| 摘要 |
<p>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 look-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.</p> |
