Video selection and distribution system
Method and apparatus for tuning data channels in a subscription television system having in-band data transmissions Patent #: 5247364
ApplicationNo. 090502 filed on 07/13/1993
US Classes:725/116, Control process348/555, For receiving more than one format at will (e.g., NTSC/PAL)725/104, Pay-per-view725/114, Server or headend725/131Receiver (e.g., set-top box)
ExaminersPrimary: Harvey, David E.
Attorney, Agent or Firm
Foreign Patent References
International ClassesH04N 005/46
AbstractA cable television system has a multiplicity of television program sources providing television signals in various predefined television signal formats. The program sources include continuous television sources provided to all users free of charge as well as pay-per-view program sources transmitted to users only upon request. Each television has a multi-standard receiver for receiving television signals in those predefined television signal formats, and is coupled to a transmission medium such as a coaxial cable. A television signal switch transmits the television signals from various ones of the program sources onto the transmission media in assigned respective frequency channels. Hidden behind each television, or elsewhere out of view of the user, is a converter coupling the respective television to the transmission media. The only connection from the converter to the television is a cable connected to the television's cable or antennae input port. Each converter includes a controller for selecting a channel in accordance with user commands, a channel map memory for storing data assigning to each accessible channel a frequency band and a predefined television signal formats, and a frequency converter for switching a television signal received from transmission media on the selected channel to a predefined output channel to which the television is tuned. Each respective controller also includes an upstream transmitter for transmitting user program selection commands onto the transmission medium. The user program selection commands are received by a controller that decodes those commands and transmits corresponding setup signals to the television signal switch.