Chapter 6: Basic Field Testing

Field Testing Guide for Doodle Labs Mesh Rider Radios

Purpose: To assess radio performance in real-world conditions, measuring range, throughput, latency, and link stability.

Setup Requirements

• Hardware:
  • Mesh Rider radios in a protective, field-friendly housing (preferably metal for heat dissipation)
  • Tablets (Android or Windows) for mobility or laptops for data handling
  • Antennas appropriate for operational frequency (Doodle Labs Recommended Antenna Matrix​)
  • Battery Packs or reliably power source for radios & computers
• Software:
  • SSH client for radio management
  • iperf3 for throughput testing
  • ping for latency measurement
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  • Network Configuration

• Set up a simple point-to-point or mesh network depending on your needs:
  • Point-to-Point: Use a Wearable radio and a mini-OEM radio connected via Wi-Fi or USB.
  • Mesh: Configure multiple nodes using batctl o to view routing information and node connectivity.

Testing
Throughput Testing:

• Run iperf3 -c <server IP> -t 30 -i 1 to test TCP throughput.

  • Use UDP mode with -u -b 5M to simulate stable data flow and measure packet loss.
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• Latency Testing:
  Perform latency checks with ping <IP address> -i 0.2 -s 250 -Q 0xC0 for high-priority packets.

  • Record round-trip times, noting any high-latency intervals that may indicate interference or distance limits.
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• Range Testing:

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    Initial Setup

    • Place the two radios (e.g., Wearable and Mini-OEM) at a starting position approximately 5 meters apart in an open, line-of-sight area.

    
    Establish Baseline Connectivity:

    • Start with a basic connectivity check using ping to ensure both radios are communicating.
    • Run a quick throughput test using iperf3 to establish baseline performance metrics at close range.

    Incremental Distance Testing:

    • Gradually increase the distance between the two radios in increments of 10 meters.
    • At each distance, run a 5-minute iperf3 test and record metrics such as throughput, packet loss, and latency.

    Monitor Signal and Connection Quality:

    • After each distance increment, check signal quality using iw dev wlan${PHY} station dump
    • Record RSSI (signal strength), link quality, and any packet loss observed.

    Identify Maximum Range:

    • Continue increasing the distance until you notice significant packet loss, increased latency, or a drop in throughput below acceptable levels for your application.
    • Recommended End Point: The maximum effective range is reached when throughput drops below 1 Mbps or packet loss consistently exceeds 10%.

    Record Environmental Factors:

    Place the two radios (e.g., Wearable and Mini-OEM) at a starting position approximately 5 meters apart in an open, line-of-sight area. 
    • Note any environmental elements that may impact the results, such as terrain, weather conditions, or obstructions.

Environmental Considerations

• Antenna Positioning: Ensure antennas are mounted with adequate spacing to avoid mutual interference.
• Interference: Avoid high-density areas with significant Wi-Fi or RF noise, as this may affect link stability and throughput.
• Fresnel Zone: Ensure partial line-of-sight clearance to avoid link degradation due to reflections or blockages.

Performance Monitoring
Signal Quality: Run iw wlan${PHY} station dump to measure RSSI and other signal metrics.

• Route Stability: Use batctl o to monitor mesh routes and detect changes due to movement or signal fluctuations.
• Airtime Utilization: Monitor sysutils activity to understand how much of the available spectrum is being used.

Optimization Tips
Channel Bandwidth: Use the widest bandwidth that doesn’t exceed the environment’s noise floor for maximum throughput.

• Modulation: The radio may auto-adjust modulation rates; maintain stable antennas and orientation for consistent rates.
• Environmental Tests: Check performance over reflective surfaces (e.g., water) to understand potential multipath effects.