Method of and apparatus for performing line characterization in a non-idle mode in a subscriber line communication system

A method of characterizing a subscriber line in a communication system including a first modem and a second modem coupled via the subscriber line and communicating data on a communication channel, the method comprising:

• providing a test signal on a control channel distinct from the communication channel from the first modem to the second modem across the subscriber line under a plurality of conditions;
• receiving the test signal with the second modem under the conditions;
• analyzing the test signal received by the second modem to generate a characterization signal for each of the conditions;
• wherein the test signal is a chirp signal.

A method of characterizing a subscriber line in a communication system including a first modem and a second modem coupled via the subscriber line and communicating data on a communication channel, the method comprising:

• providing a test signal on a control channel distinct from the communication channel from the first modem to the second modem across the subscriber line under a plurality of conditions;
• receiving the test signal with the second modem under the conditions;
• analyzing the test signal received by the second modem to generate a characterization signal for each of the conditions;
• repeating the providing, receiving, analyzing, and storing steps at particular times of the day.

A digital subscriber line modem, comprising:

• a data line access coupled to a subscriber line;
• an equalizer coupled to the data line access, the equalizer having a response in accordance with equalizer control signals;
• a line characterization circuit coupled to the equalizer, the line characterization circuit receiving a subscriber line signal on the subscriber line while the modem is in a non-idle mode and the line characterization circuit analyzing the line signal to generate the equalizer control signals, the line characterization circuit storing the equalizer control signals, wherein the line characterization circuit receives the line signals when the subscriber line has a particular parameter, the equalizer control signals being stored with respect to the particular parameter;
• and
• a retrain circuit, wherein the retrain circuit utilizes the equalizer control signals stored by the line characterization circuit to configure the digital subscriber line modem.

A method of characterizing a subscriber line in a communication system including a first modem communicating with a second modem across the subscriber line, the method comprising:

• performing a non-destructive characterization task on the subscriber line under a plurality of conditions;
• measuring parameters associated with the characterization tasks to obtain a result for each of the conditions;
• and
• storing the result for each of the conditions, the result being related to characteristics of the subscriber line.

A digital subscriber line modem, comprising:

• a data line access coupled to a subscriber line;
• an equalizer coupled to the data line access, the equalizer having a response in accordance with equalizer control signals;
• a line characterization circuit coupled to the equalizer, the line characterization circuit receiving a subscriber line signal on the subscriber line while the modem is in a non-idle mode and the line characterization circuit analyzing the line signal to generate the equalizer control signals, the line characterization circuit storing the equalizer control signals, wherein the line characterization circuit receives the line signals when the subscriber line has a particular parameter, the equalizer control signals being stored with respect to the particular parameter, wherein the particular parameter is a time of day;
• and
• a retrain circuit, wherein the retrain circuit utilizes the equalizer control signals stored by the line characterization circuit to configure the digital subscriber line modem.