Link Quality: general knowledge
SIGFOX provides a Link Quality indicator (LQI) based on:
- Received Signal Strength Indicator (RSSI)
- Number of stations that received a message (receiver redundancy)
- RC zone, due to the difference between the RCs (see Radio Configuration)
For zones RC1, RC3 and RC5:
| RSSI | Number of base stations | Link Quality indicator |
|---|---|---|
| -122dBm < RSSI | 3 | EXCELLENT |
| -135dBm < RSSI ≤ -122dBm | 3 | GOOD |
| -122dBm < RSSI | 1 or 2 | GOOD |
| -135dBm < RSSI ≤ -122dBm | 1 or 2 | AVERAGE |
| RSSI ≤ -135dBm | any | LIMIT |
For zones RC2 and RC4:
| RSSI | Number of base stations | Link Quality indicator |
|---|---|---|
| -114dBm < RSSI | 3 | EXCELLENT |
| -127dBm < RSSI ≤ -114dBm | 3 | GOOD |
| -114dBm < RSSI | 1 or 2 | GOOD |
| -127dBm < RSSI ≤ -114dBm | 1 or 2 | AVERAGE |
| RSSI ≤ -127dBm | any | LIMIT |
Number of base stations :
This is the number of base stations that received the message complying the RSSI threshold(s)
SNR :
Note : Sigfox does not recommend to use the SNR as an indicator of the quality of signal. Only refer to RSSI which is an objective indicator.