Interconnection technology

Two areas of the electromagnetic spectrum are potential candidates for supporting high capacity radio communication systems, namely the infra-red (IR) band, and the ultra high frequency (UHF) band. The IR band is extensively used in the home for remotely controlled devices. In such applications the data rate is low, and a direct line of sight between the transmitter and the receiver is not difficult to achieve. IR communications will operate if no direct line of sight is available, but a reflected path is. As IR communications are close to visible light in frequency, and warm bodies emit IR radiation, communication links are subject to large amounts of noise from the environment. Obviously such a medium is not conducive to the development of a dynamic network that must support a high bandwidth of communication as envisaged for office communications.

UHF communication links differ from IR links in a number of respects. Many of the surfaces in an office environment will appear as opaque objects for IR communications, but as transmissive objects for UHF communications. This has an advantage in that groups of offices in a building requiring separate IR transceivers for each office can be served by one cell site operating in the UHF band.