Method and system for combining symmetric DSL signals and voice signals

• US 6,693,916 B1
• Filed: 10/22/1999
• Issued: 02/17/2004
• Est. Priority Date: 10/22/1999
• Status: Expired due to Term

• Current Assignee: Benhov GmbH, LLC (Intellectual Ventures LLC)
• Original Assignee: Viadux, Inc
• Inventors: Kasmir, Seton P., Chaplik, Naom
• Primary Examiner(s): Nguyen; Chau
• Assistant Examiner(s): HYUN, SOON D
• Application Number:
  US09/425,472
• Time in Patent Office: 1,579 Days
• Field of Search: 370/494,493,495,488,352,485,480,481,487,490 375/222
• US Class Current: 370/485
• CPC Class Codes: H04M 11/062 using different frequency bands for speech and other data

Abstract

This invention provides a simplified communication system that transmits voice and SDSL signals between customer premise equipment (“CPE”) on a single twisted-pair line. The system preferably includes at least one combiner for combining voice and SDSL signals into a combined voice/SDSL signal that can be transmitted to the CPE on a single twisted pair of wires, preferably a pair of wires currently being used to transmit the voice signal to the CPE. One combiner is ideally located at a common wiring closet of the building where the CPE is located. The combiner is ideally coupled to the existing pair of wires for the voice signal. This eliminates the need to add another set of wires between the common wiring closet and the CPE for the SDSL signal. A second combiner, normally located at or near the CPE, separates the combined voice/SDSL signal into the separate voice and SDSL signals for processing by the CPE. The second and first combiners normally also combine and separate, respectively, the voice and SDSL signals transmitted from the CPE.

Claims

1. A system for communicating a telephony voice signal and an SDSL signal on a single combined line where the frequency spectrum of the telephony voice signal during steady state conditions and the frequency spectrum of the SDSL signal may overlap, and where the telephony voice signal may include a plurality of transients during non-steady state conditions, the system including:

a first combiner coupled to a telephone switch on a first voice line for communicating the telephony voice signal, and to a first SDSL device on a first data line for communicating the SDSL signal, the first combiner configured to communicate both the telephony voice signal and the SDSL signal on the single combined line without significant interference even when transients are present on the telephony voice signal and where the first SDSL device may be disrupted when such transients exist on the first data line; and

a second combiner coupled to a telephony device on a second voice line for communicating the telephony voice signal, to a second SDSL device on a second data line for communicating the SDSL signal, and to the first combiner via the single combined line for communicating both the telephony voice signal and the SDSL signal, the second combiner configured to communicate the telephony voice signal and the SDSL signal on the single combined line without significant interference even when transients are present on the telephony voice signal and where the second SDSL device may be disrupted when such transients exist on the second data line.

2. The system according to claim 1 wherein each of the first and the second combiner includes:

a voice signal processor coupled to the voice line of the combiner, and to the single combined line, configured to attenuate the frequency spectrum of the telephony voice signal from the voice line above a first predetermined cutoff frequency and attenuate the frequency spectrum of the combined voice and SDSL signal to the voice line above the first predetermined cutoff frequency; and

an SDSL signal processor coupled to the data line of the combiner, and to the single combined line, configured to attenuate the frequency spectrum of the combined voice and SDSL signal to the data line below a second predetermined cutoff frequency and attenuate the frequency spectrum of the SDSL signal from the data line below the second predetermined cutoff frequency.

3. The system according to claim 1, wherein the plurality of transients that may occur on the telephony voice signal includes the telephony device coupled to the second voice line going off-hook.

4. The system according to claim 2, wherein the plurality of transients that may occur on the telephony voice signal includes the telephony device coupled to the second voice line going off-hook.

5. The system according to claim 1, wherein the first combiner is substantially the same as the second combiner.

6. The system according to claim 2, wherein the voice signal processor includes a low pass filter having a cutoff frequency higher than the upper frequency spectrum of the telephony voice signal during steady state conditions.

7. The system according to claim 6, wherein the SDSL signal processor includes a high pass filter having a cutoff frequency higher than the upper frequency spectrum of the telephony voice signal during steady state conditions.

8. The system according to claim 7, wherein the high pass filter is a low order filter.

9. The system according to claim 8, wherein the high pass filter is formed of an inductor in parallel with the line, and two capacitors in series with the line.

10. The system according to claim 6, wherein the SDSL signal processor includes a high pass filter having a cutoff frequency higher than the upper frequency spectrum of the telephony voice signal during steady state conditions and higher than the cutoff frequency of the low pass filter.

11. The system according to claim 10, wherein the high pass filter and the low pass filter are both coupled to the single combined line.

12. The system according to claim 10, wherein the low pass filter includes a plurality of capacitors and a plurality of inductors and only one or more of the inductors of the low pass filter are coupled to the single combined line.

13. The system according to claim 12, wherein each of one or more inductors of the plurality of inductors of the low pass filter coupled closest to the voice line is coupled in parallel with a plurality of diodes.

14. The system according to claim 1, wherein the SDSL signal is modulated using a four level format.

15. The system according to claim 1, wherein the SDSL signal is modulated using a 2B1Q format.

16. The system according to claim 1, wherein the plurality of transients that may occur on the telephony voice signal includes the telephony device coupled to the second voice line going off-hook while a ring signal is present in the telephony voice signal.

17. A method for communicating a telephony voice signal and an SDSL signal on a single combined line where the frequency spectrum of the telephony voice signal during steady state conditions and the frequency spectrum of the SDSL signal may overlap, and where the telephony voice signal may include a plurality of transients during non-steady state conditions, the method comprising:

communicating the telephony voice signal on a first voice line between a telephone switch via the single combined line;

communicating the SDSL signal on a first data line between a first SDSL device via the single combined line without significantly corrupting or interrupting the SDSL signal and telephony voice signal even when transients are present on the telephony voice signal and where the first SDSL device may disrupted when said transients are present on the first data line;

communicating the telephony voice signal on a second voice line between a telephony device via the single combined line; and

communicating the SDSL signal on a second data line between a second SDSL device via the single combined line without significantly corrupting or interrupting the SDSL signal and telephony voice signal even when transients are present on the telephony voice signal and where the second SDSL device may disrupted when said transients are present on the second data line.

18. The method according to claim 17, wherein communicating the telephony voice signal on a first voice line and communicating the telephony voice signal on a second voice line include attenuating the frequency spectrum of the telephony voice signal from the associated voice line above a first predetermined cutoff frequency and attenuating the frequency spectrum of the SDSL signal to said voice line above the first predetermined cutoff frequency, and wherein communicating the SDSL signal on a first data line and communicating the SDSL signal on a second data line include attenuating the frequency spectrum of the telephony voice signal to the associated data line below a second predetermined cutoff frequency and attenuating the frequency spectrum of the SDSL signal from said data line below the second predetermined cutoff frequency.

19. The method according to claim 17, wherein the plurality of transients that may occur on the telephony voice signal includes the telephony device coupled to the second voice line going off-hook.

20. The method according to claim 17, wherein the SDSL signal is modulated using a four level format.

21. The method according to claim 17, wherein the SDSL signal is modulated using a 2B1Q format.

22. The method according to claim 18, wherein the plurality of transients that may occur on the telephony voice signal include the telephony device coupled to the second voice line going off-hook while a ring signal is present in the telephony voice signal.

23. The method according to claim 18, wherein the attenuation of the telephony voice signal includes the suppression of transients that are of a higher voltage than that of the telephony voice signal during steady state conditions.

24. The method according to claim 18, wherein the method of attenuating the telephony voice signal has a minimum effect on the SDSL signal.

25. The method according to claim 18, wherein the method of attenuating the SDSL signal is a low order attenuation method.