Digital subscriber line induction neutralizing transformer network

• US 7,266,154 B2
• Filed: 05/10/2002
• Issued: 09/04/2007
• Est. Priority Date: 05/10/2002
• Status: Expired due to Fees

• Current Assignee: Southwestern Bell Telephone Company (AT&T, Inc.)
• Original Assignee: Southwestern Bell Telephone Company (AT&T, Inc.)
• Inventors: Gundrum, Russell F.
• Primary Examiner(s): Lugo; David B.
• Application Number:
  US10/143,130
• Publication Number:
  US 20030210747A1
• Time in Patent Office: 1,943 Days
• Field of Search: 375/257, 375/258, 336/15, 336/221
• US Class Current: 375/258
• CPC Class Codes: H04B 3/26 Improving frequency characteristic by the use of loading coils

Abstract

A digital subscriber line (DSL) induction-neutralizing transformer (INT) (28) for use in a DSL INT network (10) is provided. The DSL INT (28) includes a core (72) and a coil (74) that is electrically coupled to and wound around the core (72). The coil (74) includes approximately 100-200 feet of approximately 24-gauge wire. The core (72) and coil (74) add longitudinal inductance to a telecommunication line and reduce induced voltage levels at a non-digital subscriber line frequency on the telecommunication line. The DSL INT network (10), containing at least one DSL INT (28), and a method of routing DSL communication signals within the DSL INT network (10), are also provided.

Claims

1. A digital subscriber line induction neutralizing transformer for use in a digital subscriber line induction neutralizing transformer network comprising:

a core; and

a coil electrically coupled to and wound around said core and comprising approximately 100-200 feet of approximately 24 gauge wire;

said core and said coil adding longitudinal inductance to a telecommunication line and reducing induced voltage levels at a non-digital subscriber line frequency on said telecommunication line;

wherein said digital subscriber line induction neutralizing transformer does not include a screen or shield to prevent crosstalk interference.

2. A transformer as in claim 1 wherein adding longitudinal inductance comprises adding approximately 6 to 25 Henries of inductance to said telecommunication line.

3. A transformer as in claim 1 wherein said induced voltage levels are generated from a steady-state source or are surge-induced.

4. A transformer as in claim 1 wherein said core is a permeable ferromagnetic core formed from a ferromagnetic iron or nickel material.

5. A transformer as in claim 1 wherein said core and said coil neutralize at least 95% of approximately 50-100 volts on said telecommunication line instantaneously whether said induced voltage levels are generated from a steady-state source or are surge-induced.

6. A transformer as in claim 1 wherein said coil comprises category 5 Ethernet type telecommunication cable comprising tightly twisted wire pairs.

7. A transformer as in claim 1 wherein said coil is at least one of:

color-coated, unjacketed, plastic-insulated, or unshielded telecommunication cable.

8. A transformer as in claim 1 wherein said non-digital subscriber line frequency is approximately equal to 50 Hz or 60 Hz.

9. A digital subscriber line induction neutralizing transformer network comprising:

one or more remote terminals routing digital subscriber line communication signals to a plurality of customer terminals; and

one or more digital subscriber line circuits wherein at least one digital subscriber line circuit receives an excitation current from an induced voltage, said one or more digital subscriber line circuits comprising;

one or more transformer exciting networks electrically coupled to a remote terminal of said one or more remote terminals and supplying one or more low impedance paths to ground for said excitation current; and

a digital subscriber line induction neutralizing transformer electrically coupled to said one or more transformer exciting networks, the digital subscriber line induction neutralizing transformer comprising;

a core; and

a coil electrically coupled to and wound around said core and comprising approximately 100-200 feet of approximately 24 gauge wire;

said core and said coil adding longitudinal inductance to a telecommunication line and reducing induced voltage levels at a non-digital subscriber line frequency on said telecommunication line;

wherein said digital subscriber line induction neutralizing transformer does not include a screen or shield to prevent crosstalk interference.

10. A network as in claim 9 further comprising one or more central offices electrically coupled to said one or more remote terminals via one or more fiber optic cables and routing said digital subscriber line communication signals between said one or more remote terminals and a backbone network.

11. A network as in claim 9 wherein at least one transformer exciting network in the digital subscriber line induction neutralizing transformer network is a super transformer exciting network comprising a harmonic drainage reactor.

12. A network as in claim 9 wherein supplying one or more low impedance paths to ground said one or more transformer exciting networks reduce approximately 50 Hz or 60 Hz induced voltage levels and current levels.

13. A network as in claim 9 wherein a first transformer exciting network of said one or more transformer exciting networks is electrically coupled between a remote terminal and said digital subscriber line induction neutralizing transformer.

14. A network as in claim 9 wherein a second transformer exciting network of said one or more transformer exciting networks is electrically coupled at a customer terminal site.

15. A network as in claim 9 wherein said coil comprises category 5 Ethernet type telecommunication cable comprising tightly twisted wire pairs.

16. A method of routing digital subscriber line communication signals with a digital subscriber line induction neutralizing transformer network, said method comprising:

routing digital subscriber line communication signals between a backbone network and one or more remote terminals;

routing said digital subscriber line communication signals between one or more central offices and one or more digital subscriber line circuits;

receiving an induced voltage level and an excitation current;

supplying a first low impedance path-to-ground for said excitation current;

supplying a second low impedance path-to-ground for said excitation current;

neutralizing said induced voltage level in response to said excitation current using a digital subscriber line induction neutralizing transformer comprising;

a core; and

a coil electrically coupled to and wound around said core and comprising approximately 100-200 feet of approximately 24 gauge wire;

said core and said coil adding longitudinal inductance to a telecommunication line and reducing induced voltage levels at a non-digital subscriber line frequency on said telecommunication line;

wherein said digital subscriber line induction neutralizing transformer does not include a screen or shield to prevent crosstalk interference; and

routing said digital subscriber line communication signals to one or more customer terminals.

17. A method as in claim 16 wherein neutralizing said non-digital subscriber line frequency comprises adding approximately 6 to 25 Henries of inductance to said telecommunication line.