US Patent 7812709 Office communication system

An office communication system provides intra-office communication within a medical or dental office, for example. The system includes a door or wall unit, a table or desk unit, and a wearable or portable unit. The door and desk units are configured to transmit and receive both infrared and radio frequency type wireless signals. The portable unit may include an infrared light transmitter configured to transmit infrared light encoded with a unique address or identifier. The system operates to non-obtrusively notify office personnel whether a practitioner has entered or is presently within a particular exam room of the office, even if a door of the exam room is closed.