I am developing a BLE application for iDevices. And I know most of iDevices are belong to Bluetooth power Class2.
Class 1 - Maximum Power 100mW (20dBm) - Range 100 meters
Class 2 - Maximum Power 2.5mW (4dBm) - Range 10 meters
Class 3 - Maximum Power 1mW (0dBm) - Range 1 meter
I want to decrease the transmission power, which the range is about only 2 or 3 meters.
I saw the Android has some API which can set the TX level (AdvertiseSettings)
This isn't supported by iOS, at least in iOS 11. CBPeripheralManager doesn't allow you to modify the power setting. Even if it did, you'd have no certainty that it would be honored, since there may be other apps also advertising at the same time. Apps don't get exclusive access to the Bluetooth system.