One way data transmission system
Special services teletext communications system
Interface method and apparatus
Frequency generation for multiplexed analog component color television encoding and decoding
Synchronization recovery in a communications system
Data transmission system
Method and apparatus for providing secure electronic communications
Digital signal transmitting system
Restoring framing in a communications system
Communication of individual messages to subscribers in a subscription television system
ApplicationNo. 160827 filed on 12/03/1993
US Classes:725/137, Teletext348/467, Data format348/468, Including teletext decoder or display380/212, Plural video stream multiplexing713/160, Packet header designating cryptographically protected data725/61Interactive program selection
ExaminersPrimary: Barron, Gilberto Jr.
Attorney, Agent or Firm
International ClassesH04L 009/00
AbstractA teletext system provides teletext services and teletext support services in a multiservice communication system. Multiplexed data streams for a plurality of services, including teletext data, are transmitted in a sequence of frames between a transmitter location and a receiver location. Teletext information is transmitted in the format of a header packet and a data packet. The header packet contains information identifying the teletext information according to page number as well as other filter fields, such as language, time zone, etc. By appropriate selection of the values of the filter fields, the operator is afforded greater flexibility in providing a variety of classes of service and service support to subscribers. In addition, the system may be easily be reconfigured to support the addition of services or the cancellation of services.