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

• US 20050147128A1
• Filed: 03/02/2005
• Published: 07/07/2005
• Est. Priority Date: 02/23/1999
• 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: Starr, Thomas J.J.
• Granted Patent: US 7,564,797 B2
• Time in Patent Office: Days
• US Class Current: 370/480
• 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

1-11. -11. (canceled)

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

(a) interfacing a transceiver unit with said single twisted-pair telephone transmission line;

(b) operating said transceiver unit to monitor the level of signal power in each of the predefined frequency bands for which said transceiver unit is pre-configured to transmit and receive communication signals;

(c) operating said transceiver unit to identify the lowest of said predefined frequency bands to have a signal power level that is less than a predetermined threshold signal power level; and

(d) operating said transceiver unit to transmit and receive communication signals over said single twisted-pair telephone transmission line within the predefined frequency band identified by said transceiver unit so as to establish a separate communication channel on said single twisted-pair telephone transmission line.

13. A method according to claim 12, wherein step (a) is accomplished by means of at least one contrivance selected from the group consisting of a network interface device (NID) and a wall jack.

14. A method according to claim 12, wherein said transceiver unit is a digital added main line (DAML) unit.

15. A method according to claim 14, wherein said digital added main line (DAML) unit includes a telephone integrated therewith.

16. A method according to claim 14, wherein said digital added main line (DAML) unit includes a digital signal processing (DSP) circuit.

17. A method according to claim 12, wherein said predefined frequency bands are separate from each other within the overall frequency spectrum.

18. A method according to claim 12, wherein each of said predefined frequency bands respectively has a lower limit frequency level that is greater than 4 kilohertz.

19. A method according to claim 12, wherein said predetermined threshold signal power level corresponds with the expected minimum level of signal power that would be attributable to any other transceiver unit that had previously established a communication channel on said single twisted-pair telephone transmission line.

20. A method according to claim 12, said method further comprising the steps of:

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

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

21. A method according to claim 12, said method further comprising the steps of:

(e) interfacing an additional transceiver unit with said single twisted-pair telephone transmission line;

(f) operating said additional transceiver unit to monitor the level of signal power in each of the predefined frequency bands for which said additional transceiver unit is pre-configured to transmit and receive communication signals;

(g) operating said additional transceiver unit to identify the lowest of said predefined frequency bands to have a signal power level that is less than said predetermined threshold signal power level; and

(h) operating said additional transceiver unit to transmit and receive communication signals over said single twisted-pair telephone transmission line within the predefined frequency band identified by said additional transceiver unit so as to establish another separate communication channel on said single twisted-pair telephone transmission line.

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

(a) interfacing a transceiver unit with said single twisted-pair telephone transmission line;

(b) operating said transceiver unit to successively monitor the respective levels of signal power in the predefined frequency bands for which said transceiver unit is pre-configured to transmit and receive communications signals, starting with the lowest of said predefined frequency bands;

(c) operating said transceiver unit to identify the lowest of said predefined frequency bands to have a signal power level that is less than a predetermined threshold signal power level; and

(d) operating said transceiver unit to transmit and receive communication signals over said single twisted-pair telephone transmission line within the predefined frequency band identified by said transceiver unit so as to establish a separate communication channel on said single twisted-pair telephone transmission line.

23. A method according to claim 22, wherein said transceiver unit is a digital added main line (DAML) unit.

24. A method according to claim 23, wherein said digital added main line (DAML) unit includes a digital signal processing (DSP) circuit.

25. A method according to claim 22, wherein said predefined frequency bands are separate from each other within the overall frequency spectrum.

26. A method according to claim 22, wherein each of said predefined frequency bands respectively has a lower limit frequency level that is greater than 4 kilohertz.

27. A method according to claim 22, wherein said predetermined threshold signal power level corresponds with the expected minimum level of signal power that would be attributable to any other transceiver unit that had previously established a communication channel on said single twisted-pair telephone transmission line.

28. A method according to claim 22, said method further comprising the steps of:

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

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

29. A method according to claim 22, said method further comprising the steps of:

(e) interfacing an additional transceiver unit with said single twisted-pair telephone transmission line;

(f) operating said additional transceiver unit to successively monitor the respective levels of signal power in the predefined frequency bands for which said additional transceiver unit is pre-configured to transmit and receive communication signals, starting with the lowest of said predefined frequency bands;

(g) operating said additional transceiver unit to identify the lowest of said predefined frequency bands to have a signal power level that is less than said predetermined threshold signal power level; and

(h) operating said additional transceiver unit to transmit and receive communication signals over said single twisted-pair telephone transmission line within the predefined frequency band identified by said additional transceiver unit so as to establish another separate communication channel on said single twisted-pair telephone transmission line.

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

(a) interfacing a transceiver unit with said single twisted-pair telephone transmission line;

(b) operating said transceiver unit to begin successively monitoring the respective levels of signal power in the predefined frequency bands for which said transceiver unit is pre-configured to transmit and receive communications signals, starting with the lowest of said predefined frequency bands;

(c) operating said transceiver unit to discontinue the successive monitoring as soon as one of said predefined frequency bands is identified to have a signal power level that is less than a predetermined threshold signal power level; and

(d) operating said transceiver unit to transmit and receive communication signals over said single twisted-pair telephone transmission line within the predefined frequency band identified by said transceiver unit so as to establish a separate communication channel on said single twisted-pair telephone transmission line.

31. A method according to claim 30, wherein said predefined frequency bands are separate from each other within the overall frequency spectrum.