RSSI measures how strong a radio signal is when it arrives at a receiver. It is expressed in dBm – a negative number where less negative means stronger. -60 dBm is a strong signal; -120 dBm is at the edge of usability for LoRaWAN. The value is used to diagnose coverage and decide whether to adjust a device’s spreading factor or add a gateway.
RSSI alone does not tell the full story. A signal of -90 dBm in a quiet environment can work reliably; the same level in a noisy environment may not. Always check RSSI alongside SNR (Signal-to-Noise Ratio) when diagnosing LoRaWAN coverage issues.
- LoRaWAN typical range – -60 to -90 dBm is good; -100 to -115 dBm is workable at low spreading factors; -120+ dBm is marginal
- SNR – the noise floor relative to the signal; SNR above -7.5 dB is generally functional for LoRaWAN
- 4G/5G equivalent – RSRP (Reference Signal Received Power) is the equivalent measurement for cellular signals
- Gateway placement – if RSSI on multiple devices in an area is below -110 dBm, a gateway closer to those devices will help