A form of wireless communications that lets users relay information via electromagnetic energy waves from a terminal to a base station which is linked, in turn, to a host computer. The terminal can be placed at a fixed station, mounted on a forklift truck, or carried in a worker’s hand. The base station contains a transmitter and receiver for communication with the terminal. RF systems use either narrow-band or spread-spectrum transmissions. Narrow-band data transmissions move along a single limited radio frequency, while spread-spectrum transmissions move across several different frequencies. When combines with a bar code system of identifying inventory items, a radio frequency system can relay data instantly, thus updating inventory records in so-called real time.