Hybrid fiber-coax system having at least one digital fiber node and increased upstream and downstream bandwidth
CA 2205244 C · Owner: At&T Corp. · Inventors: Dail, James E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Noise is reduced and bandwidth may be increased in a CATV transmission system by modulating a portion of subscriber-generated upstream signals to a high frequency band (e.g. 750-100 MHz) and then digitally regenerating such signals. To further reduce noise, the digitally regenerated upstream signals are transmitted by in a baseband digital format to the head end (120) via a digital E/O converter (330). Increased downstream bandwidth is obtained by modulating a portion of the downstream signals to a higher frequency band (e.g. 500-750 MHz) and then digitally regenerating such signals.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed May 13, 1997 and granted February 6, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 13, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 13, 2019.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.