A general description of both cellular and satellite communication systems for mobile terrestrial communications is given. The current state of development and use of these systems is given, together with predictions for expansion of the networks into new markets, such as an extension of the public telephone service to aircraft. Particular emphasis is placed on the role of new microwave technology, both in regard to the future for GaAs monolithic circuits and to prospects for the use of higher frequencies in the mm-wave band. Examples of systems and technology from both civil and military applications are used to illustrate the importance of mobile communications in the exploitation of advanced technology.