FortiExtender and Mobile Signal Strength Recommendations.Recommended signal strength (LTE/4G) mobile service modes.
Signal strength values are defined by a few different measurements which vary even more for different service modes (GSM/3G/LTE).
In 4G service mode, there are four relevant measurements:
–RSSI : Received Signal Strength Indicator is a negative value, and the closer to 0, the stronger the signal
–RSRP : Reference Signal Received Power is the power of the LTE Reference Signals spread over the full bandwidth and narrowband
–RSRQ : Reference Signal Received Quality is a type of measurement and it indicates the quality of the received reference signal.
–SINR : Signal to Interference + Noise Ratio (A minimum of -20 dB SINR is needed to detect RSRP/RSRQ). Indicates the throughput capacity of the channel. As the name implies, SINR is the strength of the signal divided by the strength of any interference.
Factor of signal values.
- Proximity to the cellular tower || Interference / competing signal || Weather
- Signal going through a cellular repeater || Physical barriers (buildings /hill/mountain/etc.)
| RSSI | ||
| RSSI | Signal strength | Description |
| > -65 dBm | Excellent | Strong signal with maximum data speeds |
| -65 dBm to -75 dBm | Good | Strong signal with good data speeds |
| -75 dBm to -85 dBm | Fair | Fair but useful, fast and reliable data speeds may be attained, but marginal data with drop-outs is possible |
| -85 dBm to -95 dBm | Poor | Performance will drop drastically |
| <= -95 dBm | No signal | Disconnection |
| RSRP | ||
| RSRP | Signal strength | Description |
| >= -80 dBm | Excellent | Strong signal with maximum data speeds |
| -80 dBm to -90 dBm | Good | Strong signal with good data speeds |
| -90 dBm to -100 dBm | Fair to poor | Reliable data speeds may be attained, but marginal data with drop-outs is possible. When this value gets close to -100, performance will drop drastically |
| <= -100 dBm | No signal | Disconnection |
| RSRQ | ||
| RSRQ | Signal quality | Description |
| >= -10 dB | Excellent | Strong signal with maximum data speeds |
| -10 dB to -15 dB | Good | Strong signal with good data speeds |
| -15 dB to -20 dB | Fair to poor | Reliable data speeds may be attained, but marginal data with drop-outs is possible. When this value gets close to -20, performance will drop drastically |
| <= -20 dB | No signal | Disconnection |
| SINR | ||
| SINR | Signal strength | Description |
| >= 20 dB | Excellent | Strong signal with maximum data speeds |
| 13 dB to 20 dB | Good | Strong signal with good data speeds |
| 0 dB to 13 dB | Fair to poor | Reliable data speeds may be attained, but marginal data with drop-outs is possible. When this value gets close to 0, performance will drop drastically |
| <= 0 dB | No signal | Disconnection |
RSSI for LTE is a calculated from several other signal related measurements:
RSSI = wideband power = noise + serving cell power + interference power.
For example, a 4G LTE modem might report an RSSI of -68 dBm(good, near to 0 better), but:
RSRP = -102 dBm ( No Signal / Near to 0 is better )
RSRQ = -16 dB ( FAIR to POOR / near to 0 is better )
SINR = -1.8 dB ( No Signal ) ( For good SINR reading, it must not be in negative value )
In this case, the signal quality is actually very poor. This could be due to the device being some distance away from the LTE transmitter. It’s also possible that something is interfering with the signal, such as a building or other obstructions between the device and the tower.
Example of Good LTE coverage in Fortiextender :
RSSI -56 dBm [> -65 dBm (Near to 0 is better) * refer RSSI table.]
RSRP -83 dBm [ >= -80 dBm (Near to 0 is better) * refer RSRP table.]
SINR 14.8dB [ 13 dB to 20 dB (must not be in negative value) refer SINR table.]
RSRQ -8 dB [ >= -10 dB (Near to 0 is better) * refer RSRQ table.]
FortiExtender and Mobile Signal Strength Recommendations.
In Fortiextender we can check connectivity log base on RSSI & SINR or RSRP & RSRQ.
Read more and more on this wiki. Thank you for your time. Have a nice day!