1. How LoRaWan works?

How does it work?

LoRaWAN operates in the unlicensed radio spectrum, allowing devices to communicate with gateways without the need for cellular network infrastructure. It utilizes chirp spread spectrum modulation, which provides long-range communication, robustness against interference, and low power consumption.

LoRaWAN follows a star-of-stars network architecture, consisting of three main components: end devices (also called nodes or sensors), gateways, and a network server. Here's how they interact:

• End Devices: These are the sensor nodes or IoT devices that collect data from the environment or perform specific tasks. They are usually battery-powered and have limited processing capabilities. End devices can operate in two activation modes: Over-The-Air Activation (OTAA) or Activation-By-Personalization (ABP).

• Gateways: Gateways act as intermediaries between end devices and the network server. They receive LoRaWAN signals from nearby devices and forward them to the network server over an IP-based backhaul, such as Ethernet or cellular connections. Gateways can cover a large geographical area, allowing for long-range communication.

• Network Server: The network server manages the LoRaWAN network and controls communication between end devices and applications. It handles device authentication, security key management, data routing, and network-wide control. The network server can integrate with application servers or cloud platforms to process and store device data.

Communication Process

The communication process in LoRaWAN involves the following steps:

• Join Procedure: When an end device powers up or resets, it initiates the join procedure to establish a secure connection with the network. In OTAA mode, the device sends a join request containing its unique identifiers (DevEUI, AppEUI) and security keys to the network server. The network server verifies the device's credentials and assigns session keys for future communication.

• Uplink Data Transmission: After joining the network, an end device can periodically or event-drivenly transmit data to the network server. It packages the data into LoRaWAN frames and sends them using a specific data rate and frequency. The frames include payload data, device identifiers, security parameters, and error-checking codes.

• Downlink Data Reception: The network server can send downlink messages to specific end devices in response to their uplink transmissions or as commands. These messages can instruct devices to change settings, acknowledge successful reception, or request specific actions. The gateway receives the downlink messages from the network server and forwards them to the respective end devices.

Security and Scalability

LoRaWAN incorporates several security measures to ensure the integrity and confidentiality of data. It uses AES-128 encryption to protect payloads and control messages. End devices and gateways have unique identifiers and security keys, preventing unauthorized access and tampering. The network server manages session keys, enforces security policies, and detects potential attacks.

LoRaWAN is designed to scale efficiently, accommodating numerous devices in a single network. It achieves scalability by using adaptive data rate algorithms, which adjust the transmission parameters based on the signal quality and network conditions. This ensures optimal network utilization while maintaining long battery life for end devices.