Methods and filter for isolating upstream ingress noise in a bi-directional cable system
First Claim
1. An upstream ingress filter for isolating upstream ingress noise on a bi-directional cable system, said cable system comprising a cable control unit, a plurality of cables, and a plurality of cable access units, each one of said plurality of cables having an upstream band and a downstream band for carrying upstream signals and downstream signals, respectively, each one of said plurality of cable access units containing at least one upstream ingress filter, each of said upstream ingress filters comprising:
- a DC switching element for changing a DC voltage on the cable system at said one of said plurality of cable access unit, said DC switching element being connected in parallel to said one of said plurality of cables; and
a switchable notch filter that switches ON and OFF in response to said DC switching element, said notch filter acting to isolate upstream ingress by attenuating upstream signals in said upstream band when said upstream ingress filter is ON, said notch filter being connected in parallel to said one of said plurality of cables.
6 Assignments
0 Petitions
Accused Products
Abstract
An upstream ingress filter (300) for isolating upstream ingress noise on a bi-directional cable system having an upstream band and a downstream band for carrying upstream signals and downstream signals, respectively. The upstream ingress filter (300) includes a DC switching element (310) for changing the DC voltage on the cable system at said cable access unit and a switchable notch filter (340) that switches ON and OFF in response to the DC switching element. The notch filter isolates upstream ingress noise by attenuating upstream signals in the upstream band when the upstream ingress filter is ON. Both the DC switching element (310) and the notch filter (340) are connected in parallel to the cable (301).
27 Citations
10 Claims
-
1. An upstream ingress filter for isolating upstream ingress noise on a bi-directional cable system, said cable system comprising a cable control unit, a plurality of cables, and a plurality of cable access units, each one of said plurality of cables having an upstream band and a downstream band for carrying upstream signals and downstream signals, respectively, each one of said plurality of cable access units containing at least one upstream ingress filter, each of said upstream ingress filters comprising:
-
a DC switching element for changing a DC voltage on the cable system at said one of said plurality of cable access unit, said DC switching element being connected in parallel to said one of said plurality of cables; and a switchable notch filter that switches ON and OFF in response to said DC switching element, said notch filter acting to isolate upstream ingress by attenuating upstream signals in said upstream band when said upstream ingress filter is ON, said notch filter being connected in parallel to said one of said plurality of cables. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. An upstream ingress filter for isolating upstream ingress noise on a bi-directional cable system, said cable system comprising a cable control unit, a plurality of cables, and a plurality of cable access units, each one of said plurality of cables having an upstream band and a downstream band for carrying upstream signals and downstream signals, respectively, said upstream ingress filter comprising:
-
a DC switching element changing a DC voltage on the cable system at said cable access unit, said DC switching element connected in parallel to said one of said plurality of cables; and a switchable notch filter switching ON and OFF in response to said DC switching element, said notch filter acting to isolate upstream ingress by attenuating upstream signals in said upstream band when said upstream ingress filter is ON, said notch filter connected in parallel to said one of said plurality of cables.
-
Specification