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Radar: Ranging of iBeacons might fail if beacon is emitted on same device

This problem was encountered by me while research for chapter 7 of my book. Apparently other developers have encountered it as well as you can see from several questions on Stack Overflow:

So I am filing this as a dupe hoping for it to be fixed in iOS 8. Or if not, that it will become more visible to Apple.

Filed as rdar://17003408 and on Open Radar.



If you have an app emit an iBeacon as well as ranging might fail with CLError code 16.

Steps to Reproduce

  • Emit a beacon in an app via CBPeripheral
  • Range it via CLLocationManager

Expected Results

  • locationManager:didRangeBeacons:inRegion: should show this beacon

Actual Results

  • sometimes it works
  • sometimes you get locationManager:rangingBeaconsDidFailForRegion:withError: with code 16 “unavailable”.


I had this happen just now on an iPad Air and iPhone 5S, both running iOS 7.1.1. When I rebooted both the error no longer occurred.


In my testing I used separate apps on same device. i.e. start emitter app, then launch ranging app via Xcode. I am aware that beacon emitting is paused with the emitter app in background after a few seconds. Still ranging should not fail but return an empty array.

Supposedly earlier rdar://16761196 and rdar://15693657 describe the same issue.

Categories: Bug Reports

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