PCT No. PCT/FR94/01242 Sec. 371 Date Apr. 24, 1996 Sec. 102(e) Date Apr. 24, 1996 PCT Filed Oct. 25, 1994 PCT Pub. No. WO95/12293 PCT Pub. Date May 4, 1995A digital radiotelephone installation with mobile terminals includes a fixed base transceiver station, which is an element of the network, and mobile telephone terminals at least some of which are designed to be unable to access the network until a user has inserted therein an extractable personalized smart card ("SIM card"). Each mobile terminal is designed to receive, in addition to the extractable "conventional" SIM card, another, auxiliary SIM smart card which remains in the mobile terminal at all times. The auxiliary SIM card corresponds to the same personalized subscription as the conventional SIM card. The extractable conventional SIM card takes precedence over the auxiliary SIM card when it is inserted into said mobile terminal, however, and has the same functionality as the latter. The auxiliary SIM card is assigned by the network or by said terminal only specific predefined services, such as typically an answering function and/or a short messages service function, the predefined services possibly including outgoing call restriction.