Chapter 4: Bench Testing

Bench Testing Guide for Doodle Labs Mesh Rider Radios

Purpose: To test the Mesh Rider radio’s baseline performance in a controlled environment, assessing sensitivity, connectivity, and link stability without interference from environmental factors.

Setup Requirements

• Hardware:
  1. Mesh Rider radios
  2. Laptop or desktop (Windows or Linux preferred for data capture)
  3. RF attenuators (20-60 dB recommended to prevent radio overloading in close proximity)
  4. RF cables (to connect radios directly, avoiding external signal interference)
  5. Thermal management (use a metal enclosure or heatsink)
• Software:
  1. SSH client for remote radio management
  2. iperf3 for throughput testing
  3. ping for latency assessment

Physical Setup

For the OEM, Mini-OEM, and Nano-OEM form factors, we recommend designing a simple housing for the radios for field and even bench usage. The housing will make it easier to connect your PC or Smart Device, and hook up antennas, without the risk of damaging the radios (e.g. ESD, or mechanical damage). An example of how you could design a simple box is shown in Fig. 1.

Fig. 1 Field testing box

When designing your box,

1. 1. Use a metal box which can act as a heat sink.
2. 2. Use a thermally conductive adhesive tape to mount the radio to the box, or use a thermal pad or paste to ensure good thermal contact between the radio and the box.
3. 3. Ensure there is sufficient slack on internal cabling, but secure longer cables to the chassis to prevent excessive shaking.
4. 4. Ideally, antennas should be separated as much as possible for maximum diversity.

Testing Procedure

• Throughput Testing with iperf3:

  • Start the iperf3 server on one computer connected to a radio.
  • Use commands such as iperf3 -c <server IP> -t 10 -i 1 to measure maximum throughput over a 10-second interval.
  • For UDP testing, set a fixed bandwidth and packet loss monitoring with iperf3 -c <server IP> -u -b 5M -t 60 -i 1.
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• Latency Testing with ping:
  Execute ping <IP address> -i 0.2 -s 250 -Q 0xC0 to set up a high-priority DSCP flag for low-latency packet transfer.

  • Monitor round-trip times to assess link stability and responsiveness.

Metrics to Monitor

• Signal Strength: Use iw wlan${PHY} station dump to check RSSI values. Values above -70 dBm are ideal.
• Data Rates: The transmit and receive bitrate (MCS rate) indicates link quality and stability.
• CPU and Airtime: Run cat /proc/loadavg for CPU load and sysutils activity for network airtime usage.
• Link Metrics: Real-time link metrics can be viewed with ubus listen linkstate
• See the Link Status Log section below for more details.
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Tips for Optimal Results

• Avoid RF saturation by maintaining proper attenuation and monitoring signal strength.
• Use a stable power source to avoid fluctuations that may impact performance.
• Keep radios in shielded environments or RF isolation boxes for consistent testing conditions.

Link Status Log

The Link Status log utility is a tool designed to log important link quality metrics in the network. This service, once enabled, runs in the background on the radio and creates a log line every 2-3 seconds. This service is useful for analyzing, troubleshooting, and optimizing the Doodle network. To turn on the Link Status Log, navigate to Advanced Settings>Services>Link Status Log and check "Enable Link Status Log", followed by Save and Apply.

Note: The Link Status Log, by default, is not persistent. The archive must be downloaded before power cycling the radio.

For more detailed information, visit our <Link Status Log Guide>