Where are the beacon information registered in Google's Proximity API available? - eddystone

Question

I know iBeacon only broadcasts UUID signal. What I'm reading about Proximity Beacon API is confusing. We must register:
Advertised ID (required)
Status
Stability
Latitude and longitude
Indoor floor level
Google Places API Place ID.
Text description
Arbitrary properties as key/value pairs
Does Eddystone broadcast all the information above, as shown on this image?

Answer 1

Beacons broadcast very little information themselves — typically only a Proximity UUID + major + minor (for iBeacons) or a BeaconID + transmission power (for Eddystone UID beacons).
The Proximity Beacon API is a service that allows you to "register" a beacon along with additional information for it. Some of this information, such as:
PlaceID
Building level
Stability
Lat/Lng
Description
Properties
are entirely optional are only for the registering beacon owner's own uses. You can choose to specify exactly where a beacon is with a lat/lng and a PlaceID, or you can skip these.
The Proximity Beacon API also lets you associate little pieces of data called "attachments" to your beacon. These are things that people can see when they run into your beacons in the wild. The content and format of these are entirely up to you.
So, if you want to register a beacon with the PB API, the only thing you MUST specify is the advertisementId.
For an Eddystone beacon, this will be 16 bytes (The BeaconID from the UID Frame) whereas for iBeacons, this will be 20 bytes (16 byte iBeacon Proximity UUID + 2 byte major + 2 byte minor).
Note that as per my answer to another question, what you upload to the register function for the beacon is a base64 encoded string representing the underlying BINARY data. So, get a Buffer or byte array representing the advertisement ID and then base64 encode that.

Answer 2

As you noted, the beacon itself only broadcasts its identifier—i.e., UUID + Major + Minor for iBeacon, and Namespace + Instance for Eddystone.
These additional fields that you register with Google's Proximity API are stored entirely on their server, and not broadcast by the beacon.
When you detect a beacon, you can read its identifier from the advertising packet, and use it to retrieve the additional data from Proximity API.
Imagine you have a beacon with identifier X. You upload the beacon's data to Proximity API, e.g., Advertised ID = X, description = "My beacon". Later, when your app detects that beacon, it can go to the Proximity API and say "give me data for beacon X", and that's how you gain access to the extra information, e.g., the "My beacon" description.
The image you've linked to is from a Proximity API tutorial I remember seeing on the Internet, and it's just a simplification, because strictly speaking, the beacon doesn't broadcast all this information, only the identifier. But this identifier is enough to fetch the extra data from Proximity API (providing you have Internet connection), so one can think about Proximity API as something that extends what you know about the beacon, and I think that's the reason why the image shows it this way.