Penetration Loss of Doors and Windows inside Residences using ISDB-T Digital Terrestrial Television Signal at 677 MHz

This paper presents the results of indoor propagation measurements conducted at 16 residential sites at 677 MHz using live digital television transmission of National Broadcasting Network (NBN). This study is part of the extensive measurement campaign done last March to May 2011, in partnership with NBN, a government TV network. The main purpose of this study is to validate the digital TV performance of the Japanese TV standard, Integrated Services Digital Broadcast-Terrestrial (ISDB-T). Sixteen residences located in an urban area within 7 kilometers of NBN were chosen falling under Classes A, B, C and D categories of houses in the Philippines. Using a commercially available indoor antenna placed on top of a tripod at a height of 1.5 meters, power received in dBm is measured using a spectrum analyzer. Data is captured in a storage device and reception is visually monitored using a set top box and a TV set. Measurement points are large openings of the house like doors and windows and data is captured every cluster measurements of 9 points on each spot. An antenna is placed directly in front of the doors and windows to establish RF reference level outdoor. Indoor signal strength is measured and compared with the outdoor reference level. The drop in signal level establishes the effects of materials to the transmitted signal and thereby helps identify the reason for signal degradation. The difference between outdoor and indoor signal levels also helps evaluate the penetration loss of different materials like wooden doors, glass windows, jalousie windows, window frames, concrete walls, GI sheets and metals. These are typical residential local materials. Average Penetration Loss (APL) for each house/building category using the difference between the measured outdoor signal level and the indoor signal level values were computed and compared with similar studies found in the literature.