Firstly, this clock can be used as a local time clock.

The local clock is in communication with a certified master clock.

Each data value is stored for a predetermined number of periods of a local clock.

The data is received from the bus by receive logic employing a local clock.

At the receiver (2) the data is detected in phase with a local clock.

A local clock (78) determines the rate at which signals of the radio sources are sampled.

Data is clocked from the buffer (106) by a local clock (114).

The terrestrial transmitter (7) is assumed to have a known position and the local time is measured relative to a clock local to the mobile device (2).

In one approach, a local clock is used for timing when the recovered clock is not available.

A local clock network (10, 12) has a reference control unit (16a, 16b) having a reference clock, processing unit and data memory.

Both stations emit signals (S1 and S2) in coherence with their respective local clocks.

The local clock period is updated on an ongoing manner by downstream known received traffic.

A method is disclosed of synchronizing at least temporarily, a local clock such as a clock included in an RFID tag, to an external time varying signal.

The method includes receiving (S1100) time information from a local clock (320/340), a reference clock (110, 310/330/350), and one or more secondary clocks (120).

The second phase-locked circuit is configured for taking the intermediate clock and a local clock fed by a local oscillator as input, and outputting a second output clock.