Detecting the location of a phone using RF wireless and ultrasonic signals

A apparatus for determining a presence of a mobile device located in a predetermined detection zone within a vehicle, the apparatus comprising:

• the mobile device, comprising:
• a wireless signal receiver configured to receive one or more radio frequency (RF) signals;
• an acoustic receiver configured to receive a plurality of sounds comprising an acoustic environment;
• a processor configured to receive:
• acoustic data from the acoustic receiver, wherein the acoustic data corresponds to the plurality of sounds comprising the acoustic environment;
• and
• a wireless synchronization signal from the wireless signal receiver;
• a non-transitory memory in data communication with the processor, wherein the non-transitory memory stores instructions that, when executed by the processor, causes the processor to:
• receive the wireless synchronization signal;
• record the acoustic data upon receiving the wireless synchronization signal;
• determine that the periodically recorded acoustic data comprise a periodically recorded first acoustic signal comprising a first ultrasonic pulse and a second acoustic signal comprising a second ultrasonic pulse;
• calculate a first time of arrival of the first acoustic signal and a second time of arrival of the second acoustic signal;
• determine a location of the mobile device within the vehicle based on the first time of arrival and the second time of arrival;
• determine that the location of the mobile device matches the predetermined detection zone;
• determine that the periodically recorded acoustic data comprise a periodically recorded first acoustic signal comprising a first ultrasonic pulse having a frequency in the range of 15 kHz to 60 kHz;
• and
• determine that the periodically recorded acoustic data comprise a periodically recorded second acoustic signal comprising a second ultrasonic pulse having a frequency in the range 15 kHz to 60 kHz.