EN 62297-2:2005

INTRODUCTION
1 Scope
2 Normative references
3 Terms, definitions and abbreviations
  3.1 Definitions
  3.2 Abbreviations
4 Teletext-based methods
  4.1 Page-format method
      4.1.1 Maximum length of a trigger message
      4.1.2 Data stream
      4.1.3 Transmission aspects
  4.2 Independent data line method
      4.2.1 Maximum length of a trigger message
      4.2.2 Data stream
      4.2.3 Packet structure
5 MPEG-2 transmission based method
Annex A (informative) Code of practice
      A.1 Page-format teletext transmissions
          A.1.1 General
          A.1.2 Page number
          A.1.3 Magazine Inventory Page
          A.1.4 20ms page delay
      A.2 Independent data line teletext transmissions
          A.2.1 General
          A.2.2 Alternative protocol stacks
          A.2.3 Fast trigger applications
Annex ZA (normative) Normative references to international
         publications with their corresponding European
         publications

specifies how the trigger messages defined in EN 62297-1 are transmitted. A trigger is defined as information sent from a service provider as part of a data broadcasting transmission that initiates an application in a receiver. Additional information in the trigger message allows filtering or prioritization techniques to be applied at the receiver. Examples of possible use include the forcing of the display of information to warn of severe weather conditions and advising of extreme content in the TV programme. In an interactive system, a message or icon might be displayed inviting on-line access to vote, to register an interest in an advertised product, or to browse programme-related content