The official blog of AirYarde, an Android app for tracking Wi-Fi signal.
Sunday, July 31, 2011
RSSI versus dBm / WifiManager versus ScanResult.
When AirYarde receives a RSSI change broadcast it stores the accompanying WifiManager.EXTRA_NEW_RSSI value. The Android developer reference says this is in fact the dBm value. Android also has an object called ScanResult that returns the "detected signal level in dBm. At least those are the units used by the TI driver." I updated AirYarde in my test environment to report signal strength using both methods. On my device the results were always the same.