Attenuation of radio wave signals coupled into twelve large building structures

Certain commercial entities, equipment, or materials may be identified in this document in order to describe an experimental procedure or concept adequately. Such identification does not imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that the entities, materials, or equipment are necessarily the best available for the purpose. Executive Summary This is the fourth in a series of NIST Technical Notes (TN) on propagation and detection of radio signals in large building structures (apartment complex, hotel, office building, sports stadium, shopping mall, etc.). The first, second, and third NIST Tech Notes (TN 1540, TN 1541, and TN 1542) described experiments for radio propagation in a structure before, during, and after implosion. The data in these reports give first responders and system designers a better understanding of what to expect from the radio-propagation environment in disaster situations. The goal of this work is to create a large, public-domain data set describing the attenuation of radio signals in various building types in the public safety and cellular telephone bands. With the above goal in mind, measurements were carried out on 12 different large building structures. Frequencies near public safety and cell phone bands as well as ISM and wireless LAN and 4.9 GHz) were chosen for these experiments. We carried out these " radio-mapping " experiments to provide data on how radio signals at the different frequencies coupled into the different building structures. Radio transmitters similar to those used by first responders were used, as well as specially designed transmitters for the higher frequencies. These different transmitters were carried throughout various large building structures, while the received signal was recorded at a fixed receive site located outside the large structures. From this we determined the field-strength variability throughout the structures. Transmitters were also carried around the perimeter of the structures with a fixed receiving site on the outside. The results of these signal-strength measurements and the statistical analysis of the data for these radio-mapping experiments are presented here. Beside plots of the raw datasets, a series of tables that summarize the processed data by frequency bands are presented in this report. This enables easier comparisons between results from different building or structure types. (Note that the exact frequencies are provided in each of the individual site discussions.) Table entries include a building or structure identifier, the actual frequency tested, the specific reference level used …