I looked at the April Beacon app for Android. It has two options for transmission (tx) power : 0 dBm and -20 dBm. I suppose the transmission power directly affects how far the iBeacon signals can reach. My usage scenario requires differentiating between 2 meters aways on the same floor, and 2 meters away on a different floor, but the estimated distance is unable to differentiate between these two. This happens when the reader (a normal Android smartphone) is upstairs, the beacon is downstairs, but they are directly above/below each other.
I have tried both 0 dBm and -20 dBm, but it seems the signals from the beacon are almost of the same strength. Is there any possibility of further reducing the transmission power, so that without any obstacle, the beacon signals can reach at most 2 meters away? This will basically ensure the signals cannot reach the next floor, which is the behavior I need.