Radio wave propagation aspects for future digital mobile radio systems

The authors investigate the possibility of using frequencies around 1700 MHz for mobile radio communication, focusing on a comparison of the characteristics of 900 MHz and 1700 MHz radio wave propagation. Radio-wave propagation for mobile radio is broken down into large-scale and small-scale effects. The large-scale variations depend on the BS (base station) to MS (mobile station) distance and also local shadowing by large structures in the terrain such as houses, small hills, and lakes. Parameters which describe such variations are important for system planning of coverage in noise- and interference-limited situations. The small-scale characterization considers how the channel transfer function looks in a very limited area. This data is important in the search for good modulation and demodulation techniques. Such a small area typically represents 5 to 20 meters of traveled distance (15 to 60 wavelengths on 900 MHz and 30 to 120 wavelengths on 1700 MHz)