×

Conditional access system of CATV

  • US 6,868,550 B1
  • Filed: 04/10/2000
  • Issued: 03/15/2005
  • Est. Priority Date: 04/09/1999
  • Status: Expired due to Fees
First Claim
Patent Images

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.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×