NB-Fi network quality indicators
SNR (Signal to Noise Ratio, the ratio of received signal power to noise power, expressed using the logarithmic decibel scale, in dB) and RSSI (Received Signal Strength Indicator, the total power received by the receiver signal, measured in dBm) are the quantitative indicators of signal quality. These indicators are displayed on the messages page at the Head End System of the NB-Fi Server.
RSSI is the usable strength of radio waves, expressed in decibels between 0 dBm (strongest) and -150 dBm (weakest). Smaller negative numbers represent a cleaner/stronger signal.
SNR is a measure that compares the signal level to the amount of noise present in the medium of transmission. The larger the SNR is, the better it is. A stable signal can be considered with an average SNR of 30 dB or higher.
| SNR level | Description |
|---|---|
| 0 - 20 Signal-strength icon without bars in the MDM system |
Very weak signal |
| 21 - 30 Signal-strength icon with 1 bar in the MDM system |
Weak signal |
| 31 - 40 Signal-strength icon with 2 bars in the MDM system |
Average signal |
| 41 - 50 Signal-strength icon with 3 bars in the MDM system |
Good signal |
| 51 - 60 Signal-strength icon with 4 bars in the MDM system |
Very good signal |
| >60 Signal-strength icon with 5 bars in the MDM system |
Excellent signal |
The average SNR normalized to the data rate (NSNR) is available at the modem information page at the Head End System of the NB-Fi Server.