Path loss predictions and measurements over urban and rural terrain at frequencies between 900 MHz and 28 GHz

The authors consider the problem of predicting signal strengths to support rapid deployment of an outdoor wide area network in the aftermath of an attack or a natural disaster. Given that the user has only a digital elevation model (DEM) representation of the area, they ask how map detail, propagation model sophistication, and operating frequency are related to prediction accuracy. They are particularly concerned with signal loss on real paths obstructed by terrain, buildings, and vegetation rather than idealized line-of-sight (LOS) paths. Their assessment is based on a series of 257 signal strength measurements at frequencies of 902 MHz and 2.4, 24.1, and 27.5 GHz made for 63 locations on the Virginia Tech campus.