CATV Service controller

• US 4,461,032 A
• Filed: 06/21/1982
• Issued: 07/17/1984
• Est. Priority Date: 06/21/1982
• Status: Expired due to Fees

• Current Assignee: Zenith Radio Corporation
• Original Assignee: Zenith Radio Corporation
• Inventors: Skerlos, Peter C.
• Primary Examiner(s): Bookbinder, Marc E.
• Application Number:
  US06/390,092
• Time in Patent Office: 757 Days
• Field of Search: 455/1, 455/3, 455/4, 455/26, 358/114, 358/122, 358/86, 358/117, 340/825.07
• US Class Current: 725/25
• CPC Class Codes: H04N 7/165 Centralised control of user terminal subsequent to an upstream request signal H04N7/17345; Registering at central by two-way working H04N7/17309

Abstract

A remotely located and controlled programming controller for a cable-compatible television receiver is disclosed. Cable head end-generated control signals are provided by wire to the cable TV controller for selectively enabling the reception of subscribed-to CATV channels by the television receiver. Coded subscriber addressing and operating mode control signals are provided to each controller in the cable network for selectively enabling/disabling each controller for limiting cable programming distribution. Each controller is responsive to transmitted operating mode control data bits for enabling/disabling individual cable channel reception. In addition, each controller is assigned and responsive to subsequently transmitted, uniquely coded address identifier data bits. Operating mode control and address data are represented respectively by the first and last bit groups of the head end-generated cable access signal. The programming controller may be remotely located in coupling the television receiver to the cable network with system status monitoring provided by head end-generated probe signals for enhanced programming security.

Claims

1. In a remotely controlled cable television distribution system having a cable and a head end wherein are generated addressing and operating mode control signals for providing for the selective transmission of programming signals to a plurality of subscribers in said cable distribution system, wherein said addressing signals provide for the selective accessing of individual subscriber television receivers by said head end and said operating mode control signals provide for the selective distribution of said programming signals representing a plurality of cable television channels to said plurality of subscribers, a cable television service controller remotely located from a respective subscriber television receiver to which it is coupled, said service controller comprising:

programmable memory means for storing an address code representing an individual subscriber coupled to said cable television distribution system;

comparator means coupled to said cable and said programmable memory means for comparing an addressing signal from said cable head end and said stored address code for generating an actuation signal when said addressing signal and said stored address code correspond; and

control means coupled to said cable and said comparator means and responsive to said actuation signal for selectively providing said programming signals representing said plurality of cable television channels to the subscriber coupled thereto in accordance with said operating mode control signals following receipt of an addressing signal representing said subscriber, said control means including a plurality of RF electronic switch and signal filter combinations, wherein each of said signal filters includes a plurality of passive components in combination, with each component combination tuned to a predetermined frequency corresponding to the frequency of a respective cable television channel, with the respective electronic switch coupled thereto connected to neutral ground potential for selectively grounding a programming signal provided thereto.

2. A cable television controller as in claim 1 wherein each of said signal filters includes a passive bridged-T filter.

3. A cable television service controller as in claim 1 wherein said programmable memory means includes a read only memory and said comparator means includes a microprocessor for comparing said stored address code with said address signal and generating said actuation signal in response to said comparison.

4. A cable television service controller as in claim 1 wherein said controller is energized by a low level DC voltage provided by said cable head end.

5. A cable television service controller as in claim 1 wherein said address and operating mode control signals are modulated on an RF carrier frequency located between adjacent cable programming singal frequencies.

6. A cable television service controller as in claim 1 wherein said control means includes a plurality of electronic switch and two-terminal notch filter combinations each coupled in parallel to said cable, with each notch filter exhibiting a sharp frequency rejection characteristic of a desired, relatively high attenuation level at the frequency of one of said programming signals whereby an electronic switch is rendered conductive in response to receipt of an actuation signal for rendering a respective notch filter conductive and grounding a respective programming signal.

7. In a remotely controlled cable television distribution system having a cable and a head end wherein are generated addressing and operating mode control signals for providing for the selective transmission of programming signals to a plurality of subscribers in said cable distribution system, wherein said addressing signals provide for the selective accessing of individual subscriber television receivers by said head end and said operating mode control signals provide for the selective distribution of said programming signals representing a plurality of cable television channels to said plurality of subscribers, a cable television service controller remotely located from a respective subscriber television receiver to which it is coupled, said service controller comprising:

programming memory means for storing an address code repesenting an individual subscriber coupled to said cable television distribution system;

comparator means coupled to said cable and said programmable memory means for comparing an addressing signal from said cable head end and said stored address code for generating an actuation signal when said addressing signal and said store address code correspond; and

control means coupled to said cable and said comparator means and responsive to said actuation signal for selectively providing said programming signals representing said plurality of cable television channels to the subscriber coupled thereto in accordance with said operating mode control signals following receipt of an addressing signal representing said subscriber;

wherein said service controller is responsive to a probe signal provided thereto by said cable head end for monitoring the status of said service controller and for providing the cable head end with a status signal representing the operating mode of said service controller.

8. A method of selectively distributing a plurality of cable television channel frequencies to a plurality of service controllers coupled to a cable distribution network, said method comprising the steps of:

transmitting a first group of data bits representing selective ones of said plurality of cable television channel frequencies on said cable distribution network from a head end thereof;

transmitting a second group of data bits representing an individual service controller on said cable distribution network from said head end;

comparing said second group of data bits with an address code uniquely representing said individual service controller;

filtering out selective ones of said plurality of cable television channel frequencies in accordance with said first group of data bits if said second group of data bits and said address code do not correspond or leaving the distribution of said cable television channel frequencies unchanged if said second group of data bits and said address code correspond; and

transmitting a probe signal from said head end to said service controllers for monitoring the status of each of said service controllers and for providing the cable head end with a status signal representing the operating mode of each of said service controllers.