Multiplex channels for continuous flow for numerical signal
US4688218A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 16, 1984 |
| Grant date | Aug 18, 1987 |
| Priority date | — |
| Expiry date | Jan 16, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2007/045
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A digital data pack transmission system is especially--but not exclusiveluseful in videotex or teletext transmission (i.e. videotext or teletext data is transmitted during intervals between segments of video signals). The inventive system uses a continuous transmission carrier. A plurality of data packs are individually included in each block of data which is periodically transmitted. Dummy packs are used to fill the blocks, if less than a full complement of packs is required. The time periods available for the transmission of blocks of data are exactly equal to or a little longer than the maximum length of the transmitted blocks. The beginning of each data block has a synchronization bit pattern which is constituted by a "bit sync" byte followed by a "byte sync" byte. Except for the synchronizing pattern, the signals are scrambled before transmission and descrambled upon receipt and recognization of the data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.