Class A – Bi-Directional End Devices
- End-devices of Class A allow for bi-directional communications whereby each end-device's uplink transmission is followed by two short downlink receive windows.
Class B – Bi-Directional End-Devices with scheduled receive slots
- In addition to the Class A random receive windows, Class B devices open extra receive windows at scheduled times.
Class C – Bi-Directional End-Devices with maximum receive slots
- End-devices of Class C have nearly continuously open receive windows, only closed when transmitting.