Noise Reduction Apparatus with Isolation Transformers in an Internet Protocol Television System

• US 20110131617A1
• Filed: 11/30/2009
• Published: 06/02/2011
• Est. Priority Date: 11/30/2009
• Status: Active Grant

• Current Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Inventors: Olson, Gregory D.
• Granted Patent: US 8,661,478 B2
• Time in Patent Office: Days
• US Class Current: 725/82
• CPC Class Codes: H04L 12/2834 Switching of information between an external network and a home network access arrangements H04L12/2856
• CPC Class Codes: H04L 2012/2849 Audio/video appliances
• CPC Class Codes: H04M 7/0069 comprising a residential gateway, e.g. those which provide an adapter for POTS or ISDN terminals
• CPC Class Codes: H04N 21/426 Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/436 Interfacing a local distribution network, e.g. communicating with another STB or one or more peripheral devices inside the home
• CPC Class Codes: H04N 21/43615 Interfacing a Home Network, e.g. for connecting the client to a plurality of peripherals home Audio Video Interoperability [HAVI] data switching networks H04L12/2805
• CPC Class Codes: H04N 21/438 Interfacing the downstream path of the transmission network originating from a server, e.g. retrieving encoded video stream packets from an IP network
• CPC Class Codes: H04N 7/102 Circuits therefor, e.g. noise reducers, equalisers, amplifiers H04N7/108 takes precedence

Abstract

A residential gateway includes an Internet Protocol television (IPTV) network communication port and a first isolation transformer circuit. The IPTV network communication port is configured to receive a signal from an ITPV network. The first isolation transformer circuit is in communication with the IPTV network communication port. The isolation transformer is configured to receive the signal from the IPTV network communication port, and to transform a ground of the signal to float at a ground potential of a power source of the residential gateway.

Claims

1. A residential gateway comprising:

an Internet Protocol television (IPTV) network communication port configured to receive a signal from an ITPV network; and

a first isolation transformer circuit in communication with the IPTV network communication port, the isolation transformer configured to receive the signal from the IPTV network communication port, and to transform a ground of the signal to float at a first ground potential of a first power source of the residential gateway.

2. The residential gateway of claim 1 further comprising:

a first common-mode inductor connected in series between the IPTV network communication port and a first terminal of a transformer in the first isolation transformer circuit; and

a second common-mode inductor connected in series between the IPTV network communication port and a second terminal of the transformer, wherein the first and second common-mode inductors are configured to filter out high frequency noise in the signal from the IPTV network.

3. The residential gateway of claim 2 wherein the transformer is a unity gain transformer.

4. The residential gateway of claim 2 wherein the high frequency noise is common-mode noise.

5. The residential gateway of claim 1 further comprising:

a second communication port configured to transmit the signal to a device within a customer premises; and

a second isolation transformer circuit in communication with the second communication port, the second isolation transformer circuit configured to transmit the signal to the device, and to transform the ground of the signal at the second communication port to float at a second ground potential of a second power source of the device.

6. The residential gateway of claim 1 wherein the IPTV network communication port is selected from a group consisting of an RJ 45 communication port, an RJ 11 communication port, and a coaxial communication port.

7. A device comprising:

a transformer coupled to a network communication port of a residential gateway, the transformer configured to transform a first ground of a signal from an Internet Protocol television (IPTV) network at the network communication port of the residential gateway to float at a first ground potential of a power source of the residential gateway;

a first common-mode inductor connected in series with a first terminal of the transformer; and

a second common-mode inductor connected in series with a second terminal of the transformer, wherein the first and second common-mode inductors are configured to filter out high frequency noise in the signal from the IPTV network.

8. The device of claim 7 wherein the transformer is a unity gain transformer.

9. The device of claim 7 wherein the transformer is further configured to isolate the first ground of the signal from a second ground of the signal.

10. The device of claim 9 wherein the second ground of the signal has a second ground potential substantially equal to a third ground of a set-top box device.

11. The device of claim 7 wherein the high frequency noise is common-mode noise.

12. The device of claim 7 wherein the network communication port is selected from a group consisting of an RJ 45 communication port, an RJ 11 communication port, and a coaxial communication port.

13. A method in a residential gateway of isolating a signal from an Internet Protocol television (IPTV) network comprising:

receiving at a first network communication port the signal from the IPTV network;

filtering out high frequency noise in the signal from the IPTV network;

transforming at the first network communication port a first ground of the signal from the IPTV network via a first transformer to float at a first ground potential of a first power source of the residential gateway; and

isolating the signal within the residential gateway.

14. The method of claim 13 further comprising:

outputting at a second network communication port the isolated signal to a device within a customer premises;

transforming at the second network communication port the first ground of the isolated signal via a second transformer to float at a second ground potential of a second power source of the device; and

isolating the isolated signal to the device.

15. The method of claim 13 wherein the filtering out of the high frequency noise in the signal is performed via a first common-mode inductor connected in series with a first terminal of the first transformer, and a second common-mode inductor connected in series with a second terminal of the first transformer.

16. The method of claim 13 wherein the first transformer is a unity gain transformer.

17. The method of claim 13 wherein the high frequency noise is common-mode noise.

18. The method of claim 13 wherein the first network communication port is selected from a group consisting of an RJ 45 communication port, an RJ 11 communication port, and a coaxial communication port.