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TWO-WAY COMMUNITY ANTENNA TELEVISION SYSTEM

  • US 3,668,307 A
  • Filed: 03/30/1970
  • Issued: 06/06/1972
  • Est. Priority Date: 03/30/1970
  • Status: Expired due to Term
First Claim
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1. A two-way closed circuit television system comprising a plurality of remote terminal stations connected to a central transmitting station by means of a transmission line capable of carrying simultaneously a plurality of communication channels including television channels, said system comprising:

  • a. means coupled to said transmission line for limiting some of said channelS, designated as forward channels, to signal transmission in the opposite or return direction, b. a control station connected via said transmission line to said central station and to said plurality of terminal stations for controlling access of said remote terminal stations to said communication channels and comprising a computer for continually and serially transmitting to said remote terminal stations via a forward control channel of said transmission line a list of digital code groups, each code group comprising an instruction word and a terminal address word, c. each terminal station comprising;

    1. a digital control unit having a plurality of inputs and outputs and comprising;

    a. address storage means for storing the unique address of that terminal station, 2. comparator means coupled to said address storage means for sequentially comparing each of said transmitted terminal address words with the stored unique address, 3. decoder means coupled to said comparator means and responsive to a match between said unique address and a terminal address word for decoding the instruction word in the code group containing the matched address word, and 4. control circuits responsive to the decoded instruction word for controlling access of said terminal station to said plurality of communication channels, d. a television receiver at each said terminal station and adapted to be electrically connected by operation of said digital control unit to selected communication channels of said transmission line, and e. said central transmitting station having means for transmitting on the forward television channels television programs on unique television channel carriers for reception by each television receiver whose terminal station has been granted access to a corresponding unique forward television channel by said control circuits.

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