A method includes communicating first and second signals between a first node and a second node, where the first signal includes a sonic signal and the second signal includes an electromagnetic signal. The method also includes using the electromagnetic signal to one of start or stop a timer and using the sonic signal to another of stop or start the timer. The method further includes identifying a one-way time-of-flight associated with the sonic signal traveling between the first and second nodes using the timer. The one-way time-of-flight associated with the sonic signal is indicative of a distance between the nodes.