Wired broadcasting systems

Claim 1

A wired broadcasting system which comprises in combination, a plurality of subscribers each having a terminal receiving unit and a terminal subscriber transmission unit connected to a feeder conductor, a plurality of program transmitting equipments each providing a different broadcasting program, a program exchange connected with each subscriber feeder conductor, individual conductors connecting each program transmitting equipment to said program exchange, a program selection device in the program exchange adapted for connecting a subscriber''s feeder to at least some of said individual conductors thereby to be effective to derive program signals therefrom, the subscriber''s feeder conductor comprising a pair of twisted together signal conductors for conveying program signals between the program exchange and the subscriber''s terminal unit, said signal conductors forming between them a pair of interstices in each of which is located a corresponding one of a pair of control conductors for conveying control signals between the subscriber''s terminal unit and the program selection device in the program exchange, coupler meanS in the program exchange coupled between the program selection device and the terminal equipment of each subscriber for transmitting a subscriber transmission to a subscriber feeder conductor irrespective of which program is connected to the subscriber''s feeder conductor, auxiliary switching means in the program exchange enabling a subscriber to establish a signal connection between his coupler means and the transmission unit of a different subscriber and control means coupled by said signal conductors to said auxiliary switching means thereby to establish a selected said signal connection to a subscriber transmission unit.