Beacon ranging vs BLE scanning

Question

I was trying to understand the difference between Beacon Ranging and BLE Scanning. From what I understand, beacon ranging uses BLE scanning to find the beacons. On top of that it calculates proximity of beacons using the signal strength(which I do not need). I just need to detect the beacons(similar to beacon monitoring). I am not using beacon monitoring because of the Always permission requirement in IOS. I know that beacon monitoring is highly optimised as compared to ranging, but I wanted to know how ranging compares to BLE scanning.

• Can i use BLEModule.scanForDevices(UUID) in place of CLLocationManager.startRangingBeacons(region) to detect beacons? If yes, can I get callbacks in similar fashion when beacon is detected?

• Are there any downsides of doing this in terms of battery performance or detection time, etc.?

  Note that I am willing to make do without proximity information(distance from beacon).

Also, a related question:

• Can beacon monitoring be used in foreground with WhenInUse permission in iOS?(I found mixed views on this in my initial investigation)

Answer 1

You cannot use Core Bluetooth scanning to detect an iBeacon. You must use Core Location and monitor a CLBeaconRegion to discover iBeacons.

Having discovered a beacon you do not need to range it.

As stated in Apple's documentation

Important

Apps must have always authorization to use region monitoring, and they must be configured with the Location updates background mode to be launched.

Even if you only want beacon notification when your app is in the foreground you must request always permission.