LoRa Range Test from Mont Bessou (Corrèze, FR)

    “Here are the real-world propagation results from my repeater installed on Mont Bessou (alt. 976 m) in Corrèze - France.
    The node uses an Ebyte E22-400T22D LoRa transceiver running at 2400 baud and feeding a simple 2 dBi antenna (Retevis 5/8 lambda)

Test setup

Repeater on the summit at the GPS position LAT 45.568737,  LONG  2.212755 ; The receiver is the communicator with a 2 dBi antenna with the same LoRa module. 

The repeater was installed at the summit of Mont Bessou. The receiver was my handheld LoRa communicator, equipped with a small 2 dBi antenna.

I drove away from the repeater along accessible roads. Using GPS, I monitored the distance from the origin.

At each test point, I attempted to establish a link by sending a message from the communicator. If the message was successfully echoed by the repeater and displayed back on the communicator’s screen, I logged it as a successful transmission.

For each confirmed link, I recorded two values from the E22 module:

• the RSSI (Received Signal Strength Indicator)

• the ambient noise level
  (both values read from the module’s internal registers: 0×01 and 0×00, respectively)

    According to the E22 docs: dBm = –(256 – raw).
    Both RSSI and noise share this scale, so SNR [dB] = RSSI dBm – Noise dBm.

Plots
RSSI & noise vs distance and  SNR vs distance

Conclusions from the Propagation Graphs

The field test confirms that a LoRa repeater placed at a high point like Mont Bessou can sustain a long-distance link even with modest hardware and low RF power.

Key takeaways from the plots. The measurements confirm that even with a basic E22 module configured at 2400 baud and a small 2 dBi antenna, the repeater installed at the summit of Mont Bessou can maintain a reliable link up to 40 km — without a single lost message.

• The weakest signal observed (–88 dBm at 31 km) remains 49 dB above the declared sensitivity (–137 dBm), which means the link margin is extremely comfortable.

• The SNR stays positive across the entire distance. Even at the furthest point, with an SNR of +1 dB, there is still 13 to 16 dB of headroom before reaching the theoretical demodulation threshold (–12 dB to –15 dB for spreading factors SF9/SF10, which are likely used by the module — though Ebyte provides no clear details on this).

• The measured signal attenuation slope (about 6 dB per doubling of distance) closely matches that of a free-space propagation model. In ideal line-of-sight conditions, two additional doublings suggest a possible range of 60 to 80 km, or even up to 100 km on a clear ridge-to-ridge path.

These surprisingly good results are actually easy to explain: the transmission site is elevated, the 433 MHz band suffers less attenuation than 868 MHz, and the rural Corrèze region offers very low RF noise. Additionally, all test points were chosen to be free of nearby vegetation, clearly facing the repeater, and often positioned on elevated ground.

I didn’t push beyond 40 km for practical reasons: I was already quite far from the summit, and I wanted to keep the return drive reasonable (crossing the Dordogne valley is slow).
That said, the repeater should remain fully operational with negative link margins down to around –12 dB, which suggests significant additional range potential.

Not bad at all for such a simple setup.