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Electronics => Beginners => Topic started by: Karamel on September 04, 2017, 03:13:00 am

Title: Bluetooth UUID Question
Post by: Karamel on September 04, 2017, 03:13:00 am
Hi,

I have a question about bluetooth technology. I can find UUID of any bluetooth devices with phone which runs my application.

My question is that how many phones can learn UUID of any bluetooth device at the same time?

Best Regards,
Karamel  ^-^


P.s: I can find UUID of any other devices. Paired or non paired doesn't matter. -> "I work non-paired mode"
Title: Re: Bluetooth UUID Question
Post by: Karamel on September 04, 2017, 04:26:51 am
Just think like that,

I have one beacon which has ble 4.0 and one billion phones.

Phones' bluetooth has opened and they run my app at the same time. (App only tries to find UUID)(Also phones are in the range)

How many phones will find UUID of beacon?

Note: I can find beacon's UUID without pairing.
Title: Re: Bluetooth UUID Question
Post by: stmdude on September 04, 2017, 04:07:59 pm
Your terminology is still vague at best.

I'm assuming you're talking about BLE "iBeacons". If you don't the rest of this post might be completely inaccurate.

iBeacons are one-way only. They just transmit an BLE advertisement packet blindly, and don't even listen for any packets coming back to it.
The phones just listen, and keep track of the UUID of the beacons they have received a packet from.

This means that your iBeacon could support an infinite number of phones, because, it simply is completely oblivious to if there's a phone (or a billion, for that matter) anywhere close to it. It simply doesn't even listen for a phone.

Then again, this _only_ applies to iBeacons. If you use another beacon protocol, this might not apply. If you're using the word "beacon" instead of advertisement, and actually connect the phone to the device (even without pairing), this is post is _completely_ wrong.
Title: Re: Bluetooth UUID Question
Post by: Karamel on September 04, 2017, 06:37:20 pm
I have no great information about bluetooth so, that's why I am talking like vague.

You can try or search that every beacons share their UUID and signal quality in dB. These informations are enough to solve my problem. I don't care about more but I wonder that how many bluetooth device can get these information at the same time?

I repeat my question again.

One beacon shares UUID and its signal quality. Besides, there are one billion listener phones in range. They have started to at the same time.
How many phone will find UUID and signal quality information of beacon?
Title: Re: Bluetooth UUID Question
Post by: stmdude on September 04, 2017, 07:47:55 pm
One beacon shares UUID and its signal quality. Besides, there are one billion listener phones in range. They have started to at the same time.
How many phone will find UUID and signal quality information of beacon?

Assuming you're talking about an _iBeacon_ type of beacon, all the phones will find the UUID. The signal quality comes from the phone itself, not the beacon, so they will all have that as well.
Title: Re: Bluetooth UUID Question
Post by: Karamel on September 04, 2017, 10:15:29 pm
Thanks for answer,

Isn't there any limit? I mean, one billion device can't learn its UUID at the same time, right? A little bit time must pass?

Actually, I searched this information in internet but I couldn't, unfortunately , find.  :-[