900 MHz path loss measurements and prediction techniques for in-building communication system design

The effects of walls, floors, and building type on path loss in four different buildings are considered. Using a simple dⁿ model, average path loss falls off to the n = 3.14 power with a standard deviation of 16.3 dB for the entire data set. However, when the effects of building type and number of floors between the transmitter and receiver are considered, standard deviations are reduced to 5 dB about a mean dⁿ power law. Average floor attenuation factors which describe the additional path loss caused by floors between the transmitter and receiver are found for as many as four floors in a typical office building. Preliminary evaluation of techniques to predict signal strength based on site-specific geometry are presented.