A startup protocol is provided for use in a communications system having a
plurality of transceivers, one transceiver acting as a master and another
transceiver acting as slave, each transceiver having a noise reduction
system, a timing recovery system and at least one equalizer. The
operation of the startup protocol is partitioned into three stages.
During the first stage the timing recovery system and the equalizer of
the slave are trained and the noise reduction system of the master is
trained. During the second stage the timing recovery system of the master
is trained in both frequency and phase, the equalizer of the master is
trained and the noise reduction system of the slave is trained. During
the third stage the noise reduction system of the master is retrained,
the timing recovery system of the master is retrained in phase and the
timing recovery system of the slave is retrained in both frequency and
phase. The protocol then enters a fourth stage in which the master
transceiver and the slave transceiver are ready to communicate with each
other.