This solution leverages LoRaWAN®, a low-power radio technology standardized by the LoRa Alliance and optimized for battery-powered sensors. While this activity focuses on collecting data, LoRaWAN® is a bidirectional protocol that also supports sending commands to sensors.

The generic architecture of a LoRaWAN® network* is shown below. Uplink frames transmitted by the device are received by one or more LoRaWAN® Gateways and relayed to the LoRaWAN® Network Server via a backhaul network (e.g., IP over Ethernet or cellular).

Before transmitting sensor data, a process called Joining is required. During this process, the sensor authenticates itself with a Join Server (typically part of the Network Server) using its unique identifier (DevEUI) and secret key (JoinKey or AppKey). Importantly, the AppKey is never transmitted. Instead, it is used to derive two Session Keys:

• AppSKey: Encrypts the payload in subsequent messages.
• NwkSKey: Generates secure checksums to ensure packet integrity.

For this activity, understanding these technical details is not necessary—what matters is that all air-interface communication is securely encrypted and protected against replay attacks.