An embedded wireless system was developed which used a combined Radio Frequency (RF) transceiver and ultrasound sensor to determine the three dimensional location of a person or device within an enclosed space. This study used modified embedded Cricket motes from MIT operating with the Tiny Operating System (OS). Measurements of directivity corresponded strongly with the data provided by the devicesÃÂ¿ manufacturer. A modification to the motes software (Tiny OS) allowed the deployment of Trilateration to measure the three dimensional location of the tracked devices. The trilateration calculation was done on the hybrid Cricket mote and transmitted this data to the listener mote connected to a computer. A visual interface was developed using MATLAB for displaying the location of the tracked object in real time.