2.3.3 Class C End-Devices
The class C end-devices have nearly continuously open receive windows, only closed when transmitting. Class C end-device will use more power to operate than Class A or Class B, but they offer the lowest latency for the server to end-device communication.
For more detailed information on LoRaWAN protocol and LoRa technology, refer the LoRaWAN specification documents available with LoRa Alliance.