Abstract: In the manufacture and application of a PLC-ECL type wavelength tunable light source, provided is a wavelength tunable mechanism with improved performance and stability, a light source with improved packaging performance and mass productivity, and a light source applied to a WDM-PON with initialization and stabilization functions. The wavelength tunable light source having a PLC (planar lightwave circuit)-ECL (external cavity laser) structure includes a first housing in which a semiconductor optical gain medium is mounted, a second housing in which a PLC device is mounted, and a third housing in which an optical fiber is mounted. The first, second, and third housings make an optical axis alignment through an optical coupling lens and combined in a laser welding method.

Abstract: An all-optical carrier sense multiple access collision detection apparatus and method for checking by using mutual gain saturation whether distortion occurs in two or more optical signals due to mutual interference when the optical signals pass through a semiconductor optical amplifier.

Abstract: The present provides a method of dynamically managing multicast groups and allocating multicast service wavelengths for the highest channel efficiency. According to the present invention, the share indices of wavelengths of all multicast service groups, which employ broadcasting wavelengths and data wavelengths, are periodically ascertained on the basis of IGMP snooping-based technology in a WDM-PON. Based on the ascertainment results, if the channel share index of the group that employs the broadcasting wavelength is smaller than the channel share index of the group that employs the data wavelength, the share index of the wavelength of the multicast group that employs the broadcasting wavelength is maximized by dynamically changing allocation of the wavelength of the multicast group, so that a maximum multicast service can be provided within limited resources.

Abstract: The present invention provides an apparatus and method for preserving a frame sequence and distributing traffic in a multi-channel link, which efficiently distributes frame traffic while preserving the transmission sequence of frames in a link composed of multiple channels, and to a multi-channel transmitter using the apparatus and method. The present invention determines whether the preservation of a sequence of frames is required using information about received frames, predicts a frame transmission service finish time on the basis of the length of frames if the sequence preservation is required, determines a sequence preservation service time (SPST) on the basis of the predicted transmission service finish time, stores the frames in a sequence preservation buffer for the SPST, and distributes the frames to idle transmitters at a termination point of the SPST, thus maximizing the efficiency of channel use.

Abstract: The invention relates to an Ethernet-based all-optical carrier sense multiple access/collision detection apparatus and method, and more particularly, to an apparatus and method capable of checking by using mutual gain saturation whether distortion occurs in two or more optical signals due to mutual interference when the optical signals pass through a semiconductor optical amplifier (SOA) at the same time, amplifying the optical signals transmitted in the upward direction when no distortion occurs in the optical signals, and monitoring the occupation of a plurality of subscribers with respect to a common network when the plurality of subscribers want to use an optical Ethernet network.

Abstract: A termination device for use in a WDM-SCM PON system can effectively support a multi-channel integration function of a WDM/SCM PON system.

Abstract: Provided is an apparatus that enables improvement of efficiency of up/downstream packet tensception by reflecting a plurality of variables of packet transmission, such as a temporal variety of packet lengths, asymmetry of downstream and upstream traffics, and an instantaneous burst of a traffic amount, on a loop-back-based WDM-PON.

Abstract: A termination device for use in a WDM-SCM PON system can effectively support a multi-channel integration function of a WDM/SCM PON system.