Passive distributed filter system and method

• US 5,848,150 A
• Filed: 02/26/1997
• Issued: 12/08/1998
• Est. Priority Date: 02/26/1997
• Status: Expired due to Term

• Current Assignee: RPX Corporation
• Original Assignee: Paradyne Corporation (Dasan Networks Incorporated)
• Inventors: Bingel, Thomas J.
• Primary Examiner(s): Zele, Krista
• Assistant Examiner(s): APPIAH, CHARLES NANA
• Application Number:
  US08/805,606
• Time in Patent Office: 650 Days
• Field of Search: 379/93.01, 379/93.09, 379/402, 379/350, 379/93.05, 379/215, 379/184, 379/90.01, 333/17.1, 333/201, 333/202
• US Class Current: 379/399.01
• CPC Class Codes: H04M 11/062 using different frequency bands for speech and other data

Abstract

A plurality of passive distributed POTS filters (DPF) are associated with a respective plurality of POTS communications devices and decouple a POTS channel from a telephone connection, while permitting and not interfering with a second communications channel (e.g., DSL, ADSL, SDSL, RADSL, VADSL, etc.) on the telephone connection that is utilized by a modem. In architecture, the DPF system includes a plurality of POTS communications devices, such as telephones, and a plurality of the DPFs corresponding respectively with and connecting each of the POTS communications devices to the telephone connection. Each of the DPFs comprise an automatic control mechanism and a POTS filter. The automatic control mechanism is configured to isolate the POTS filter when a respective POTS communications device is on-hook. Each DPF is configured to permit POTS communications over a POTS channel on the telephone connection with the respective POTS communications device when the POTS communications device is off-hook. Furthermore, a second communications device, such as a DSL (e.g., ADSL, SDSL, RADSL, VADSL, etc.) communications device, is connected to the telephone connection and communicates signals over a second channel. The POTS and second channel are communicated over the telephone connection concurrently without appreciable interference.

Claims

1. A passive distributed filter for enabling decoupling of first and second simultaneous communications channels on a telephone connection, comprising:

a first channel filter configured to decouple a first channel from a combined signal having said first channel and a second channel on said telephone connection; and

an automatic control mechanism configured to isolate said first channel filter from said telephone connection when a first channel device connected thereto is on-hook and configured to interface said first channel filter with said telephone connection when said first channel device is off-hook.

2. The filter of claim 1, wherein said first channel filter is a POTS filter and said first channel is a POTS channel.

3. The filter of claim 1, wherein said first and second channels utilize different frequency ranges.

4. The filter of claim 1, wherein said first channel filter comprises a balanced 5^th order Chebyshev filter with a tuning circuit configured to enhance telephone sidetone response between about 1 KHz and about 3 KHz.

5. The filter of claim 1, wherein said first channel filter comprises:

cascaded first and second inductance circuits on each of tip and ring connections; and

a capacitance circuit in parallel with each second inductance circuit and configured to resonate with a corresponding second inductance circuit.

6. The filter of claim 2, wherein said second channel is a digital subscriber line (DSL) channel.

7. The filter of claim 5, wherein each of said first and second inductance circuits comprise a pair of mutually coupled inductors.

8. The system of claim 1, wherein said automatic control mechanism includes parallel opposing diodes connected to said telephone connection.

9. A telephone for connecting to a telephone connection having a POTS channel combined with a second communications channel, comprising:

a POTS filter configured to decouple said POTS channel from a combined signal having said POTS channel and said second communications channel on said telephone connection; and

an automatic control mechanism configured to isolate said POTS filter from said telephone connection when said telephone is on-hook and configured to interface said POTS filter with said telephone connection when said telephone is off-hook.

10. A distributed filter apparatus for connecting a POTS communication device to a telephone connection having a POTS channel and a second communications channel and for decoupling the POTS channel, comprising:

a housing with first and second ports, said first port adapted for connection to said telephone connection and said second port adapted for connection to said POTS communication device;

a POTS filter within said housing and connected to said second port, said POTS filter configured to decouple said POTS channel from a combined signal having said POTS channel and said second communications channel on said telephone connection; and

an automatic control mechanism within said housing and connecting said POTS filter and said first port, said automatic control mechanism configured to isolate said POTS filter from said telephone connection when said POTS communications device is on-hook and configured to interface said POTS filter with said telephone connection when said POTS communications device is off-hook.

11. The apparatus of claim 10, further comprising a third port associated with said housing configured to connect a second communications device adapted to utilize said second communications channel with said telephone connection.

12. A passive distributed filter system for enabling decoupling of first and second communications channels on a telephone connection, comprising:

a plurality of first communications devices;

a plurality of distributed filters corresponding respectively with and connecting each of said first communications devices to said telephone connection, each said distributed filter comprising an automatic control mechanism and a first channel filter, said automatic control mechanism configured to isolate said first channel filter when a respective first communications device is inactive, said distributed filter configured to interface communications on a first channel on said telephone connection with said respective first communications device when said first communications device is active; and

a second communications device connected to said telephone connection and communicating signals over a second channel.

13. The system of claim 12, wherein said first channel filter is a POTS filter.

14. The system of claim 12, wherein said first channel is a POTS channel and said second channel is a DSL channel.

15. The system of claim 12, wherein said first and second channels utilize different frequency ranges.

16. The system of claim 12, wherein said first channel filter comprises a balanced 5^th order Chebyshev filter with a tuning circuit configured to enhance frequency response between about 1 KHz and about 3 KHz.

17. The system of claim 12, wherein said first channel filter comprises:

cascaded first and second inductance circuits on each of tip and ring connections; and

a capacitance circuit in parallel with each second inductance circuit and configured to resonate with a corresponding second inductance circuit.

18. The system of claim 14, wherein said automatic control mechanism includes parallel opposing diodes connected to said telephone connection.

19. A passive distributed POTS filter system for enabling decoupling of a POTS channel and a second communications channel on a telephone connection, comprising:

a plurality of POTS communications devices;

a plurality of distributed POTS filters corresponding respectively with and connecting each of said POTS communications devices to said telephone connection, each said distributed POTS filter comprising an automatic control mechanism and a POTS filter, said automatic control mechanism configured to isolate said POTS filter when a respective POTS communications device is on-hook, said distributed POTS filter configured to permit POTS communications over a POTS channel on said telephone connection with said respective POTS communications device when said POTS communications device is off-hook; and

a second communications device connected to said telephone connection and communicating signals over a second channel, said POTS and second channels being communicated over said telephone connection concurrently.

20. The system of claim 19, wherein said second channel is a DSL channel.

21. The system of claim 19, wherein said POTS filter comprises a balanced 5^th order Chebyshev filter with a tuning circuit configured to enhance frequency response between about 1 KHz and about 3 KHz.

22. The system of claim 19, wherein said POTS filter comprises:

cascaded first and second inductance circuits on each of tip and ring connections; and

a capacitance circuit in parallel with each second inductance circuit and configured to resonate with a corresponding second inductance circuit.

23. A method for implementing a passive distributed filter system for enabling decoupling of first and second communications channels on a telephone connection at a plurality of sites, comprising the steps of:

interfacing a plurality of first channel communications devices with said telephone connection using a distributed filter, said first channel communications devices configured to communicate over said telephone connection via a first channel, said distributed filter comprising an automatic control mechanism and a first channel filter, said automatic control mechanism configured to isolate said first channel filter when a respective first communications device is inactive, said distributed filter configured to interface communications on a first channel on said telephone connection with said respective first communications device when said first communications device is active; and

interfacing a second channel communications device to said telephone connection, said second channel communications device configured to communicate over said telephone connection via a second channel; and

permitting noninterfering simultaneous communications via said first and second channels over said telephone connection.

24. The method of claim 23, further comprising the step of using POTS filters as said first channel filters and a POTS channel as said first channel.

25. The method of claim 23, further comprising the step of utilizing different nonoverlapping frequency ranges for said first and second channels.

26. The method of claim 23, further comprising the steps of:

utilizing a POTS channel as said first channel; and

utilizing a digital subscriber line (DSL) channel as said second channel.

27. The method of claim 23, further comprising the step of utilizing a tuning circuit in said distributed filter to enhance frequency response between about 1 KHz and about 3 KHz.