Abstract: A communication system for use in an area having a human environment delimited from below by a floor and from above by an overhead environment substantially clear of human presence. The communication system includes a first information source operative to independently generate first information; a plurality of second information sources, each operative to independently generate second information; a plurality of controllers, each coupled to the first information source and arranged in the overhead environment, for producing a substantially downwardly directed communication beam at a prescribed carrier frequency, imparting the first information to the beam, receiving a reradiated version of the beam and detecting therefrom the second information, the controllers being arranged such that the beams substantially contiguously irradiate a region of said human environment; and a plurality of communicators, each coupled to one of the second information sources and arranged in the human environment.