Conditional access system of CATV
First Claim
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1. A CATV conditional access system comprising:
- a plurality of analog head ends for distributing picture signals of analog programs and picture signals of transmitted digital programs to terminals provided in respective areas; and
a digital head end for transmitting the picture signals of the digital programs to the plurality of analog head ends, wherein said digital head end transmits to the terminals within the areas, via the analog head ends, data containing an area code used to recognize the area to which each terminal belongs, and data containing a channel contrastive table for comparing a management number that is uniquely allocated to each analog program and is commonly used in all the areas for each respective analog program and a channel display number used in each area for selecting an analog program, and each of said terminals stores thereinto the area code and the channel contrastive table, and retrieves the corresponding management numbers from the channel contrastive table by comparing the channel display numbers for selecting the analog programs set for each area and the area code, and then displays the channel display number for selecting the analog program of the retrieved management number.
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Abstract
In a CATV system, a digital head end transmits both an area code and such data containing a management number and a channel contrastive table to a terminal of each of areas; each terminal stores thereinto both the area code and the channel contrastive table; and the digital head end retrieves the corresponding management number by comparing a channel display number of an analog program set every area with the channel contrastive table based on this area code, and then, displays the analog program of this retrieved management number.
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Citations
9 Claims
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1. A CATV conditional access system comprising:
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a plurality of analog head ends for distributing picture signals of analog programs and picture signals of transmitted digital programs to terminals provided in respective areas; and
a digital head end for transmitting the picture signals of the digital programs to the plurality of analog head ends, wherein said digital head end transmits to the terminals within the areas, via the analog head ends, data containing an area code used to recognize the area to which each terminal belongs, and data containing a channel contrastive table for comparing a management number that is uniquely allocated to each analog program and is commonly used in all the areas for each respective analog program and a channel display number used in each area for selecting an analog program, and each of said terminals stores thereinto the area code and the channel contrastive table, and retrieves the corresponding management numbers from the channel contrastive table by comparing the channel display numbers for selecting the analog programs set for each area and the area code, and then displays the channel display number for selecting the analog program of the retrieved management number. - View Dependent Claims (2, 3, 4, 6, 7, 8)
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5. A CATV conditional access method comprising the steps of:
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providing a plurality of analog head ends for distributing picture signals of analog programs and picture signals of transmitted digital programs to terminals provided in respective areas;
providing a digital head end for transmitting the picture signals of digital programs to the plurality of analog head ends;
transmitting to the terminals within the areas, via the analog head ends, data containing an area code used to recognize the area to which the area belongs, and data containing a channel contrastive table for comparing a management number that is uniquely allocated to each analog program and is commonly used in all the areas for each respective analog program, and a channel display number used in each area for selecting an analog program;
storing in each of said terminals the area code and the channel contrastive table;
retrieving the corresponding management numbers from the channel contrastive table by comparing the channel display numbers for selecting the analog programs set for each area and the area code; and
displaying the channel display number for selecting the analog program of the retrieved management number.
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9. A CATV conditional access system comprising:
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a digital head end for transmitting picture signals of digital programs to a plurality of analog head ends, the plurality of analog head ends for distributing picture signals of analog programs and the picture signals of the transmitted digital programs to terminals provided in respective areas, wherein said digital head end transmits to the terminals, via the analog head ends, data containing an area code used to recognize the area to which each terminal belongs, and data containing a channel contrastive table, wherein the channel contrastive table compares a management number with a channel display number, the management number being uniquely allocated to each analog program and commonly used in all the areas for each respective analog program, and the channel display number used in each area for selecting an analog program.
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Specification