of the communicating device to the first application is granted or refused wherein if the arbitration requires an authentication of the communicating device the access control means instructs the authentication means to authenticate the communicating device application_number US 27596406 A description fig6 illustrates a security architecture in accordance with one embodiment of the invention the bluetooth protocol stack 100 is illustrated it includes lower layers including the link layer 106 a lowest multiplexing protocol layer 108 such as the l2cap layer a higher multiplexing protocol layer 110 such as the rfcomm layer 116 and an application layer 118 also illustrated are the user interface 130 a security manager 120 a service database 122 and a device database 124 the link layer 106 is directly connected to the lowest multiplexing protocol 108 access to the higher multiplexing protocol 110 and the applications services 118 from the link layer can only be achieved via the lowest multiplexing protocol layer 108 the lowest multiplexing protocol layer 108 is directly connected to the higher multiplexing protocol 110 and also directly connected to application 1183 access to the application 1183 can be made directly by the lowest multiplexing protocol whereas access to applications 1181 and 1182 can only be made via the higher multiplexing protocol 110 which is.