Microwave propagation and communication networks

Recent evolution of telecommunication networks has been strongly influenced by two main trends: an increase of radio (microwave radio links, satellite links, and mobile services) with respect to cable communication, and a rapidly progressing development of digital transmission techniques compared with analogic techniques. The first tendency leads to saturation of the frequency bands presently used for radioelectric systems and hence the need of going to higher as well as yet unused bands. Digital systems on the other hand are particularly prone to interruptions even of very short duration and such cuts can only be tolerated for extremely low time percentages. The object of this communication is to study the role of propagation conditions in the future solution of these problems, imposing a limit on the distance between repeaters or using diversity techniques.