LoRaWAN Network Server : working & Manufacturers

Introduction : The LoRaWAN Network Server (LNS) is the central intelligence of a LoRaWAN system, responsible for managing device sessions, security, and message routing between gateways, end devices and application servers.

Functions & Working of LoRaWAN Network Server

1. In the uplink, packet routes from device to Gateway to Network Server. It performs following tasks in the uplink direction.

• Packet Deduplication: Multiple gateways may receive the same uplink. LNS removes duplicates.
• Security Check: Decrypts packet using NwkSKey (network key).
• Integrity Check: Validates frame counters to prevent replay attacks.
• ADR (Adaptive Data Rate): Adjusts spreading factor, Tx power, channels for device efficiency.
• Forwarding: Sends application payload (decrypted with AppSKey) to the Application Server.

2. In the downlink, packet routes from Application server to Network Server to Gateway to End Device. It performs following tasks in the downlink direction.

• Encrypts payload with AppSKey or NwkSKey.
• Maintains downlink counters (AFCntDwn, NFCntDwn).
• Schedules downlink transmission in RX1/RX2 receive windows of devices.

3. Common functions : Device Activation, Roaming, Class Management, Network Policies etc.

The figure depicts position of LoRaWAN Network Server between Gateway and Application Server. Gateway is linked with end devices using LoRa wireless frequencies.

• End Devices send uplink packets to LNS who later validates, decrypts and routes.
• Gateways (via Packet Forwarder) act as radio bridges. The LNS communicates with them over UDP/IP (Semtech protocol) or MQTT.
• Join Server: Handles OTAA Join requests; provides session keys (NwkSKey, AppSKey) to the LNS.
• Application Server: Receives decrypted payloads from LNS, sends downlink application data back through LNS.

5 LoRaWAN Network Server Providers

Conclusion: By coordinating communication across devices and gateways, enforcing security through key management, and optimizing performance with features like ADR, the network server ensures that IoT applications can operate efficiently in diverse environments.