Since the dawn of civilization, cities have been the communication and information centers of their societies. Various means of communication permit concentration of activities to exchange ideas efficiently, facilitate transactions, and transfer information, which set the boundaries between villages and cities. The larger the city, the more sophisticated are its communication networks. 1
Until the nineteenth century all communications were greatly impeded by distance and limited to direct verbal speech. Communication and travel were synonymous, and communication channels overlay transportation networks in the form of roads, waterways, and later, railroads. Transportation innovations, such as the tramway and automobile, and new communication channels, such as the telephone, began the conquest of the distance barrier and have altered both the speed and location of interaction. Increased mobility permitted expansion of city boundaries, dispersion of residential landscape, and location of industry.
Since the mid- 1970s, new information technologies have increasingly become the means of interactive communication among people scattered throughout the world. Today the tele-