Microwave Opportunities for City Communication and for Motor-Car Traffic Handling

Abstract

Modern cities arc based on high density of office space in the centre with the corresponding features of high rising buildings and more peripherally the residential areas with a reduced density of housing space. Important facilities for such a system are then an efficient and easy to use communication technique and an effective motor-car-traffic handling which ensures full use of the available road space. The narrow-band signal transmission for such services as telephony and e-mail are covering the frequency bands around 2 GHz, also with the almost completed satellite-based mobile communication system Iridium. At higher frequencies, the building structures cause stronger multiple reflections so that here the transmission characteristics is more suited for more localized operation. Going to very high frequencies, the absorption in air becomes particularly strong so that advantageous are indeed those application where strictly local operation is needed. On the other hand, high frequencies give advantages of a bandwidth which is particularly important for video-type communication as forseen with multimedia applications.