Abstract: An optical communication system is disclosed wherein a multiplicity of stations in a linear, random, or grid arrangement are coupled in a party-line type network in which optical signals originated by a master or responding station are relayed from station to station. Coupling between stations may be accomplished by means of optical lenses, the focal regions of which are coupled to electronic equipments that may be remotely located therefrom. This electronic equipment detects received optical signals, regenerates and retransmits these received optical signals, and originates a responding optical signal to the master station when the received optical signal is addressed to the receiving station.

Abstract: An object identification system using an RF roll-call technique wherein an interrogator illuminates a multitude of cooperating objects with a sequence of codes and receives from each such cooperating object an acknowledge signal immediately following the transmission of the code associated with that object and which terminates prior to completion of transmission of the next code in the sequence.

Abstract: A data transmission system utilizing the telephone voice communication network for transmitting data between the location of a telephone subscriber's handset and a central station. A data transmitter is capacitively coupled to a bridge tap on the subscriber loop at the subscriber's handset and a data receiver is capacitively coupled to a bridge tap on the subscriber loop at the associated telephone company central office. The data transmissions occur at frequencies outside the standard telephone voice transmission frequency band of the system thereby providing continuous data transmission service without interfering with the normal voice communication function of the system.