2 - Sending Messages
Messages sent from an end device to a network server via one or more nearby gateways are referred to as uplinks.
In this book, you learn the rules and best practices to follow when sending uplinks from your end device using the LoRaWAN® 1.0.4 specification.
Timing the Broadcast
Every application will likely have different items of application data that need to be broadcast on different schedules.
Firstly, choose a rough schedule for each item of data that needs transmitting, for example once every 15 mins, once every day, once every 7 days, or similar. Read more about timing in the Heartbeat Messages and Data Packet Transmissions sections of our Developing LoRaWAN-based Devices book.
Once you have a rough schedule in mind, you need to program this schedule into the end device. Do not simply set each message to broadcast at a fixed time or after a few seconds have elapsed; this can result in all your end devices broadcasting simultaneously, which will cause network congestion. Instead, use pseudo-random delays when identifying a moment to broadcast, as described in Section 3.7, ‘Avoiding Synchronous Behavior’ (page 16) of TR007 Developing LoRaWAN® Devices V1.0.0.
Note
You might also want to make a schedule end-user-configurable using a downlink, as discussed in the section Types of Downlinks of the Receiving Messages Book.