Understanding LoRaWAN

A field tester shows numbers: RSSI −108 dBm, SNR −6 dB, two gateways, SF9. Which of them is good and which is tight is not on the display. Many questions that reach us are about exactly that. Others concern the technology behind it: why does the network reply only rarely? Why does SF12 reach further than SF7? And why do no values arrive at all sometimes?

We have now gathered the answers in one place: the new Knowledge section.

Nine articles, from the basics to troubleshooting

1. LoRa and LoRaWAN: radio technique and network, how gateways and network servers work together, device classes.
2. Joining and security: OTAA and ABP, the keys of a device and why a gateway cannot read your data.
3. Frequencies in Europe and Switzerland: the EU868 band, its sub-bands and the duty cycle.
4. Spreading factor, data rate and airtime: what a higher spreading factor gains and what it costs in airtime.
5. The Things Network: the open community network, its fair use policy and the integrations.
6. Understanding the readings: RSSI, SNR, packet loss and gateways, and how to read them together.
7. What determines range: line of sight, height, Fresnel zone and buildings.
8. Troubleshooting: five questions in order when the tester shows no values.
9. Glossary: the terms briefly explained, with the sources.

With drawings

Most topics come with a drawing: how the airtime changes from SF7 to SF12, where the channels of The Things Network lie in the 863–870 MHz band, below which SNR a gateway can no longer decode a packet, or why a hill below the line of sight still attenuates the signal.

From reading to measuring

The knowledge helps to put readings in context; it does not replace a measurement on site. With a LoRaWAN field tester and fieldtester.io you check at every point whether a sensor gets through, and you see uplink and downlink as you do.

Missing a topic? Write to us; we keep adding to the section.