Channel assignment for CATV system

• US 4,527,194 A
• Filed: 07/27/1983
• Issued: 07/02/1985
• Est. Priority Date: 07/27/1983
• Status: Expired due to Fees

• Current Assignee: Zenith Electronics Corporation (LG Corporation)
• Original Assignee: Zenith Electronics Corporation (LG Corporation)
• Inventors: Sirazi, Semir
• Primary Examiner(s): George, Keith E.
• Application Number:
  US06/517,876
• Time in Patent Office: 706 Days
• Field of Search: 358/86, 358/191.1, 358/192.1, 358/195.1, 455/3, 455/4, 455/6, 455/186
• US Class Current: 725/151
• CPC Class Codes: H03J 5/0281 the digital values being held in an auxiliary non erasable memory
• CPC Class Codes: H04N 21/4383 Accessing a communication channel
• CPC Class Codes: H04N 7/162 Authorising the user terminal, e.g. by paying; Registering the use of a subscription channel, e.g. billing

Abstract

A CATV channel assignment system and method for arranging CATV channels in a tiered fashion facilitates selective viewer access to predetermined groups of CATV channels. A "logical" channel number is generated upon channel selection and is provided to a microcomputer which, in turn, generates a corresponding lock-up PROM address. The logical channel number is converted by means of the thus generated address to a "physical" channel number in the PROM. The physical channel number represents a standard CATV channel and is provided to the microcomputer for synthesizing the correct tuning frequency via a phase lock loop and conventional tuning circuitry. For a two cable system automatic cable switching is provided to permit channels on either cable to be included within the same group of selected channels. The present invention facilitates the "tiering" of CATV channels into predetermined groups of channels, wherein each group has a viewer access authorization level associated therewith, and in which all channels in a group may be assigned logically related channel numbers, e.g., consecutively arranged channel numbers, while the corresponding standard channel numbers may be widely disparate and unrelated in a given group. This arrangement facilitates viewer channel selection by organizing subscribed-to channels into easily remembered numerical sequences and simplifies selective accessing of CATV channels by arranging these channels into two or more tiers where the channel numbers in each tier are logically related and not randomly assigned.

Claims

1. A CATV tuning system for tuning to a plurality of CATV channels transmitted on at least one cable from a CATV head end with each of said CATV channels having a corresponding physical channel number related to an assigned carrier frequency of said CATV channel, said system comprising:

channel selector means responsive to user initiated inputs for generating a logical channel number representing a selected CATV channel;

memory means having a plurality of addressable storage locations in each of which is stored a physical channel number having an associated carrier frequency;

signal processing means coupled to said channel selector means and to said memory means and responsive to a logical channel number generated by said channel selector means for converting said logical channel number to a lock-up address in said memory means, the contents of the memory storage location defined by said look-up address representing a predetermined physical channel number, for reading the contents of said given look-up address therefrom, and for converting the contents of said look-up address to a tuning frequency word associated with said physical channel number; and

tuning circuitry coupled to said signal processing means and responsive to said tuning frequency word for tuning to the carrier frequency of said physical channel number.

2. A system as in claim 1 wherein said CATV channels are received on a plurality of cables with said system including automatic cable switching means coupled to said signal processing means and to said cables for automatically switching to the cable on which the selected CATV channel is provided in response to the entry of a logical channel number.

3. A system as in claim 1 further including mode switch means coupled to said signal processing means for switching said system to a first mode wherein said physical channel numbers are entered in said channel selector means or for switching said system to a second mode wherein said logical channel numbers are entered in said channel selector means in tuning to a desired CATV channel.

4. A system as in claim 1 further including channel number display means coupled to said signal processing means for displaying a selected channel number.

5. A system as in claim 1 wherein said CATV channels are received on a plurality of cables with said system further including manual switch means coupled to said signal processing means and responsive to user initiated input commands for switching said system to the cable on which a desired CATV channel is received.

6. A system as in claim 1 wherein said signal processing means includes a microcomputer and said memory means includes a programmable read only memory.

7. A system as in claim 1 further including means coupled to said signal processing means for energizing said memory means prior to the reading of the contents of a look-up address in said memory means by said signal processing means.

8. A system as in claim 1 wherein said look-up address representing a given physical channel number is provided to said signal processing means in the form of a multi-bit digital word and wherein one of said bits designates the cable on which a CATV channel corresponding to said physical channel number is received.

9. In a CATV tuning system wherein CATV channels are transmitted from a CATV head end on at least one cable with each CATV channel having associated therewith a physical channel number corresponding to an assigned carrier frequency, a method for tuning said CATV channels comprising:

assigning a logical channel number to each of the transmitted CATV channels;

storing each of said physical channel numbers in a respective addressable location of a memory device;

selecting a logical channel number representing a desired transmitted CATV channel for tuning;

converting the selected logical channel number to a given address of said memory device;

reading the physical channel number stored in the memory location of said memory device defined by said given address; and

generating a tuning frequency corresponding to the physical channel number read from said memory device in tuning to the carrier frequency of the selected CATV channel.

10. A method as in claim 9 further comprising the step of automatically switching to the cable on which the selected CATV channel is received upon the selection of a logical channel number where said CATV channels are received on a plurality of cables.

11. A method as in claim 9 further comprising the step of displaying a selected logical channel number.