An access point from a mobile communications system to an external system is selected at a service node of the mobile communications system based on at least two or three grounds of selection: the subscription data of a mobile subscriber stored in the mobile communication system or an access point selection data given by a user in a service request, or on other grounds. A system for converting a digital signal so as to send a radiofrequency analog signal carrying the information of the digital signal is also described. In some embodiments, one or more portions of the partition frame are electrified to shock an occupant in a restricted area attempting to gain access to a permitted area through an opening in the partition. Embodiments of this check stand may have an output module that is a carousel or a turntable. The ignitor may be immersed in or substantially adjacent the charge of exothermic material. The auxiliary cooling circuit comprises one or more auxiliary radiators which are connected parallel to the radiator of the auxiliary circuit and which are constituted by motor-vehicle body components.