Access control system

An elevator access control method, comprising:

• receiving, at a building, an identification code from a mobile telephone;
• determining that the identification code is valid;
• as a result of the determining, transmitting a description of an optical code to the mobile telephone;
• reading the optical code from a screen of the mobile telephone, the mobile telephone being borne by a visitor;
• and
• based on the reading of the optical code, granting to the visitor access to an elevator at the building.

An elevator system component comprising:

• a computer;
• and
• a computer-usable medium, the computer-usable medium containing code that, when executed by the computer, causes the computer to,
• receive, at a building, an identification code from a mobile telephone,
• determine that the identification code is valid,
• as a result of the determining, transmit a description of an optical code to the mobile telephone,
• read the optical code from a screen of the mobile telephone, the mobile telephone being borne by a visitor, and
• based on the reading of the optical code, grant to the visitor access to an elevator.

An elevator installation comprising:

• an elevator;
• an access node;
• a control unit coupled to the access node;
• and
• an elevator controller coupled to the control unit and to the elevator, the control unit being configured to,
• receive an identification code from a mobile telephone through the access node,
• determine that the identification code is valid,
• as a result of the determining, transmit a description of an optical code to the mobile telephone through the access node,
• read the optical code from a screen of the mobile telephone, the mobile telephone being borne by a visitor, and
• based on the reading of the optical code, cause the elevator controller to grant to the visitor access to the elevator.

A computer-usable medium containing code that, when executed by a computer, causes the computer to perform a method, the method comprising:

• receiving, at a building, an identification code from a mobile telephone;
• determining that the identification code is valid;
• as a result of the determining, transmitting a description of an optical code to the mobile telephone;
• reading the optical code from a screen of the mobile telephone, the mobile telephone being borne by a visitor;
• and
• based on the reading of the optical code, granting to the visitor access to an elevator.

An elevator access method comprising:

• receiving a request from a building occupant or assistant to generate a user profile for a visitor to a building;
• generating the user profile;
• sending, to a mobile telephone of the visitor, an identification code for the user profile;
• receiving, from the mobile telephone, a request for an access code based on the identification code;
• based on the request for the access code, sending the access code to the mobile telephone, the access code comprising a two-dimensional optical code;
• reading the two-dimensional optical code from a display of the mobile telephone;
• determining that the access code is valid;
• granting to the visitor access to an elevator at the building;
• and
• informing a visited person at the building that the visitor is at the building.