Patent ID: 8521091

Claim:
A method of measuring a distance between two radiocommunication devices, comprising the following steps: a—by a first radiocommunication device of the two radiocommunication devices: transmitting a radio signal requesting a measurement of an exchange delay between the two devices; b—by a second radiocommunication device of the two radiocommunication devices: receiving the request signal; and sending an acknowledgement radio signal after an intermediate delay known to both the first and the second devices; c—by the first device: receiving the acknowledgement signal; measuring the time between transmitting the request signal and receiving the acknowledgement signal; storing said measured time as the exchange delay; and calculating a first time of flight of the request signal and of the acknowledgement signal based on the exchange delay and the intermediate delay; and d—by the second device: transmitting a single channel measurement frame configured so that the first device: determines, from various radio signals received corresponding to the single channel measurement frame, a difference in time of flight between a propagation path corresponding to said first time of flight and the shortest propagation path followed by the radio signals transmitted between the two devices; and calculates a second time of flight from the first time of flight and the difference in time of flight.