LoRaWAN: What is it?

What is LoRaWAN?

LoRaWAN (Long Range Wide Area Network) is a low-power wide-area network (LPWAN) protocol designed specifically for IoT applications requiring long-range communication with extended battery life. Developed by the LoRa Alliance, this open standard operates on unlicensed frequency bands (868 MHz in Europe, 915 MHz in North America) and can cover distances from 2 to 15 kilometres in urban areas, and up to 45 kilometres in rural areas with clear line of sight.

The technology comprises two distinct layers: LoRa (Long Range), Semtech's proprietary radio modulation based on Chirp Spread Spectrum (CSS), which handles the physical signal transmission, and LoRaWAN, the network protocol that manages communication between devices, gateways, and the network server. This separation allows great flexibility: different devices can use the LoRa layer with varied network implementations.

LoRaWAN distinguishes itself from traditional cellular networks (4G/5G) by its ability to transmit small data packets (a few tens to a few hundred bytes) over very long distances with extremely low power consumption, allowing battery-powered sensors to operate for 5 to 10 years without maintenance. In Belgium, public LoRaWAN networks (Proximus, The Things Network) and private networks cover a large portion of the territory.

Why LoRaWAN matters

LoRaWAN fills a critical gap in the IoT communications ecosystem, between short-range Wi-Fi/Bluetooth and energy-costly cellular networks. Its relevance manifests across numerous use cases.

• Exceptional battery life: LoRaWAN sensors operate for years on a single battery, eliminating maintenance costs related to battery replacement and enabling deployments in hard-to-reach locations.
• Extended coverage: a single LoRaWAN gateway covers square kilometres, significantly reducing the required infrastructure compared to Wi-Fi or Zigbee, which need relays every few dozen metres.
• Reduced infrastructure cost: unlicensed frequency bands eliminate cellular subscription fees, and LoRaWAN hardware (sensors, gateways) is financially accessible.
• Bidirectionality: unlike some LPWAN protocols such as Sigfox, LoRaWAN supports bidirectional communication, allowing commands to be sent to sensors (modify transmission frequency, update firmware).
• Native security: LoRaWAN integrates end-to-end AES-128 encryption (network layer and application layer), ensuring the confidentiality and integrity of transmitted data.

How it works

The LoRaWAN architecture follows a star-of-stars model. End devices, equipped with sensors and a LoRa radio module, transmit their data as radio frames on the 868 MHz band. These frames are captured by one or more gateways within radio range. Gateways are simple transparent relays: they receive radio frames and retransmit them to the Network Server via a standard IP connection (Ethernet, Wi-Fi, 4G).

The Network Server manages the LoRaWAN protocol: it deduplicates messages received by multiple gateways, verifies device authentication, manages adaptive transmission parameters (ADR - Adaptive Data Rate), and routes messages to the appropriate Application Server. The Application Server decodes the application data and transmits it to the business backend, typically via MQTT or HTTP webhooks.

LoRaWAN defines three device classes. Class A (the most energy-efficient) only opens receive windows briefly after each transmission. Class B adds scheduled receive windows (beacons) to reduce downlink latency. Class C maintains near-permanent listening, suited to mains-powered devices. The majority of IoT sensors use Class A to maximise battery life.

Concrete example

At Kern-IT, we deploy LoRaWAN sensors for use cases requiring extended coverage and long battery life. For a Brussels property manager, we installed LoRaWAN temperature and humidity sensors in several buildings spread across the municipality. A single gateway installed on a rooftop covers the entire property portfolio, eliminating the need for Wi-Fi connectivity in each building.

Sensor data transits through the LoRaWAN network to our network server (ChirpStack), then is routed via MQTT to our Django backend. Data processing, storage in PostgreSQL with TimescaleDB, and visualisation on KERN MAP provide the manager with a complete cartographic view of their buildings with real-time environmental metrics. Threshold breach alerts are sent by email and via the web application.

Implementation

1. Assess coverage: check LoRaWAN network availability in your area (Proximus LoRa, The Things Network) or plan private gateway deployment based on topography and distances to cover.
2. Choose sensors: select certified LoRaWAN sensors suited to your physical quantities (temperature, humidity, CO2, motion, water level, door opening) and environment (indoor/outdoor, IP67).
3. Deploy the network server: use ChirpStack (open source) or a managed service (The Things Stack, Actility) to manage devices, protocol, and data routing.
4. Configure MQTT integration: connect the LoRaWAN network server to your MQTT broker to transmit decoded data to your Django backend.
5. Develop the processing backend: implement MQTT consumers in Django to receive, decode, store, and alert on sensor data.
6. Optimise consumption: configure ADR (Adaptive Data Rate) and adjust transmission frequency to maximise sensor battery life while meeting business data freshness requirements.

Associated technologies and tools

• ChirpStack: open-source LoRaWAN network server, comprehensive and well-documented, ideal for private deployments.
• The Things Network / Stack: community LoRaWAN network and commercial platform for IoT application deployment.
• MQTT: lightweight messaging protocol used to transmit LoRaWAN data from the network server to the application backend.
• Raspberry Pi: used as a LoRaWAN gateway with a RAK or IMST radio concentrator, or as a local network server.
• Semtech SX1276/SX1262: LoRa radio chips integrated into sensor and gateway modules.
• CayenneLPP: standard payload format for LoRaWAN that simplifies sensor data encoding and decoding.

Conclusion

LoRaWAN is the protocol of choice for IoT deployments requiring extended coverage, long battery life, and controlled infrastructure costs. Its maturity, the richness of the available sensor ecosystem, and growing network coverage in Belgium make it an accessible and reliable technology. At Kern-IT, we combine LoRaWAN with our MQTT/Django/KERN MAP stack to deliver complete IoT solutions, from field data collection to cartographic visualisation, tailored to the specific needs of our clients in real estate, telecom, and smart building.