Question: Beacon with no power

[laccf]

I'm using EID to my solution and sometimes a beacon gets their battery out of power. So i'm having problems with the sync with the Google Resolver, to resolve this beacon that stopped clocks it's clock. Anyone knows how much time it takes to the Google Solver solve this issue?

Here and here says respectively:

The Google Proximity Beacon API uses sightings of the beacon to infer each beacon's characteristic clock drift in order to ensure high reliability. The system is robust against power outages of several days, though re-synchronising the beacon clock's offset may take some time for longer outages.

The trusted resolver should implement resolution over a time window sufficient to allow for both reasonable clock drift and this type of power loss recovery.

So, i'm wondering if the google api is a trusted resolver, because i'm lossing lots of beacons and all the time that I loose a beacon I have to register the beacon again and set it up again.

[adriancretu]

If the beacon internally loses its registration clock offset and its Identity Key, you can consider it dead. Since the EID "resolving" is nothing more than a huge database, it's useless to try a "clock drift resync" (whatever that means) if the beacon is computing the new EIDs using an incorrect current timestamp (in hours, days, or years). To recover and restart EID beacon which lost power you'd need a few pieces of information:

• "cold" data: the registration clock, Identity Key, and exponent
• "warm" data: a synchronized method to get a correct relative time (for example the current correct time, which you could pass somehow into the beacon after a restart). You need this to compute the initial and continuous EID keys, because this is the same relative time base the EID "solver" will use to generate the future keys as well.

So my guess is that your problem is related to not being able to continue advertising of an existing EID beacon.