21 April 2006 An aerial view Integrated antennas enable the virtual office on trains. By Robin George. With wireless services about to become broadly available, train passengers will expect to use their PDAs, notebooks and other devices to make calls from the train and have access to internet, email and infotainment applications. Demand from busy executives for a ‘virtual office’ is encouraging train operators to provide this access as a useful value added service or as a potential revenue stream. Being an almost perfect Faraday cage, railway carriages will attenuate or block radio signals from the outside world and vice versa. So there is little chance for any mobile communications operator to provide a high quality service inside a train without the use of radio repeaters. This is especially true for modern trains using metallic windows for climate control. The configuration shown in figure 1 comprises a set of three repeaters: GSM 900, GSM1800 and UMTS. The repeaters and the combiner network are hosted within special equipment rooms inside the carriages. The antenna connects to the output of the repeater combiner network – in this case, a triplexer that handles GSM900, GSM1800 and UMTS. Radio signals are picked up outside the carriage by the antenna, reamplified within the repeaters and transmitted either to a leaky feeder or to directional antennas which provide seamless coverage inside the carriage. Author Graham Pitcher Comment on this article Websites http://www.hubersuhner.co.uk Companies Huber & Suhner (UK) Ltd This material is protected by MA Business copyright See Terms and Conditions. One-off usage is permitted but bulk copying is not. For multiple copies contact the sales team. What you think about this article: Add your comments Name Email Comments Your comments/feedback may be edited prior to publishing. Not all entries will be published. Please view our Terms and Conditions before leaving a comment.