CITS4419 Sensor Networks Lab (week 2)
Concepts and Preparation
This lab is designed to demonstrate the end-to-end process for sensor network deployments.
You will deploy sensor nodes and a gateway, collect some data, and document the experiment.
Before the lab you should review the lecture for week 1 and read The hitchhiker's guide to successful wireless sensor network deployments (SenSys 2008).
Both are available from the CITS4419 unit web page
- Choose a partner and get a climate sensor nodes (a Mannheim temperature-humidity sensor).
Put batteries into the climate nodes and choose a measurement position.
Record the details of your sensor (its ID and what is on the node) and also
document the position where you deploy it.
- Choose a receiver node and connect it into a USB port on your computer. Or you can use a Raspberry Pi if you prefer.
There are only a few receivers so groups will need to share.
Start a terminal reader program such as Putty, TeraTerm or screen (on Macs).
Set the baud rate to 9600 (or 115200 on one receiver - check the label).
Then listen on the usb port for incoming messages.
- Once you have the receiver working, restart it and save incoming messages to a file.
- Once you have gathered a reasonable amount of data,
download the data file(s) and analyse the messages you received.
Write a lab report for your deployment covering the following points.
- Document the sensor network deployment: describe the equipment used and all node positions.
- What is the format of the packets received? What type of measurement do you think each column is reporting?
- Describe the main characteristics of the temperature and humidity time series (eg. period, min, max, variability, smoothness)?
- How much variation is there for the temperature and relative humidity between different positions in the building?
- What range of channel receive signal strengths are seen? RSSI is the penultimate negative figure. It is measured in dBm.
- What is the transmission range of the sensors? Try to move a sensor to a range where it can not be heard. Then move closer until the first distance it can be heard.
- Characterise any correlation you can observe in the relationship between distance and signal strength?
- Suggest which features of the building might affect the quality of the communications channel?
Department of Computer Science and Software Engineering