RSS

Recevied Signal Strength (RSS) is often used interchangeably with RSSI, which refers specifically to the integer value indicating the strength, or with SS or signal strength, for the sake of brevity.

Sometimes also seen as Radio Signal Strength (not correct).

Wi-Fi
RSS is always given in negative values, by the WiFi specifications between 0 and -255, and recently more commonly between 0 and -100 (as with most or all Android devices). On Android devices, RSS is given in dBm, but by specification, the unit is an arbitrary relative indicator.

RSS is also an indicator in other technologies, such as Bluetooth.

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