public int getTxPowerLevel() {
        return txPowerLevel;
    }
Returns the transmission power level of the packet in dBm. Returns {@link Integer#MIN_VALUE}
if the field is not set. This value can be used to calculate the path loss of a received
packet using the following equation:
<p>
<code>pathloss = txPowerLevel - rssi</code>
rxandroidble/src/main/java/com/polidea/rxandroidble2/internal/scan/ScanRecordImplCompat.java