Cable television distribution network with video-on-demand transmission
US5517232A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 7, 1994 |
| Grant date | May 14, 1996 |
| Priority date | — |
| Expiry date | Jul 7, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J14/0298
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
It is desirable to offer the subscribers of a cable television distribution network, in addition to the cable TV service, a video-on-demand service. Since, in the foreseeable future, the fiber-optic portion of the cable television distribution networks will not extend to the subscribers (111) but will terminate in optical network terminations (ONT.sub.i) from which a respective optical access network (108-110) will extend to the subscribers, the problem arises how to transmit the entirety of subscriber-assigned video signals to the subscribers so that the latter can receive the requested video signals. According to the invention, the transmission from the center (100) through the fiber-optic distribution network (101-107) to the optical network terminations (ONT.sub.i) is digital, using time- and wavelength-division multiplexing. In each optical network termination, only that portion of subscriber-assigned video signals is removed which is intended for subscribers connected to the optical network termination (ONT.sub.i). The removed subscriber-assigned video signals are modulated onto subcarriers (M.sub.1 -M.sub.6) and frequency-division-multiplexed with the cable TV signals which …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.