An access control system is described and includes a server, a controller for regulating the accessibility of an entrance, and a mobile device having an application for user to trigger an access authentication process, means for collecting biometric information of the user, and a BLUETOOTH module to establish a BLUETOOTH communication link between the mobile device and the controller. The controller includes a communication module for connecting the controller to the server and mobile device for receiving updates on user access credentials, an access module for activating/deactivating a barrier of entrance, and a microprocessor for verifying the received user access credentials, generating an door execution command, and uploading the entrance status to the server.