Method and system for conveying multiple calls on a single telephone line

• US 7,564,797 B2
• Filed: 03/02/2005
• Issued: 07/21/2009
• Est. Priority Date: 02/23/1999
• Status: Expired due to Fees

• Current Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Inventors: Starr, Thomas J. J.
• Primary Examiner(s): Yao; Kwang B
• Assistant Examiner(s): Skripnikov; Alex
• Application Number:
  US11/070,618
• Publication Number:
  US 20050147128A1
• Time in Patent Office: 1,602 Days
• Field of Search: 370478-497, 370241-259, 370216-228
• US Class Current: 370/250
• CPC Class Codes: H04J 1/02 Details
• CPC Class Codes: H04Q 11/04 for time-division multiplexing H04Q11/0001 takes precedence
• CPC Class Codes: H04Q 2213/13039 Asymmetrical two-way transmission, e.g. ADSL, HDSL
• CPC Class Codes: H04Q 2213/13076 Distributing frame, MDF, cross-connect switch
• CPC Class Codes: H04Q 2213/1319 Amplifier, attenuation circuit, echo suppressor
• CPC Class Codes: H04Q 2213/13381 Pair-gain system, digital loop carriers

Abstract

A system for implementing multiple communication channels on a single twisted pair transmission line is disclosed. The system derives additional communication channels by way of a separate transceiver unit for each derived line. Each transceiver unit communicates in a separate predetermined frequency band. Each transceiver unit, upon connection to the transmission line, automatically utilizes the lowest unoccupied frequency band by monitoring each frequency band for the presence of signal power. Thus, as many derived lines as will be supported by the customer transmission loop can be readily added.

Claims

1. A method for establishing at least one separate communication channel on a single twisted-pair telephone transmission line, the method comprising:

interfacing a first transceiver unit with the single twisted-pair telephone transmission line, wherein interfacing is accomplished via a network interface device (NID) or a wall jack;

operating the first transceiver unit to monitor a corresponding signal power level in each of a first plurality of predefined frequency bands for which the first transceiver unit is pre-configured to transmit and receive communication signals;

operating the first transceiver unit to identify a first available frequency bands comprising to a lowest frequency band of the first plurality of predefined frequency bands having the corresponding signal power level that is less than a predetermined threshold signal power level; and

establishing a first separate communication channel on the single twisted-pair telephone transmission line by operating the first transceiver unit to transmit and receive first communication signals over the single twisted- pair telephone transmission line within the first available frequency band.

2. The method according of claim 1, wherein the first transceiver unit is a digital added main line (DAML) unit.

3. The method of claim 2, wherein the digital added main line (DAML) unit includes a telephone integrated therewith.

4. The method of claim 2, wherein the digital added main line (DAML) unit includes a digital signal processing (DSP) circuit.

5. The method of claim 1, wherein the first plurality of predefined frequency bands comprise non-overlapping frequency bands.

6. The method of claim 1, wherein each of the first plurality of predefined frequency bands has a corresponding lower frequency limit that is greater than 4kilohertz.

7. The method of claim 1, wherein said predetermined threshold signal power level corresponds to an expected minimum signal power level of a second transceiver unit that had previously established a communication channel on the said single twisted-pair telephone transmission line.

8. The method of claim 1, further comprising:

connecting a device comprising at least one of a telephone, a computer, and a facsimile machine to the first transceiver unit; and

operating the device to transmit and receive communication signals, via the first transceiver unit, over the single twisted-pair telephone transmission line within the first separate communication channel.

9. The method of claim 1, further comprising

interfacing the second transceiver unit to the single twisted-pair telephone transmission line;

operating the second transceiver unit to monitor a corresponding signal power level in each of a second plurality of predefined frequency bands for which the second transceiver unit is pre-configured to transmit and receive communication signals;

operating the second transceiver unit to identify a second available frequency band comprising a lowest frequency band of the second plurality of predefined frequency bands having a corresponding signal power level that is less than the predetermined threshold signal power level; and

establishing a second separate communication channel on the single twisted-pair telephone transmission line by operating the second transceiver unit to transmit and receive second communication signals over the single twisted-pair telephone transmission line within the second available frequency band.

10. A method of establishing a separate communication channel on a single twisted-pair telephone transmission line, said method comprising:

interfacing a transceiver unit with the single twisted-pair telephone transmission line, wherein the transceiver unit is a digital added main line (DAML) unit;

operating the transceiver unit to successively monitor the corresponding signal power level in each of a first plurality of predefined frequency bands for which the first transceiver unit is pre-configured to transmit and receive communications signals;

operating the transceiver unit to identify a first available frequency band comprising a lowest of the first plurality of predefined frequency bands having a corresponding signal power level that is less than a predetermined threshold signal power level;

operating the transceiver unit to transmit and receive communication signals over the said single twisted-pair telephone transmission line within the first available frequency band to establish a separate communication channel on the single twisted-pair telephone transmission line.

11. The method of claim 10, wherein the digital added main line (DAML) unit includes a digital signal processing (DSP) circuit.

12. The method of claim 10, wherein the first plurality of predefined frequency bands are non-overlapping.

13. The method of claim 10, wherein each of the first plurality of predefined frequency bands has a corresponding lower frequency limit that is greater than 4kilohertz.

14. The method of claim 10, wherein the predetermined threshold signal power level corresponds to a minimum level of signal power of a transceiver unit that had previously established a communication channel on the single twisted-pair telephone transmission line.

15. The method of claim 10, further comprising:

connecting a device selected from the group consisting of a telephone, a computer, and a facsimile machine to said transceiver unit; and

operating the device to transmit and receive communication signals, via the transceiver unit, over said single twisted-pair telephone transmission line within the separate communication channel.

16. The method of claim 10, further comprising:

interfacing an additional transceiver unit with the single twisted-pair telephone transmission line;

operating the additional transceiver unit to successively monitor the corresponding signal power level in each of a second plurality of predefined frequency bands in which the additional transceiver unit is pre-configured to transmit and receive communication signals;

operating the additional transceiver unit to identify a second available frequency band comprising a lowest frequency band of the second plurality of predefined frequency bands having a signal power level that is less than the predetermined threshold signal power level; and

operating the additional transceiver unit to transmit and receive communication signals over the single twisted-pair telephone transmission line within the second available frequency band to establish another separate communication cannel on the single twisted-pair telephone transmission line.

19. The method of claim 10, wherein interfacing is accomplished via a wall jack.

20. The method of claim 10, wherein interfacing is accomplished via a Network Interface Device (NID).

17. A method of establishing at least one separate communication channel on a single twisted-pair telephone transmission line, said method comprising:

interfacing a transceiver unit with the single twisted-pair telephone transmission line;

identifying a lowest available frequency band by monitoring a corresponding signal power level in each of a plurality of predefined frequency bands for which the transceiver unit is pre-configured to transmit and receive communications signals, wherein the corresponding signal power level of the lowest available frequency band is less than a predetermined threshold signal power level, wherein each successively measured frequency band comprises a higher frequency range than each previously measure frequency band;

operating said transceiver unit to discontinue the successive monitoring after the lowest available frequency band is identified; and

operating the transceiver unit to transmit and receive communication signals over the signal twisted-pair telephone transmission line within the lowest available frequency band to establish a separate communication channel on the single twisted-pair telephone transmission line.

18. The method of claim 17, wherein the plurality of predefined frequency bands comprise non-overlapping frequency ranges.