Abstract: The present invention relates to a master transceiver circuit meant to be coupled by a telephone line to a slave transceiver circuit, the master circuit including a digital phase-locked loop for reconstructing a clock from an incoming bit flow, the phase difference between the reconstructed clock and an internal clock corresponding to the content of a phase counter of the phase-locked loop. The circuit includes a bit counter clocked by the internal clock, initialized upon transmission of a predetermined signal, and stopped upon detection of the return of the predetermined signal transmitted back by the slave transceiver circuit; and means for calculating the delay introduced by the telephone line based on the contents of the phase and bit counters.

Abstract: A telephone includes a SIM card reader which receives SIM cards. The SIM card may contain two or more telephone numbers for which the phone is activated. One of the numbers may be a temporary number which is linked in use to, for example, a time period. By providing the capability of having two or more numbers on a SIM card, a single phone may respond to incoming calls for a different number of telephone numbers.