The RSSI indicator is a parameter that includes the total received signal strength for the radio channel width, including interference and thermal noise. It depends on the transmit power( EIRP) of the radio station and the distance between the radio station and the mobile station.
The RSSI value is measured by the connected stations in a wide variety of mobile radio systems and also in other radio-based transmission systems, and in the event of severe field strength drops it is used to switch to another radio channel.
The RSSI technique is used in 802.11WLANs, in Long Term Evolution( LTE) and in Bluetooth, among others. The field strength value comprises 1 byte and is used to indicate the field strength of the received hotspots. The reference quality value, the Reference Signal Receive Quality ( RSRQ), is calculated from RSSI and the receive field strength of the reference signal, the Reference Signal Receive Power( RSRP).
RSSI technology also has a practical application in the Passive Keyless Go( PKG) electronic locking system in automotive technology. This technology determines whether the car key is inside or outside the vehicle.