.e. does the tag I compute based on the timestamp when I received the ephemeral ID match the tag I received. If yes, then it was sent by this infected person. Otherwise, it's a replay attack and should be discarded.
I really hope Google and Apple will implement the proposed protocol from DP-3T and give audited and open source apps more control over how the contact tracing is done.
I agree. Ideally, the code will be embedded in the Android source code, which is open source. But more likely it will be an update of the Google Play Services, closed-source...
But the Cloud code should definitely be open-source. We can count on Google for that.
