Understanding Cellular Data Usage in RAK LoRaWAN Edge and Soho Gateways

Cellular is the most common backhaul for LoRaWAN gateways due to its wide coverage, but it can quickly drive up costs if not managed properly. 

If you're using a RAK LoRaWAN Edge or Soho gateway with cellular connectivity, understanding how data is consumed is key to optimizing performance and reducing expenses. These gateways are designed for off-grid use and integrate with WisDM for remote access—ideal for field deployments using cellular.

This guide breaks down the main contributors to cellular data usage, how these gateways handle traffic, and how to optimize consumption without compromising network reliability.

What Affects Cellular Data Usage in RAK Gateway?

Figure 1: Typical IoT Architecture

The primary consumer of cellular data on a LoRaWAN gateway is LoRaWAN Network Server (LNS) communication. The gateway continuously forwards messages between IoT devices and the LNS, ensuring a smooth data flow between sensors and applications. While this process keeps the network operational, cellular data usage depends on several factors:

• How many devices are connected to the gateway
• How often these devices send uplinks and receive downlinks
  • Uplink messages: Sensor data transmitted to the gateway
  • Downlink messages: Commands and acknowledgments sent back to devices
• Logging and remote management settings enabled on the gateway

UDP vs. Basics Station vs. MQTT: Which Packet Forwarder Should You Use?

Cellular data usage in LoRaWAN gateways depends not only on how much data is transmitted but also on how efficiently it's handled. 

The packet forwarder is the component that handles communication between the gateway and the LNS. Each forwarder type has its own efficiency and network behavior.

Here's a comparison of the main forwarding protocols used in LoRaWAN gateways:

UDP Packet Forwarder (Legacy)

• Bandwidth-heavy: Sends raw LoRa packets directly to the LNS with minimal optimization.
• Frequent overhead: Requires regular status updates and acknowledgments, increasing data consumption.
• No encryption: Communication is unencrypted by default, which may raise security concerns.
• Use case: Simple deployments where legacy compatibility or minimal configuration is needed.

Basics Station

• Persistent connection: Uses WebSockets to maintain an open channel with the LNS, reducing overhead from repeated handshakes.
• Secure communication: Supports TLS encryption, adding minor overhead but improving reliability.
• Efficient messaging: Optimized for bidirectional communication—fewer unnecessary transmissions.
• Use case: Recommended for most modern RAK deployments, especially when cellular data cost is a concern.

MQTT Forwarder

• Lightweight protocol: Uses MQTT, a publish-subscribe system with lower overhead compared to UDP.
• Data control: Supports retained messages and reduced payload size, making it more bandwidth-efficient.
• Flexible reliability: Offers configurable QoS (Quality of Service) levels for message delivery guarantees.
• Use case: Ideal for cloud-based or scalable IoT applications needing flexible routing and minimal data footprint.

The table below summarizes the key differences between the three main LoRaWAN packet forwarders:

Choosing the right packet forwarder can significantly reduce data usage in bandwidth-sensitive areas like remote or mobile cellular networks.

• UDP is simple but not optimized, leading to higher data consumption.
• Basics Station and MQTT offer more efficient data handling, making them suitable for cellular deployments.

How Does WisDM Logging Impact Your Data Plan?

WisDM is a cloud-based device monitoring and remote management platform, allowing centralized access to logs, configuration, and firmware updates for WisGate Edge and Soho gateways. While essential for maintaining large-scale deployments, WisDM activity can add to data usage, especially over cellular.

Here are test results from a real-world scenario using a Basics Station forwarder and WisDM, with 10 nodes sending uplink packets every 10 minutes:

From these results, you can conclude that WisDM’s data usage varies by configuration:

• WisDM has minimal impact in basic configurations (about 0.36 MB per hour, or 9.23% of total traffic). 
• Log sharing increases usage slightly (0.41 MB per hour, 10.46%).
• Debug mode significantly increases traffic (1.33 MB per hour, 27.42%).

How to Reduce Cellular Data Usage in RAK Deployment?

To keep cellular deployments with RAK gateways efficient and cost-effective, consider the following practical strategies:

1. Select the Right Forwarder Protocol: Use MQTT or Basics Station over legacy UDP to reduce bandwidth use.
2. Monitor LNS Communication: Adjust message intervals based on how frequently devices send data to optimize transfer.
3. Limit Debug Logging: Enable debug logs only when troubleshooting to avoid excessive data usage.
4. Be Selective with Log Sharing: Share logs selectively to avoid excess data transfer.
5. Use Ethernet When Available: Minimize cellular expenses with a wired connection.

Final Thoughts

WisGate Edge and Soho gateways are well-suited for deployments that rely on cellular backhaul, offering flexibility and broad coverage in the field. However, without proper configuration, recurring data costs can increase over time.

By using efficient forwarders, managing logging and WisDM activity, and adjusting device communication intervals, you can minimize data usage while keeping your deployment reliable and cost-effective.

Todor Velev Experienced Technical Marketing and Support Specialist with a strong background in FAE, troubleshooting, and resolving customer issues. Passionate about cutting-edge technologies, including AI, big data, and IoT.