This page is best viewed with Microsoft Explorer. Netscape doesn't do greek or special characters. For ground mobile systems, median path loss between a transmitter and a receiver is usually, but not always, much higher than predicted by free space propagation laws. Fall-off rates revert to R 2 and slower at short ranges.
Variability is high.
This will have profound implications for microcellular deployments since classic engineered frequency reuse patterns and techniques are not viable. Field measurements have shown that large scale shadow fading due to buildings, terrain variations etc. tends to be log-normally distributed about the median signal strength. As a consequence, shadow fading tends to change slowly, especially for slow moving users as is shown in Figure 1a. Because of phase shifts, replicas may either tend to reinforce or cancel each other. Amplitude statistics of narrowband signals in multipath fading are often characterized as Ricean with the degenerate case of Raleigh fading in diffuse reflection environments.