A method and system for determining a minimum time of flight between
communication devices is useful for correcting ranging errors induced by
multi-path signals. The method includes transmitting a range request
message, including a first periodically repeating synchronization
sequence, from the first communication device via a first RF channel to
the second communication device (step 91). A range response message,
including a second periodically repeating synchronization sequence and a
minimum path turn around time, is then received at the first
communication device via a second RF channel from the second
communication device (step 92). A change in the second RF channel is
induced after receipt of each synchronization sequence. A minimum path
round trip time is then determined from multiple time of arrival
determinations (step 93). Finally, the minimum time of flight is
calculated from the minimum path round trip time and the minimum path
turn around time (step 94).