Abstract: A user of a telephone service selects the quality level of a connection by manually specifying the desired quality level, automatically setting up the call with the specified quality level. To assist the user when selecting the quality, a voice sample of the user or a pre-recorded voice sample with specified quality levels may be played back to the user as a reference before the selection of a quality level. Alternatively, the user may be informed about transmission parameters associated with specified quality levels before the selection of a quality level. The method may be carried out by a service control point and a service switching point in a telecommunication network.

Abstract: A device for providing phase synchronism of a transit station in a digital telecommunication network, comprising within a phase-locked loop a voltage-controlled oscillator that has an output arranged to supply a station clock signal and a control input actuated by line clock signals pertaining to a plurality of incoming lines from other transit stations in the telecommunication network and a phase comparator that is arranged to compare the phase of the station clock signal with the phases of the line clock signals and has an output connected to the control input of the voltage-controlled oscillator via a loop filter.