Patent attributes
Aspects of the present disclosure provide communications between local and remote devices having low-frequency (LF) and high-frequency (HF) circuits. As may be implemented in accordance with one or more embodiments, the local device transmits an LF signal to the remote device, which synchronizes its clock based on the LF signal. Another LF signal is communicated from the local device to the remote device using a reduced quality factor, which can be implemented to facilitate synchronization. The clock is resynchronized based on the second LF signal and used to transmit an HF signal with a time delay. The local device synchronizes its clock based on the HF signal, and transmits another HF signal to the remote device using the clock and another time delay. The remote device re-synchronizes its clock based on the second HF signal while accounting for a trip time for communicating the first and/or second HF signals.