Self-clocking scheme for bit synchronisation in ultrafast packet switching transparent optical networks

A challenging issue in ultrafast packet switching transparent optical networks is fast acquisition of synchronisation at the bit level for packet demultiplexing. In the Letter a novel scheme is proposed, in which a timing reference is transmitted along with each data packet in the form of a clock comb. This comb is extracted at each node reached by the packet for header recognition and, at the destination, for reading of that particular packet. The synchronisation problem is solved with no need for a phase locked loop, at the expense of an increased effective packet length.