The Over-The-Air Activation (OTAA) is an on demand joining procedure for an end-device to join the LoRa network. The end-device initiates the joining procedure by sending the Dev-EUI and App-EUI to the network server; the network server returns the join accept signal along with the device ID (DevID). The end-device then derives the Network Session Key (NwkSKey) for MAC commands encryption and also derives Application Session Key (AppSKey) for application data encryption. The following figure shows the OTAA joining sequence.
Figure 1. OTAA Joining Procedure
