Service UUID advertised by non-connectable device

[Adam Heinrich]

Hello,

I would like to make an iOS app read BLE advertising packets (sent by nRF51) in background mode. The nRF51 sends ADV_SCAN_IND packets and is not connectable.

iOS method scanForPeripheralsWithServices forces me to include an service UUID into the advertising packet. From documentation:

Apps that have specified the bluetooth-central background mode are allowed to scan while in the background. That said, they must explicitly scan for one or more services by specifying them in the serviceUUIDs parameter.

I've included some random 128 bit service UUID into the advertising packet to have my device scannable by the iOS app. Is that legal when the service is in fact not supported (as the device is not connectable)?

I went through Bluetooth Core Specification and CSS, but I didn't find any mention.

Thank you,

Adam

[Eric Stutzenberger]

Hi Adam,

This is perfectly fine to do. Per the Bluetooth Spec, you are allowed to advertise a 128-bit custom UUID. In addition, you are essentially performing the Broadcaster role since the advertising packets are sent as non-connectable. iOS will report the advertising packets to you. In fact, this is very similar to how their iBeacon (and other Beacon) technology works. The main difference is that you are simply doing normal advertisements where Beacons have a specific Beacon packet structure.

Hope this helps,

Eric

[run_ar]

What else are you advertising? Have you considered using iBeacon technology instead (Since this can be received when the app is in the background)?

[Adam Heinrich]

I am including 20B of custom data (4B manuf. specific + 16B data) into scan response. I think I can't use iBeacon as the iOS API does not allow me to work with its raw advertising data.

[run_ar]

Yes, there are some limitations using ibeacon. But as EricS says you are allowed to advertise a 128bit custom uuid, so that is possible.

[Adam Heinrich]

Thank you!