Abstract:

Technology has a great impact and influence on the educational process in classroom environments. Students can use the advanced computing and telecommunication technologies, to access different types of information and to communicate with their teachers and colleagues using several types of media. Among the new emerging technologies are online three dimensional virtual worlds (3D VWs). This technology can aid students in understanding and predicting physical behaviour, which would otherwise require interactive simulations and laboratories that may be expensive, time consuming and dangerous. Traditional simulations can help carry out virtual experiments but they are often not very interactive, and are frequently complex and slow. 3D VWs provide a natural interactive exploration environment, where individuals and groups can interact and learn. The prototype Wireless Ray-Tracing Educational Land (WRTEL) was built using the OpenSimulator VWs technology, to improve the learning experience for electrical engineering and physics students studying electromagnetic wireless systems. Instead of using textbooks, pictures, equations and paper examples to understand how wireless signals propagate, signals are visualized in an interactive 3D virtual environment.

This paper presents the prototype WRTEL, where invisible wireless signal propagation is made visible using the VW technology. Students are able to visualize signal behaviour (reflection, refraction, diffraction and scattering) in either two dimensions (2D) or three dimensions (3D), and information about each interaction between signals and the surrounding environment can be displayed. The WRTEL consists of three main regions. In the first region, three educational tools have been implemented to explore the relationship between wavelength and frequency, the electromagnetic spectrum and antennas. In the second region, a free space laboratory had been designed in simulated outer space to allow students to visualize line of sight signal propagation between the transmitter and the receiver antennas. In the third region, students are provided with a selectable two or three dimensional ray-tracing laboratory, to create environments using obstacles made from different materials. Students will be able to visualize how signal behaviour (reflection, refraction, diffraction and scattering) is affected by the surrounding environment. Path loss calculations, received power, angle of incidence and many other values will be provided at any point in space until the signal is received by the receiver antenna. The transmitted wireless signals will be visualized by mapping them into the visual spectrum for display; this makes the invisible rays visible.

A brief technical and educational evaluation indicated that the prototype educational land was both usable and would support student learning activities in laboratories.

Keywords:

virtual worlds, wavelength, frequency, electromagnetic spectrum, antennas, Wireless Ray-Tracing Educational Land, OpenSimulator, free space propagation.