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System and method for providing compressed digital teletext services and teletext support services

  • US 5,519,780 A
  • Filed: 12/03/1993
  • Issued: 05/21/1996
  • Est. Priority Date: 12/03/1993
  • Status: Expired due to Term
First Claim
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1. In a receiver of a communication system for receiving digital data streams of a plurality of services multiplexed in a sequence of frames, wherein a frame of said sequence of frames includes a teletext header packet defining at least a portion of a teletext page and having a plurality of filter fields, each filter field having a filter value, an apparatus for generating a teletext page comprising:

  • extracting means for extracting the teletext header packet from the frame, wherein said teletext header packet includes a page number filter field having a page number value and a plurality of aggregate filter fields each having a filter value;

    comparing means for comparing the filter value for each filter field of the extracted teletext header packet to a corresponding requested filter value and for generating a matching signal if each filter value matches the corresponding requested filter value, wherein said comparing means comprises;

    a page comparator for comparing the page number value to a requested page number value; and

    an aggregate filter comparator for comparing the filter values of the aggregate filter fields to corresponding requested filter values, wherein the aggregate filter field comprises a language filter field having a language value, and wherein said aggregate filter comparator comprises a filter comparator for comparing the language value to a requested language value; and

    constructing means, responsive to the matching signal, for constructing the portion of the teletext page defined by the extracted teletext header packet.

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