LoRaWAN device classes control when a sensor listens for incoming messages. Class A listens briefly after sending – then the radio is off completely until the next send. Class B listens on a schedule. Class C keeps listening almost all the time. Battery life goes down from A to C; response time goes down too.
Most sensors ship as Class A because it maximises battery life. The right class depends on whether the application needs to send commands to the device, and how quickly.
- Class A – opens two short receive windows only after each uplink; best battery life; downlink latency depends on how often the device transmits
- Class B – adds scheduled receive windows every 128 seconds (gateway beacon-synchronised); predictable latency for actuator applications
- Class C – receive window open continuously except when transmitting; mains-powered actuators only; lowest latency
In the catalogue: LoRaWAN devices