Mixed analog-digital service distribution system and method
US5982413A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 3, 1996 |
| Grant date | Nov 9, 1999 |
| Priority date | — |
| Expiry date | Apr 3, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/22
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
By transmitting an analog CATV signal output from a CATV-HE (CAble TeleVision-Head End) to an HDT (Host Digital Terminal), an analog transmission channel for transmitting the analog CATV signal to an ONU (Optical Network Unit) is included in a path housing a digital transmission channel for transmitting a digital service signal for individual distribution service to the ONU. Furthermore, a digital service signal for multicast service is modulated and converted into an analog service signal by a modulator in the HDT. Then, the converted signal is mixed with the analog CATV signal, and transmitted to the ONU. Accordingly, each of the ONUs is equipped with only a built-in modulator for modulating the digital service signal for individual distribution service.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.