LoRaWAN 1.0.4 Specification in Depth For End Device Developers

The channel frequencies you use to send messages differ between regions. Find the channels to use for a given region in the ‘Band Channel Frequencies’ subsection for the region in Section 2 of the RP002-1.0.4 LoRaWAN® Regional Parameters specification.

The device should generate a pseudo-randomly sorted list of the channels available for its region and then iterate through each channel in this list with each transmission, as described in Section 3.7, ‘Avoiding Synchronous Behavior’ (page 16) of the TR007 Developing LoRaWAN® Devices V1.0.0. This minimizes the risk of multiple end devices broadcasting on the same channel, increasing the chance of messages reaching a gateway.

The network may request your end device to change the enabled channel list in the following circumstances:

• When an end device uses over the air activation (OTAA) to join the network, it may receive network parameters indicating the channels to use in the CFList field in the Join-Accept. Learn how to process the CFList field in section Step 3D: End Device Handles Join Accept of the End Device Activation Book.

• When an end device uses adaptive data rate (ADR), it may receive the LinkADRReq MAC command containing the Channel Mask (ChMask) field that requests an update to the channels to use when sending uplinks. Learn how to process the LinkADRReq MAC command ChMask field in section Convert and Validate Channel Mask Updates of the Implementing Adaptive Data Rate Book.

  Note

  The end device will eventually be required to re-enable all the dynamic channel plan default channels or all the fixed plan channels when following the ADR backoff procedure, as described in section ADR Backoff of the Implementing Adaptive Data Rate Book. ADR backoff allows the device to regain connectivity if circumstances in the environment change, resulting in the device losing contact with surrounding gateways.

• The NewChannelReq MAC command may be sent by the network server at any time to end devices in dynamic channel plan regions to create, modify, or disable channels. Learn how to handle the NewChannelReq and other MAC commands in section Handling MAC Commands of the Receiving Messages Book.

Whenever the enabled channel list requires updating, either following an update from the network or during the backoff procedure, the end device must update the list to include the specified channels, pseudo-randomly sort the list, and recommence iterating through the channels in the new list with each broadcast.