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

• US 6,324,167 B1
• Filed: 02/23/1999
• Issued: 11/27/2001
• Est. Priority Date: 02/23/1999
• Status: Expired due to Term

• Current Assignee: SBC Properties, L.P. (AT&T, Inc.)
• Original Assignee: Ameritech Corp. (AT&T, Inc.)
• Inventors: Starr, Thomas J. J.
• Primary Examiner(s): YAO, KWANG BIN
• Application Number:
  US09/255,969
• Time in Patent Office: 1,008 Days
• Field of Search: 370/480, 370/481, 370/482, 370/483, 370/485, 370/487, 370/489, 370/490, 370/493, 370/494, 370/495, 370/241, 370/250, 370/251, 379/90.01, 379/93.09, 379/269, 379/205, 379/206, 375/225, 375/227, 375/220, 375/222
• 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 of implementing a plurality of communication channels on a single twisted pair telephone connection comprising the steps of:

interfacing a first communication device with said telephone connection, said first communication device configured to communicate over said telephone connection on a first channel defined by a first frequency band;

interfacing a second communication device with said telephone connection, said second communication device configured to communicate with said telephone connection on a second channel said step of interfacing comprising monitoring the signal power of a second frequency band above said first frequency band and, if the detected signal power is below a predetermined level, then assigning said second channel to said second frequency band, else monitoring the signal power of a third frequency band above said first and second frequency bands and, if the detected signal power is below a predetermined level, then assigning said second channel to said third frequency band; and

interfacing a third communication device with said telephone connection, said third communication device configured to communicate with said telephone connection on a third channel, wherein said first, second, and third communication channels each reside in separate predetermined frequency bands.

2. The method of claim 1 wherein the step of interfacing said third communication device includes the step of:

monitoring the signal power of a second frequency band above said first frequency band and, if the detected signal power is below a predetermined level, then assigning said third channel to said second frequency band, else monitoring the signal power of a third frequency band above said first and second frequency bands and, if the detected signal power is below a predetermined level, then assigning said third channel to said third frequency band.

3. The method of claim 2 wherein the steps of monitoring the signal power of said second and third frequency bands includes the step of integrating and averaging the signal power over a predetermined time period.

4. In a network connection including a first communication device communicating with a network across a single twisted pair telephone line in a baseband POTS frequency band, a method of deriving additional communication channels over said single twisted pair telephone line comprising the steps of:

coupling a plurality of communication devices to said network connection;

detecting a communication request from one of said communication devices and, in response;

monitoring the signal quality in a series of predefined frequency bands successively higher than said POTS frequency band and configuring said respective one communication device to communicate with said network across a first of said series of predefined frequency bands wherein said signal quality is above a threshold value and, if the signal quality deteriorates below said threshold value, monitoring the signal quality in each successive frequency band of said remaining series of predefined frequency bands, and reconfiguring said respective one communication device to communicate with said network across one of said successive frequency bands wherein said signal quality is above said threshold value.

5. The method of claim 4 wherein said first communication device and said plurality of communication devices are located at a single customer premises and communicate with said network via a single twisted pair telephone line.

6. The method of claim 4 wherein said first communication device is located at a first customer premises and at least one of said plurality of communication devices are located at a second customer premises, said first and second customer premises communicating with said network via the same twisted pair telephone line.

7. A communications arrangement between a PSTN and a customer premises connected by a single twisted pair telephone transmission line comprising:

a first communication device configured to communicate across said telephone transmission line on a first channel defined by a first frequency band;

a second communication device configured to communicate across said telephone transmission line on a second channel; and

a third communication device configured to communicate across said telephone transmission line on a third channel, wherein said first, second, and third communication channels each reside in separate predefined frequency bands, said second and third communication channels being assigned a respective frequency band in response to a respective communication request from said respective second or third communication device by sequentially monitoring the signal quality in each successively higher frequency band and configuring said respective second or third communication device to communicate across said telephone transmission line within a first of said predefined frequency bands wherein said signal quality is above a threshold value.

8. The arrangement of claim 7 wherein said first communication device is a telephone and said first frequency band is the baseband POTS frequency band.

9. The arrangement of claim 7 wherein said second and third communication devices are configured to communicate across said telephone transmission line using quadrature amplitude modulated digital signals.