Radio system for reliable data transfer

Abstract

This thesis is a study of a radio system for reliable data transfer in the 433 MHz ISM frequency band. The objective was to express propagation models for two different topologies, and compare these to actual channel behavior by transmitting data in these two scenarios. In addition, different parameters relevance for the radio transmission have been looked at in order to make conclusions about the channel s and the communication system s reliability. By testing on a radio kit, this project has shown that the propagation models found are in varying accordance with the natural behavior of the channel. The open area tests showed that the channel was relatively reliable up to a distance of 40 meters. This result was in accordance to the propagation model. In the forest area the bit error rate was acceptable up to a distance of 30 meters, whereas the propagation model for that area gave a range of 22 meters. An improved loss factor was included to correct this gap. Other parameters, such as the polarization of the antennas, the bit pattern and the block size were also tested to see the influence these had on the performance of the system.