Access control system for radio and facial recognition

A method for operating a system for controlling access to an access-restricted zone in a building or a site, the system comprising a transmitting and receiving device, a memory device, a processor and an image processing device, the method comprising:

• for each user present in a public zone from which a user may request access to the access-restricted zone, receiving a device-specific identifier of a user's mobile electronic device by the transmitting and receiving device when the user's mobile electronic device is located in the public zone;
• storing the received identifier of each mobile electronic device in the memory device as belonging to a present user, the memory device including a database in which a plurality of user profiles of access-authorized users is stored, each user profile including a reference template of facial features for each respective user;
• generating a real-time template for facial features of a first present user from a camera image of the first present user produced by a camera of the image processing device, if a presence of the first present user is recognized in a detection area of the camera when the first present user requests access to the access-restricted zone, wherein the real-time template is generated by the image processing device;
• and
• searching user profiles stored in the database including reference templates, wherein the user profiles are searched only if the user profiles are assigned to present users in the public zone whose received identifiers are stored in the memory device, comparing the real-time template to one of the reference templates to a selected degree of similarity of facial features, wherein, in case of a match, the system grants the first present user access to the access-restricted zone and denies access when there is no match.