Settop terminal controlled return path filter for minimizing noise ingress on bidirectional cable systems
US5937330A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 18, 1997 |
| Grant date | Aug 10, 1999 |
| Priority date | — |
| Expiry date | Feb 18, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/102
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A device which eliminates all RF ingress noise from entering the CATV network in the upstream communication path includes a shunt filter, a detector and a filter with a bandwidth equal to the bandwidth of the upstream communication path. The device monitors signals transmitted in the upstream bandwidth and detects when a valid upstream communication is being transmitted. Upon detection of this valid signal, the shunt filter is switched out of the upstream communication path to allow the valid transmission to be sent. When the end of the valid transmission is detected and a predetermined delay has lapsed, the shunt filter is switched to block all upstream transmissions in the upstream communication bandwidth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.