LoRaFieldTester – IGtti Webpage

During field deployment one of the most important questions is the signal strength and quality at that location. It will tell you about the robustness and stability of your device’s connection.

To answer this question you can check the coverage map in case of a public network, or you can install a private gateway close to the installation location or you can measure the signal. By measuring the signal you are sure of the answer, this is in my opinion the best option!

Yes, there are some field testers available in the market, normally not cheap.

This is where the fun starts… let’s build one!

The proposal is to use the same device board but connecting a display and request the link data from the network. This request can be made on each payload uplink, so you get a frequent downlink with up-to-date signal details. It is done via the LinkCheck command.

Interesting to note that this approach can be used for LoRaWAN and LoRaP2P, in this case following your own P2P protocol.

The following information can be displayed and evaluated on each location:

RSSI – The Received Signal Strength Indication (RSSI) is the received signal power in milliwatts and is measured in dBm. This value can be used as a measurement of how well a receiver can “hear” a signal from a sender.

SNR – The Signal to Noise Ratio is the minimum ratio of wanted signal power to noise that can be demodulated, i.e. it’s the ratio between the received power signal and the noise floor power level.

nbGateways – Additionally, for LoRaWAN it is also possible to show the number of gateways which received the last LinkCheck request. It gives you a good indication about the network redundancy at the location.

In the chart bellow you can find a general view about the relation between RSSI, SNR and what is considered good or bad connection.

Source: https://sensing-labs.com/f-a-q/a-good-radio-level/