RSSI

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In telecommunications, Received Signal Strength Indicator (RSSI) is a measurement of the power present in a received radio signal.
The RSSI is indicated by a negative dBm value. This value relates to the signal strength of the cellular signal from the tower to the modem. The higher the number, the better the signal. The exact numbers vary between cellular carriers. However, -70 dBm and higher values usually equate to the modem being in an excellent coverage area. The closer to 0 dBm, the stronger the signal. There is a point at which trying to obtain more signal delivers diminishing returns, because the quality of the connection is defined by more values than just RSSI (you will find more information on the other measurements in the Mobile Signal Strength Recommendations page).
The RSSI is a relative value. Its measurement depends on the receiving device. For Teltonika-Networks devices, RSSI values represent these signal conditions:
RSSISignal strengthDescription>= -70 dBm-70 dBm to -85 dBm-85 dBm to -100 dBm-100 dBm to -110 dBm<= -110 dBm
Excellent Strong signal for best achievable speeds
Good Strong signal with good data speeds
Fair Fair but useful, fast and reliable data speeds may be attained, but marginal data with drop-outs is possible
Poor Performance will drop drastically
Very poor Connection may be lost
RSSISignal strengthDescription> -65 dBm-65 dBm to -75 dBm-75 dBm to -85 dBm-85 dBm to -95 dBm<= -95 dBm
Excellent Strong signal with maximum data speeds
Good Strong signal with good data speeds
Fair Fair but useful, fast and reliable data speeds may be attained, but marginal data with drop-outs is possible
Poor Performance will drop drastically
Very poor Connection may be lost