Vicki LoRaWAN device periodically sends messages (keep-alive commands) to the server. The server can then send command to Vicki and the data will be received in the receiving windows, opened after each sent message, according to the LoRaWAN Class A devices protocol. The messages sent period is strict to the LoRaWAN duty cycle requirements. Vicki can send both confirmed/unconfirmed uplink messages depending on its configuration. We recommend configure Vicki for confirmed uplinks, since they provide message retransmission in case of not acknowledge of the sent message.