Trifork iBeacon Demo Lunch Talk

Trifork iBeacon DemoMobile Lunch 05.05.2014

Bluetooth Low Energy (BLE)

iBeacons• iBeacon is a BLE profile

specification formalised by Apple. It is not a standard.

• It can work on all devices that support Bluetooth LE, not just iOS.

• 2 primary use cases: Proximity and Ranging.

• Works indoors.

What is iBeacons

Bluetooth LE Support• Requires a Bluetooth LE chip. Only newer phones/

tablets has it.

• Windows: Phone 8.1 (?%), Lumia 520, 620, 625, 720

• iOS: 7.0+ (87%), iPhone 4s+, iPad 3rd generation+

• Android: 4.3 (14%), Samsung Galaxy S3+, Nexus 4+

iBeacon protocol• Advertisement bluetooth

package.

• Mac-address is spoofed on iOS.

• Proximity UUID: 16 byte UUID

• Major: 0 - 65.535

• Minor: 0 - 65.535

• TxPower: Signal Strength at 1m from iBeacon.

Detecting a iBeacon

• Can make drive-by-detection hard. Battery matters on both ends.

• Devices do not talk to each other. Phone simply listens to heartbeats from iBeacon.

• Scan time and intervals should be non-regular numbers, eg. scan period of 1.1s. instead of 1s.

Detecting proximity

• Just check for existence of the right combination of <Proximity UUID, Major, Minor>

• No guarantee that iBeacon is unique.

Detecting range• Hard problem. Many scientific papers

on the subject.

• Water blocks bluetooth signals. Guess what humans are mostly made of?

• Algorithm not known on iOS.

• Thus only rough estimates -> Immediate, Near, Far.

• Recommendation is to use relative range instead of absolute.

• “You know if you are close to an iBeacon, otherwise you don’t know anything”.

Code/SDK’s• Android doesn’t not provide a common API. Each

app must implement it.

• Androids Geofencing API doesn’t support iBeacons (yet).

• SDK’s exist that make it easy: Estimote, Radius Network, Gimbal (soon?).

• Demo app: https://github.com/cmelchior/trifork-ibeacon-demo

Keynote now has animated GIF Support :)

Lessons learned• Android Bluetooth stack is flawed. Crashes when it has

seen 2000 MAC’s: https://code.google.com/p/android/issues/detail?id=67272

• When monitoring, battery impact is small. It is still noticeable over a day however. Scan intervals matters!!!

• Ranging is very unprecise.

• Exit/Entry into a region can happen very frequently due to scans missing the iBeacon.

Links• http://en.wikipedia.org/wiki/IBeacon

• http://www.warski.org/blog/2014/01/how-ibeacons-work/

• http://stackoverflow.com/questions/18906988/what-is-the-ibeacon-bluetooth-profile

• http://stackoverflow.com/questions/20416218/understanding-ibeacon-distancing

• http://localz.co/blog/ibeacon-ble-hardware-commercial-comparison/

• https://github.com/RadiusNetworks/android-ibeacon-service

• https://github.com/Estimote/Android-SDK