Optimizing upstream transmission in a cable television distribution plant
US6725462B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 19, 2000 |
| Grant date | Apr 20, 2004 |
| Priority date | — |
| Expiry date | Apr 19, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/6168
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for reducing delay distortion of upstream transmissions in a cable television (CATV) distribution plant. Upstream transmission in a CATV distribution plant, i.e., from the customer premises toward the head-end, is made difficult by delay distortion caused by diplexing filters used in bi-directional amplifiers and other components in the CATV distribution plant. A database storing information relating to each cable modem (CM) in the CATV distribution plant is maintained, and the delay distortion for each upstream transmission is calculated using information queried from the database. Delay distortion in the upper portion of the upstream bandwidth in a CATV distribution plant is preferably minimized by assigning CMs having a transmission path that causes relatively minimal delay distortion to the upper portion of the upstream bandwidth. Alternatively, the upper portion of the upstream bandwidth is preferably assigned to the largest number of CMs that have the same number of bi-directional amplifiers in their respective transmission paths. For either frequency assigning technique, a fixed equalizer may be used to further minimize delay distortion. Alternatively,…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.