Penetration of Radio Signals Into Buildings in the Cellular Radio Environment

Penetration of radio signals from Advanced Mobile Phone Service cell site transmitters has been measured in fourteen office and industrial buildings in the Chicago area. Signal levels on the first floor of buildings averaged 14 dB less than reference levels in the adjacent streets. This penetration loss was found to decrease with increasing height. Standard deviations of penetration loss ranging from 5 to 11 dB attest to the diversity of architecture and floor arrangements. Other relationships useful in planning for portable phone terminal applications are derived from the data and are presented in this paper. The data include over 4000 measurements, each being the average of 1024 samples of the local field taken over an eight-second period as the instrumentation traveled about 20 feet over the measurement path. The measurement path in each building was traversed for each of the several cell sites that transmitted signals of adequate strength into the buildings.