Baltimore´s fort McHenry tunnel cellular booster

A cellular booster (or cellular reradiation) system is now providing cellular radio service inside Baltimore´s new Fort McHenry tunnel. Since its recent installation the performance of this system has been monitored and recorded on numerous occasions. In addition, various system components have been fined tuned, altered and changed to further improve the system´s technical performance. A cellular booster consists of a broadband class A RF amplifier preceded by two 10 MHZ wide filters. The single amplifier is used to retransmit mobile signals to the cell site and cell site signals to mobiles. A directional antenna is aimed at the serving cell and another antenna system is aimed at the coverage problem area. The intent of this paper is to share the experiences of a cellular service provider who has utilized this new technology in a tunnel environment and concluded that cellular boosters can provide cellular tunnel coverage in a cost effective manner.