Decoupled Active/Passive Base Stations for Second Generation Cellular Networks

The effect of electromagnetic radiations from wireless cellular telephony systems on human health has been intensely discussed. As a result, and despite the lack of evidence on any adverse effects, recent regulations make network planning even more difficult. Base stations, even those covering urban areas, tend to be placed at suburban locations (in this paper we cite some examples of related local regulations). In these cases, mobile stations inside urban locations must raise their power transmission level to reach suburban antenna placements. Therefore, users may complain of a higher radio exposure. In this work we propose a feasible solution to reduce electromagnetic activity from mobile communications equipment and to cope with restrictive placement regulations. To accomplish this goal, a suburban base station is divided into an active part (transmitter) that is kept at the suburban location, and a passive part (receiver), which is moved inside the urban area. Thereby, the power received from the base station can be considered negligible inside the urban area (since the active part is far away), and mobile terminal/stations transmit lower power levels (since passive receivers are close to them). We justify the solution in the context of the globally available GSM networks, both analytically and with empirical and simulation tests. The results in this paper reveal that our approach reduces electromagnetic levels and improves uplink quality, which reaches typical levels of urban base stations.