Patent ID: 9160519
Filing Date: 2015-10-13
Classification: H04J,H04L,H04W

Abstract:
1. A method for communicating between a local device having a first clock, a low-frequency (LF) transmitter and a high-frequency (HF) transceiver, and a remote device having a second clock, an LF receiver and an HF transceiver, the method comprising: transmitting an LF signal from the local device to the remote device; at the remote device, synchronizing the second clock based on the LF signal, and transmitting a first HF signal to the local device using the synchronized second clock and a first predetermined time delay relative to receipt of the LF signal at the remote device; at the local device, synchronizing the first clock based on the first HF signal, and transmitting a second HF signal to the remote device using the first clock and a second predetermined time delay relative to receipt of the first HF signal at the local device; and at the remote device, re-synchronizing the second clock based on the second HF signal and while accounting for a trip time for at least one of communicating the first HF signal from the remote device to the local device, and communicating the second HF signal from the local device to the remote device.