Monday, 28. June 2010 28.06.10 12:00 Age: 7 Jahre

Achieving maximum coverage
Project team FLYNET develops prototype for flying wireless sensor network

By: Katharina Bätz, English translation: Katrijn van Oudheusden

Hermann Simon Lichte and Juniorprofessor Dr. Hannes Frey (r.) holding a Quadrocopter (Photo: Katharina Bätz)

Paderborn, Germany. Originally, sensor networks were developed as early detection systems in the military to monitor pipelines or country borders. Today, networks consisting of a number of wireless sensors that communicate by radio to generate data, are absolutely necessary in applications such as environment monitoring, traffic control, and logistics.

At Paderborn University, wireless sensor networks (WSN) are well-known. The Institute for Computer Science has been working on a flying WSN since the winter of 2009. Junior Professor Dr. Hannes Frey, Hermann Simon Lichte, research assistant, and nine students of computer science and engineering, have set themselves the goal of positioning the sensor nodes in such a way as to maximize the area covered in the air, while at the same time avoiding isolation of knots in the network.

At the moment FLYNET has two such sensor nodes, called quadrocopters. “They have been developed in the last few years and we are definitely not the only group to work with them”, says project leader Hannes Frey. “Our goal is not pursued by anyone else though”, he goes on to clarify the uniqueness of the project.

In wireless communication the intended areal maximization is accompanied by the problem that the signal is not always very reliable. “The larger the area covered by the quadrocopters, the higher the likelihood that the transmission of data between sensor and receiver will be disrupted”, explains Frey.

To level out the high fluctuation between well-received and disrupted direct signals to the central data receiver, the project team is working on cooperative transmission methods. This means multiple nodes simultaneously receive the signal sent by the one node that needs to be transmitted to the central receiver. In this way, a possibly unreliable direct signal transmitted by one node can be “heard”, supported and improved by multiple other nodes, making the signal more reliable. “In our field work we want to show that we are not only capable of maximizing the distance between two copters, but that we can simultaneously keep the quality of the transmission the same”, is what Frey mentions as another goal of his group. The research team uses an embedded Linux board with W-LAN for the communication between the nodes.

Although the summer semester is currently ending, this does not mean the project will be put on ice, according to Junior Professor Frey. “In the next semester we will continue our research”, he says, showing satisfaction with the results so far. “The students are highly motivated. I have had consistently good experiences.”

Jun.-Prof. Dr. Hannes Frey
Research Group Computer Networks
+49 5251 60-5380