Time-division duplexing signal booster

A signal booster for time division duplex “TDD” signals in a TDD Digital subscriber line “DSL” environment comprising:

• first and second bidirectional terminals;
• an amplifier circuit arranged in a signal path between said first and second terminals to amplify TDD signals received at one of said first and second terminals for transmission from the other of said first and second terminals, said amplifier circuit being operable in a first configuration for amplifying TDD signals in one direction along the signal path and a second configuration for amplifying TDD signals in the opposite direction along the signal path;
• an analog to digital converter (ADC) which detects signals output from the respective amplifiers and convert them to digital output;
• and
• a control circuit arranged to use said digital output from the ADC to perform synchronization and detection of upstream “US”/downstream “DS” signals to identify a silent period in said signals and, in response to detecting a silent period, control said amplifier circuit to change configuration.