04947429 is referenced by 81 patents and cites 9 patents.

A method of operating a pay per view television system in which the television signal includes a program tag and an IPPV tag identifying memory locations in subscriber authorization memories. A subscriber can self-authorize his terminal decoder to unscramble a pay per view program with a password that inputs a "1" to the memory location identified by the IPPV tag. The program tag is changed to indicate the memory location identified by the IPPV tag, thus enabling subscribers who bought the program to unscramble the signal. The head-end periodically polls each subscriber terminal to determine the status of the second memory location and to reset it to "0" after the pay per view event.

Title
Pay per view television signaling method
Application Number
126452
Publication Number
4947429
Application Date
November 22, 1989
Publication Date
August 7, 1990
Inventor
Paul M Gosc
Buffalo Grove
IL, US
Richard W Citta
Oak Park
IL, US
Charles B Bestler
Chicago
IL, US
Assignee
Zenith Electronics Corporation
IL, US
IPC
H04L 9/02
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