Abstract: Provided is a multi-ring network operating method of cross-connecting at least two ring networks, the method including connecting an input working ring and an input protection ring of a ring network to an output working ring and an output protection ring of another ring network and then performing cross-connection between the same or different ring networks by using a multi-dimensional cross-connect apparatus. In the multi-ring operating method, a plurality of ring networks can be connected regardless of the protection method used by the ring networks, and the original protection method of each ring network can remain after they are connected.

Abstract: In a conventional network for transmitting an optical burst signal, it is impossible to effectively swap labels, reproduce a payload signal, and switch and transmit the signals.

Abstract: Provided is an optical network node device. According to the optical network node device, a planar lightwave circuit (PLC) based or a blocker based 4-terminals ROADM can be used in a node of at least degree 3, a proceeding direction of a wavelength channel can be changed in an electrical cross connect switch, and transmission in a unit smaller than a wavelength channel can be cross connected, dropped, and added, or transmission capacity can be redistributed in the electrical cross connect switch. Accordingly, efficient transmission in a small capacity and large capacity transmission of a wavelength channel can be performed simultaneously, and thus an optical network can be effectively managed. Also, since the node of at least degree 3 uses the PLC based or a blocker based reconfigurable optical add drop multiplexer (ROADM), the node of at least degree 3 can use the same ROADM module as a node of degree 2. Accordingly, the optical network node device has an advantage in manufacturing and managing a node.

Abstract: An optical node capable of supporting a mesh-type optical network is provided.

Abstract: Provided are an apparatus and a method for reducing a signal noise of an OCDMA receiver and an OCDMA receiver and method. The includes: a clock recovery unit extracting sine wave clock from an output signal of an OCDMA decoder including an MAI (multiple access interference) noise; a time gating unit separating an auto-correlation peak signal and the MAI noise from the output signal of the OCDMA decoder using the sine wave clock; and an optical interferometer removing an SI (signal interference) noise remaining in the auto-correlation peak signal.

Abstract: Provided are a photonic cross-connector system, a wavelength division multiplexing (WDM) system using the photonic cross-connector system, and an optical communication network based on the WDM system. The photonic cross-connector system includes: an optical coupler branching an input optical signal into a plurality of paths; a wavelength selective switch (WSS) extracting at least one wavelength signal from the input optical signal and outputting the extracted wavelength signal to at least one port; a WDM multi-casting apparatus simultaneously copying and reproducing the input optical signal into different wavelengths and changing modulation methods of the input optical signal into different types of modulation methods; an optical transmitter and/or receiver branching and coupling the input optical signal; and a control system controlling the optical coupler, the WSS, the WDM multicasting apparatus, and the optical transmitter and/or receiver.

Abstract: Disclosed herein is a wavelength-division-multiplexed metro optical network. The network comprises a transmitting unit having direct modulating transmitters and a multiplexer for multiplexing the optical signals and transmitting the multiplexed signal, and a receiving unit having a demultiplexer for receiving the multiplexed signal from the multiplexer, demultiplexing the received signal and outputting the demutiplexed signals, and receivers for receiving the demutiplexed signals. The network further comprises an optical fiber connected between the multiplexer and the demultiplexer. The optical fiber has a negative dispersion value of from −1 ps/nm/km to −3.3 ps/nm/km at a wavelength of 1550 nm, and a positive dispersion inclination.