Patent ID: 8274426

Claim:
A ranging system for determining a ranging measurement, the ranging system comprising: a first unit that transmits at least one signal on at least one carrier asking for the ranging measurement, the at least one signal including at least one read range data packet; a second unit that receives the at least one signal, wherein the second unit achieves commonality of frequency and phase coherence with the at least one signal, the second unit including: a first oscillator used in receiving the at least one signal and transmitting at least one second signal back to the second unit; a reference oscillator that controls the first oscillator, wherein the at least one read range data packet is used to achieve the commonality of frequency and phase coherence in the reference oscillator; and a phase coherency counter, wherein the phase coherency counter enables the second unit to transmit the at least one second signal back to the first unit with a predictable phase; and wherein the first unit receives the at least one second signal and determines the ranging measurement between the first unit and the second unit.