Upstream data transmission system for cable television
US5535206A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 1995 |
| Grant date | Jul 9, 1996 |
| Priority date | — |
| Expiry date | Feb 7, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/6168
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A cable television upstream data transmission system provides a plurality of time slots synchronized to the downstream symbol clock for use by subscriber terminals in upstream data transmission. The width and number of time slots are controlled by a pair of downloadable values to accommodate dynamic changes of the cable system. A transmission modulator used within the subscriber terminal produces an upstream transmission carrier having a frequency locked to the symbol clock. The frequency of the carrier signal produced by the transmission modulator is programmably controlled by a plurality of program values which are selected to provide frequency and phase lock of the modulator's carrier to the symbol clock.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.