A remote communication system (20) includes a signaling device (24)
and a remotely located controller (26). The signaling device (24)
includes a synchronization counter (44) and the controller includes a synchronization
counter (34). Under normal circumstances, a transmitter (42) sends
signals that are received by a receiver (32) and then processed appropriately
by the controller (26). Transmissions from the transmitter (42) to
the receiver (32) preferably are encrypted and then deciphered based upon
a value from the synchronization counters. When the synchronization counter values
do not correspond sufficiently to allow effective communication, synchronization
counter value information is shared using a bi-directional communication link (50,
52) so that there may be correspondence between the synchronization counter
values. In one example, low frequency (LF) signals are used for transmitting the
synchronization counter values across the bi-directional communication link.