Addressable cable television control system with video format data transmission

• US 4,536,791 A
• Filed: 06/04/1984
• Issued: 08/20/1985
• Est. Priority Date: 03/31/1980
• Status: Expired due to Term

• Current Assignee: General Instrument Corporation (CommScope Holding Company, Inc.)
• Original Assignee: Tocom, Inc. (CommScope Holding Company, Inc.)
• Inventors: Campbell, John G., Schoeneberger, Carl F., Bundens, Allan B., Lemburg, John R., Fogle, Richard M.
• Primary Examiner(s): BUCZINSKI, STEPHEN C
• Application Number:
  US06/617,137
• Time in Patent Office: 442 Days
• Field of Search: 358/114, 358/147, 358/263, 358/259, 358/122
• US Class Current: 725/28
• CPC Class Codes: H04N 7/03 Subscription systems therefor
• CPC Class Codes: H04N 7/0888 Subscription systems therefor
• CPC Class Codes: H04N 7/162 Authorising the user terminal, e.g. by paying; Registering the use of a subscription channel, e.g. billing
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58
• CPC Class Codes: H04N 7/17363 at or near the user terminal

Abstract

An addressable cable television control system controls television program and data signal transmission from a central station to a plurality of user stations. The data signals include both control and text signals in video line format which are inserted on the vertical interval of the television signals, thereby freeing all channels for transmission of both television and data signals. Moreover, full-channel teletext data in video line format may be transmitted on dedicated text channels with the modification of only head end processors. An intelligent converter at each remote user location uses the data signals to control access to the system on the basis of channel, tier of service, special event and program subject matter. The converter uses a graphics display generator to generate display signals for the presentation of the text data on the television receiver and for the generation of predetermined messages for the viewer concerning access, emergencies and other functions. The converter processes vertical interval text data and selected full-channel text data, both transmitted in video line format. The keyboard of the subscriber provides a number of different functional inputs for the subscriber to interface with the system. The converter also includes apparatus for interfacing with two-way interactive data acquisition and control systems.

Claims

1. In a television communications system having a central station for transmitting a plurality of television signals at different frequency channels to a plurality of user stations remote from said central stations, each having a tuner for selecting one of said television signals, a method of utilizing said central station to limit access of said user stations to only certain ones of said television signals, comprising:

generating a plurality of category codes at said central station to limit user access to predetermined categories of said television signals, one of said category codes being generated for each user station, each said category code including predetermined enabling data required by the central station for said user station to access said predetermined categories of television signals;

transmitting each of said category codes from the central station to its respective user station to precondition each user station by authorization from the central station to selectively access said predetermined categories of television signals;

generating a plurality of program codes at said central station to limit user access to said predetermined categories of television signals, one of said program codes being generated for each television signal, each of said program codes including predetermined control data for enabling access to one of said television signals;

transmitting one of said program codes with each of said television signals to each of said user stations being tuned to receive one of said television signals;

comparing the control data of said program code to the enabling data of the category code provided by the central station to each user station; and

enabling only each user station which has a category code with enabling data corresponding to the control data of said program code, whereby said enabled user station can receive and process any said tuned television signal within a predetermined category of said television signals corresponding to said category code.

2. The method of claim 1 wherein the access criterion corresponds to a predetermined frequency channel.

3. The method of claim 1 wherein the access criterion corresponds to a predetermined tier of service regardless of frequency channel.

4. The method of claim 1 wherein the access criterion corresponds to a given program on a given frequency channel.

5. The method of claim 1 wherein the access criterion corresponds to the type of subject matter of a given program on a given frequency channel.

6. The method of claim 1 and further comprising the steps of generating a graphics display signal for those user stations having user codes not corresponding to said program code.

7. The method of claim 6 and further comprising the step of presenting a message on said television set in response to said graphics display signal to indicate that access to said one television signal is not enabled for said user station.

8. The method of utilizing a central station to limit remote user access to a plurality of cable television signals each transmitted at a different frequency channel on a cable plant from said central station to a plurality of user stations remote from said central station, each having a tuner for selecting one of said television signals, comprising:

generating a plurality of category codes at said central station to limit user access to predetermined categories of said television signals, each category code being representative of the access criteria required for one of said user stations to receive said predetermined categories of television signals, each said category code including a channel enable code representative of the frequency channels of said television signals to which said user station is authorized for access, a tier enable code representative of a user level at which said user station is authorized for access to said television signals, and a program enable code representative of a predetermined time at which said user station is authorized for access to one of said television signals;

transmitting each of said category codes from the central station to its respective user station;

storing each of said category codes at said respective user station;

generating a plurality of control codes at said central station to limit user access to said predetermined categories of television signals, each control code being representative of the access criteria required for said user stations to receive one of said television signals, said control code having a tier code representative of a user level required for access to said one television signal and a program code representative of user access to a given program transmitted by said television signal at a predetermined time;

transmitting said control code to each user station tuned to said television signal;

comparing said control code of the tuned television signal to the category code of said user station provided by the control station, including comparing the channel enable code to the channel frequency of said tuned television signal, comparing the tier enable code to the tier code of the tuned television signal, and comparing the program enable code to the program code of said television signal; and

enabling said user station to access to said tuned television station in response to the channel enable code corresponding to the tuned channel, of the tier enable code corresponding to the tier code, or the program enable code corresponding to the program code.