CITS4419 Sensor Networks Lab (week 4)

Concepts and Preparation

In this lab you will design and run some simulations and experiments to explore the effect of LoRa MAC parameters. You will build on experience from week 3 using Arduino Unos with a LoRa radio shield.

Before the lab you should review the lecture material and papers on LoRa from week 4.

Lab Tasks

  1. Download the LoRa simulator from github.com/websense/lorasimulator. This Python program enables you to explore the parameter space of LoRa physical layer. In particular you can compare energy use with channel path loss.
  2. Decide on an application setting for LoRa and choose appropriate energy requirements and expected path loss for channels in your application. LoRa is a long range technology so consider channels outside in the University campus.
  3. Use the LoRa simulator to search for the ``best" settings for each link (or group of links) for your settings. Since there are many unknowns about your channels you should investigate a range of parameters. Use graphs or tables to report your result. Summarise your main findings.
  4. What are the main uncertainties behind your estimates and what experimental data could you collect to reduce the uncertainty?

  5. Next you will program your LoRa radios to investigate the effect of your preferred LoRa settings in a real-world setting. Make a group of 4 people. Each group will need 2 Arduino Unos, 2 Dragino LoRa shields and 2 programming cables.
  6. Using
  7. Modify Dragino code to enable you to test several different LoRa parameter settings. Start with the code you developed last week or re-download prepared Arduino code from https://github.com/websense/LoraDraginoCode. Remember that if you use different Spreading Factors, and a reasonably low data rate, then different groups should not interfere, so you can use the central channel frequency.
  8. Record the RSSI and SNR, along with the LoRa parameters used and details of the channel for the setting(s) you measure. Note, there may be a problem with the LMIC.rssi and LMIC.snr reported by the LMIC library - to be advised.
  9. Record all relevant parameters you can think of. For example maybe use some of the week 2 nodes to record temperature and relative humidity. And use your phone to record the GPS co-ordinates of transmitter and receiver.
  10. Write a short lab report documenting the results of your experiments. We will discuss some professional standards for recording such measurements in the Wed PM lecture.
    • Describe your sensor network set up: the equipment used and your node positions.
    • Describe your channel and the LoRa setting(s) you experimented with.
    • Describe the RSSI and SNR values you observed. How much did these values vary? What do your results tell you about the communication channel.
    • Describe any other things that might have affected your experiment results. Record as many relevant parameters as you can: for example,
When you have completed your lab report, upload it to cssubmit (wk4 lab). Your report should be a single file in pdf format. Labs do not count towards your assessed marks but I will provide formative feedback on your lab reports. Submissions for the assessed project will be in a similar format.
UWA Department of Computer Science and Software Engineering