Tech Papers and Guides
Device Address and Activation by Personalization
When they join a network, devices are assigned a 32-bit ephemeral device address (DevAddr). A DevAddr is assigned during the join process for devices that join a network using the (preferred) over-the-air activation (OTAA) technique. However, some devices may have special requirements to effectively create a network session without joining the network over the air. These devices are activated by personalization (ABP) devices. If you are working with ABP devices it is important to understand that, like the DevEUI, the DevAddr is composed of two parts: the address prefix and the network address. The address prefix is allocated by the LoRa Alliance® and is unique to each network that has been granted a NetID.
Since device developers may not always know to which NetID their devices will be allocated, the LoRa Alliance has defined some developmental ranges for the DevAddr. Developmental systems should use the private/experimental network reserved with the AddrPrefix = 7’b0000000 or AddrPrefix = 7’b0000001. The remaining 25 bits of the NwkAddr can be assigned freely, if the DevAddr is not already assigned by the LNS that the device is joining.