Improving the Performance of a Low Energy Wireless Sensor System: Better COTS DUST

Student: Praneil Raniga

Supervisor: Mark Schulz

Category: Engineering Thesis Project - Computer Systems

At the University of Queensland, Australia, department of ITEE, all Final year students must carry out a thesis topic in various fields, depending on their degree. These include Software, Hardware and Communications. Technology advancement has allowed wireless sensor systems to deploy in increasing numbers. Due to this large increase in the number of deployed sensor nodes, research is currently being conducted worldwide for communication methodologies utilising minimal power. Hence, the purpose of this thesis is to develop a product that utilizes minimal power while performing wireless communication. Hence the thesis topic: Improving the Performance of a Low Energy Wireless Sensor System: Better COTS DUST was formed.

Various number of researchers have also studied a range of techniques to improve the current consumption of wireless systems. One of them being Seth Edward-Austin Hollar. The goal of his thesis was to provide information on cubic inch autonomous sensor devices otherwise known as Commercial-off-the-Shelf-Dust (COTS Dust). One of the COTS Dust devices that were developed by Seth Edward-Austin Hollar, which was designed with James McLurkin, is the weC. It consisted of the Atmel AT90S8535 microprocessor and the RFM TR1000 transceiver chip, as well as various sensors. The current consumption for the weC mote, in active state, is 22.4mA. The objective of this thesis is therefore to improve the current consumption of this network sensor device, hence the sub-title, Better COTS DUST.

Improving the current performance for this system can theoretically be done in two ways. One way is improving an existing protocol, Software, and another way is to improve the designs of the Radio/Sensors, Hardware. However, to prove that the system has been improved, one of these variables must remain the same. That is, if improvement is focused on hardware, then software being implemented must be the same on both, the original and the improved hardware design. If improvement is made on software, then hardware must remain the same, and the original and the improved protocols are implemented on the hardware, then compared.

This thesis project has enhanced the systems current performance through the implementation of improved hardware designs. The figure above shows the improved hardware design, and is known as the UoQ (University of Queensland) mote.The software implemented on the hardware is the TinyOS. It is a software operating system that has been developed by UC Berkely. It is a small, open-source, and energy efficient protocol that has the ability to support large scale, self-configuring sensor networks. The source code and the software development tools are publicly available at the Berkeley web site.

Thesis Document (PDF)