Meshtastic Deployment: Architecture and Nodes

Meshtastic Network Architecture and Deployment for Field Operations

To establish communication between two teams of specialists over a distance of 80 km in rugged terrain, we chose Meshtastic based on LoRa. The main devices: HELTEC V4 as portable transmitters and repeaters, and D5L solar nodes without RAK4631. The project budget is 180,000 rubles for 25–30 users.

HELTEC V4 with ESP32-S3 and 2 MB PSRAM supports Store&Forward—storing and forwarding messages for users out of range. This is critical for mobile teams. Alternatives like LilyGo T3 or RAK4631 fall short in functionality and range.

Recommended Equipment:

• HELTEC V4: The core of portable nodes and repeaters. Full compatibility with flash memory for S&F, large community, affordable cases.
• D5L Solar Node: Autonomous power, charges even on cloudy days. Install HELTEC V4 instead of RAK4631 for enhanced capabilities.
• LilyGo T-BEAM: Versatile node with GPS, but overkill for messaging. Suitable as a backup option.
• Avoid: RAK4631 (low range despite energy efficiency), LilyGo T3 (expensive, few accessories).

We tested whip antennas F2. Cases from marketplaces ensure compactness and discretion.

Network Architecture and Range Testing

Actual node-to-node range is 850–900 m in line-of-sight (LoRa 900+ MHz). With a repeater at 4 m height—up to 3 km, but signal is lost in lowlands due to terrain.

Optimal setup:

• Repeaters in ROUTER mode every 3 km on elevated points.
• Additional ROUTER_LATE every 1.5 km in challenging areas for redundancy.
• Total of 11 repeaters for a 20 km route.

Portable nodes: CLIENT + CLIENT_BASE (two clients in parallel or a trio with a base). We disabled telemetry and geolocation to conserve bandwidth. Store&Forward on every second repeater prevents duplication.

Solar nodes operate autonomously: over 1.5 months, one failure due to mechanical issues, others without recharging.

Integration with an Internet Bridge

Satellite internet (128–512 Kbps) can't handle messengers (delays of 15–20 min). Mosquitto on a VPS solves the issue: lightweight messages transmit instantly.

Configuration:

• VPS: 1x 3.3 GHz CPU, 2 GB RAM, 30 GB NVMe. Load <30%.
• Empty ROOT TOPIC field in Mosquitto settings.

Cost: 4,500 rubles/6 months. Public servers aren't suitable due to privacy concerns.

Key Takeaways

• Store&Forward requires ESP32-S3 + PSRAM: Without this, the feature is unavailable.
• Repeaters every 1.5–3 km at height: Consider terrain for 900 MHz.
• Autonomy of solar nodes: HELTEC V4 in D5L runs for months without intervention.
• Mosquitto on VPS: Low requirements, instant communication over weak internet.
• CLIENT/CLIENT_BASE for portables: Minimizes traffic without telemetry.

The project provided communication without 220V infrastructure and expensive DMR repeaters.

— Editorial Team