Physical access to secure areas is automatically performed based on presence or detection of a wireless device. When a wireless cellular device is detected by a network serving a secure building, a unique identifier of the wireless cellular device is obtained. The identifier of the wireless cellular device may be compared to electronic calendars. If a matching calendar entry is determined, then the wireless cellular device is calendared to meet an employee or tenant inside the building. Physical access may thus be automatically granted, based on possession of a recognized cellular device.