LoRaWAN® networks primarily use the Aloha method for communication between end devices and their associated network servers. Using the Aloha method, end devices send data through a gateway to the network server only when one or more of their sensors notice a particular change in their environment or when some other event is triggered, such as a timer expiring. After the end device sends the uplink, it “listens” for a message from the network one and two seconds after the uplink before going back to sleep.