Abstract: A DSL communication method is used for interconnecting a user and a center by using a 2-wire telephone line and a DSL communications technology so that the user and the center perform an intercommunication. The DSL communication method comprises the step of monitoring a signal-to-noise ratio of an accepted DSL, the step of judging whether or not the signal-to-noise ratio is within a predetermined range, and the step of interrupting the intercommunication once and thereafter reconnecting the user and the center, when the signal-to-noise ratio is judged not to be within the predetermined range for a duration longer than a reference time.

Abstract: A communication control system equipped with an efficient and economical rescue architecture is provided. A rescue bus is connected to units in a multiple formation and is used for rescue from a fault. A line switch connects a signal in a channel on a line and a signal processing part that processes the signal in normal operation, and disconnects the signal from the signal processing part when a fault has occurred. A rescue bus connecting switch connects the line and the rescue bus when the fault has occurred. A rescue switch connects the rescue bus and a backup signal processing part that processes the signal instead of a faulty unit. A communication units includes a switch part made up of the above switches and the signal processing part. A rescue unit includes a switch part made up of the above switches and the backup signal processing part, and performs a complete rescue or a provisional rescue. A monitor control device monitors fault occurrence and controls the switch part.

Abstract: A DSL communication method is used for interconnecting a user and a center by using a 2-wire telephone line and a DSL communications technology so that the user and the center perform an intercommunication. The DSL communication method comprises the step of monitoring a signal-to-noise ratio of an accepted DSL, the step of judging whether or not the signal-to-noise ratio is within a predetermined range, and the step of interrupting the intercommunication once and thereafter reconnecting the user and the center, when the signal-to-noise ratio is judged not to be within the predetermined range for a duration longer than a reference time.

Abstract: A communication control system equipped with an efficient and economical rescue architecture is provided. A rescue bus is connected to units in a multiple formation and is used for rescue from a fault. A line switch connects a signal in a channel on a line and a signal processing part that processes the signal in normal operation, and disconnects the signal from the signal processing part when a fault has occurred. A rescue bus connecting switch connects the line and the rescue bus when the fault has occurred. A rescue switch connects the rescue bus and a backup signal processing part that processes the signal instead of a faulty unit. A communication units includes a switch part made up of the above switches and the signal processing part. A rescue unit includes a switch part made up of the above switches and the backup signal processing part, and performs a complete rescue or a provisional rescue. A monitor control device monitors fault occurrence and controls the switch part.

Abstract: A telecommunications system and xDSL controller which quickly switch line interface circuits without interrupting the communication when some line error condition is detected, providing higher service quality and improved maintainability. A working package comprises a plurality of line interface controllers which control signal transmission and reception over subscriber lines. A protection package is prepared as a replacement for the working package, which would be used if a line failure occurred at one of the line interface controllers in the working package. A line failure detector detects such a line failure, which causes a line switching unit to check the current operating status of each line interface controller. The line switching unit reroutes line signals from the working package to the protection package, based on the current operating status that is observed.