It is sometimes assumed that for a long distance radio link, using a radio operating at 900 MHz is better than at 2.4 GHz. This assumption is based on the fact that, for any given distance, the attenuation suffered by the radio waves (free space loss) increases with the operating frequency. However the free space loss is not the only factor that affects the link performance. This application note points out other factors and compares the operation of the link at the two frequencies.
The first question asked by the novice to microwave networking is always: “How fast does it go?” followed immediately by “What distance does it cover?” The answers are not always simple, because you can gain extra distance by giving up speed, and vice versa. In addition, the performance of the system depends heavily on the choice of antennas. Finally, the local environment (topography, vegetation, weather) will influence your network performance.
This article is an attempt to explain the relationships between these parameters, in order to enable you to properly compare different equipment.