Patent ID: 8326146

Claim:
A communications node for routing an optical signal comprising at least one data packet from a first data flow, the node comprising: an input optic link and an output optic link in communication with each other; an optical correlator; an optical input switch; an optical to electrical converter; a transmitter; an optical splitter, the input optic link being in communication with the optical splitter, the optical splitter being arranged to split an incoming optical signal into at least two substantially identical optical signals, the optical splitter further arranged to pass one of the optical signals to the optical correlator and the other of the optical signals to the input optical switch; the optical correlator being arranged to compare an address of the packet with a reference address and to generate a trigger signal if the reference address matches the address of the packet; the input optical switch being arranged to route the data packet to the optical to electrical converter in response to the trigger signal to drop the data packet from the node; an input delay line between the optical splitter and the input switch; an output optical switch receiving an input from the transmitter and the input optical switch, the output optical switch having an output to the output optical link; the transmitter being adjusted to add a data packet to the node; the transmitter being arranged to transmit an optical packet to the output optical switch in response to the trigger signal from the optical correlator; and a control node in communication with the input optic link and arranged to add a dummy packet, and wherein upon detecting the dummy packet the optical correlator is arranged to cause the transmitter to fill a payload of the dummy packet with the payload of a data packet added to the node.