LoRaWAN

LoRaWAN is a low power wide area network (LPWAN) specification designed for battery-powered devices in the Internet of Things (IoT) that require long-range communication with infrequent data transmissions. It builds on the LoRa physical layer to provide a standardized MAC and network layer for large-scale IoT deployments.

Technology and topology

LoRaWAN uses chirp spread spectrum modulation to achieve long-range links and robustness in diverse environments. It employs a star-of-stars topology, where end devices communicate securely with gateways that forward packets to a central network server. Gateways are typically low-cost, provide wide coverage, and are connected to the network server via standard IP links. The network server then routes data to application servers or cloud services. The specification defines how devices join the network, manage data delivery, and handle security.

Devices, activation, and classes

LoRaWAN supports two activation methods: over-the-air activation (OTAA) and activation by personalization (ABP). Communication is organized around three device classes that trade off energy use and receive capability: Class A (default, energy efficient with receive windows after each uplink), Class B (scheduled receive windows with beacons), and Class C (almost continuous receive windows, higher power consumption). Class choice affects downlink latency and battery life.

Security and regulation

Security relies on AES-128 encryption for both network and application payloads, with separate session keys. Activation and session keys help ensure data integrity and privacy. LoRaWAN operates in unlicensed ISM bands and is subject to regional regulatory requirements, including duty cycle limits and listen-before-talk rules in some regions.

Standards and adoption

The LoRa Alliance develops and maintains the LoRaWAN specification, with multiple versions improving security, roaming, and interoperability. The technology is used by mobile network operators, city networks, and enterprises for applications such as smart meters, asset tracking, and environmental monitoring.