Abstract: The present invention discloses a multiple star wavelength division multiplexing passive optical network system using a wavelength assignment method. In a multiple star wavelength division multiplexing passive optical network system using a wavelength assignment method according to the present invention, only one WDM-PON system can provides services for a plurality of subscribers who is distributed in a wide range of area through multiple starring, by setting one or more band for transmitting up-stream signals as an up-stream basic band and one or more band for transmitting down-stream signals as a down-stream basic band, respectively, and by dividing each of the up-stream basic band and the down-stream basic band into a plurality of wavelength sub-bands and assigning the divided sub-bands to different areas using a wavelength division multiplexer/de-multiplexer which splits a band into two or more sub-bands.

Abstract: An Arrayed Waveguide Grating Router (AWGR) for wavelength multiplexing and demultiplexing is provided. According to an aspect, by generating phase differences of a plurality of received optical signals through an arrayed wavelength in which a plurality of waveguides having a predetermined length difference with respect to each other are arranged, and then coupling the optical signals with the different phase differences, wavelength multiplexing and wavelength demultiplexing are simultaneously performed using the maximum constructive interference and/or destructive interference effect of optical signals.

Abstract: The present invention discloses a wavelength-division multiplexing passive optical network (WDM-PON) capable of high-bandwidth transmission for optical signals by using modulation format having high spectral efficiency. The WDM-PON according to the present invention provides a larger capacity and higher bandwidth transmission economically (at lower costs) by using a modulation format where spectral efficiency (a transmission bit number per a unit band width) is high, while using a low noise part of a light source.

Abstract: A link setup method for a wavelength-division-multiplexing passive optical network (WDM PON) system. The system includes a service providing device, a local node, and a plurality of subscriber devices. The link setup method includes assigning an initial wavelength for communication between the service providing device and a new subscriber device to be installed in the local node. The assigning of the initial wavelength may be performed as a part of process for activating the subscriber device, and this procedure may be performed between a physical layer of the service providing device and a physical layer of the new subscriber device.

Abstract: Provided are an automatic wavelength recognition apparatus and method. The automatic wavelength recognition apparatus includes: a division unit receiving a single optical signal and dividing the received optical signal into a plurality of optical signals; a plurality of filter units filtering the optical signals and having different and wavelength-dependent pass characteristics; a plurality of detection units detecting the filtered optical signals and measuring intensities of the detected optical signals; at least one comparison unit comparing outputs of any two of the detection units; and a wavelength determination unit receiving an output of the at least one comparison unit and determining a wavelength of the above single optical signal using a pre-stored look-up table.

Abstract: The present invention discloses a transmission device of a low-noise optical signal having a low-noise multi-wavelength light source, a transmission device of broadcast signals using a low-noise multi-wavelength light source, and an optical access network having the same. The present invention uses a low-noise multi-wavelength light source (LMLS) which has sufficiently low noises at respective wavelengths, while being lasing at a multi-wavelength. Noises at respective wavelengths are not increased, even though an output light of such an LMLS passes through a wavelength division multiplexer/demultiplexer (a tunable optical filter or an arrayed waveguide grating (AWG), etc.). When using an LMLS, it is possible to embody an optical access network capable of transmitting optical signals at a high-speed and simultaneously transmitting a multicast signal. Further, when embodying an optical amplifier by using a gain medium for an LMLS, it is possible to obtain gain at a broad band without cross-coupling.

Abstract: The present invention discloses a multiple star wavelength division multiplexing passive optical network system using a wavelength assignment method. In a multiple star wavelength division multiplexing passive optical network system using a wavelength assignment method according to the present invention, only one WDM-PON system can provides services for a plurality of subscribers who is distributed in a wide range of area through multiple starring, by setting one or more band for transmitting up-stream signals as an up-stream basic band and one or more band for transmitting down-stream signals as a down-stream basic band, respectively, and by dividing each of the up-stream basic band and the down-stream basic band into a plurality of wavelength sub-bands and assigning the divided sub-bands to different areas using a wavelength division multiplexer/de-multiplexer which splits a band into two or more sub-bands.

Abstract: A data transmission apparatus for use in a separate-type base station is provided. The data transmission apparatus includes: a digital unit configured to generate first data that includes transmission method information indicating a selected transmission method and data to be transmitted; a time-division synchronization control unit configured to, in response to the selected transmission method being time-division multiplexing (TDM), generate second data by including synchronization information for transmitting the first data using TDM in the first data; and a wavelength conversion unit configured to convert at least one of the first data and the second data into one or more wavelength optical signals using a predefined wavelength or a predefined group of wavelengths and transmit the wavelength optical signals to one or more radio stations.

Abstract: The present invention relates to a wavelength-division multiplexed passive optical network (WDM-PON) for reducing degradation in noise characteristic of a wavelength-locked Fabry-Perot Laser Diode (F-P LD).

Abstract: An optical source for wavelength division multiplexed optical network according to the present invention comprises a broadband light source (BLS); an arrayed waveguide grating (AWG) for spectrum-dividing incoherent light outputted from the BLS; a circulator being connected between the BLS and the AWG; and a plurality of un-polarized light sources (UPLS) being respectively connected to the AWG, wherein the incoherent light which is spectrum-divided by the AWG is injected into the plurality of UPLS and thus the plurality of UPLS is wavelength-locked thereto. In case of using an optical source for wavelength division multiplexed optical network and a wavelength division multiplexed-passive optical network having the same according to the present invention. It is especially possible to lower dramatically the power of incoherent light being injected into a wavelength-locked Fabry-Perot laser diode, while to enable a high transmission speed of 1.

Abstract: The present invention discloses a wavelength-division multiplexing passive optical network (WDM-PON) capable of high-bandwidth transmission for optical signals by using modulation format having high spectral efficiency. The WDM-PON according to the present invention provides a larger capacity and higher bandwidth transmission economically (at lower costs) by using a modulation format where spectral efficiency (a transmission bit number per a unit band width) is high, while using a low noise part of a light source.

Abstract: The present invention discloses a wavelength-division multiplexing passive optical network (WDM-PON) capable of high-bandwidth transmission for optical signals by using modulation format having high spectral efficiency. The WDM-PON according to the present invention provides a larger capacity and higher bandwidth transmission economically (at lower costs) by using a modulation format where spectral efficiency (a transmission bit number per a unit band width) is high, while using a low noise part of a light source.

Abstract: The present invention discloses a fault localization method and a fault localization apparatus in a Passive Optical Network (PON) and a passive optical network having the same. A fault localization method in PON according to the present invention comprises a) configuring an optical path of a remote node (RN) selectively by electric power being fed temporarily only when necessary, while the PON is regularly being operated as a passive network; and b) detecting a fault occurring on the selectively configured optical path by inserting a monitoring signal of an OTDR unit, which is positioned in a central office (CO), through the selectively configured optical path.

Abstract: The disclosure relates to an optical receiver having an apparatus for varying decision threshold level and an optical transmission system having the same. An optical receiver having an apparatus for varying decision threshold level includes a photo diode (PD) for receiving an optical signal and transforming the received optical signal into an electrical signal; a trans-impedance amplifier (TIA) for pre-amplifying the electrical signal transformed by the PD; a limiting amplifier (LA) for deciding the electrical signal amplified by the TIA as either level 0 or level 1 and for amplifying the decision signal; a clock and data recovery (CDR) for generating a clock and data from the amplified decision signal by the LA; and a control circuit for adjusting a decision threshold level depending on the received optical signal power by the PD and for providing the adjusted decision threshold level with the LA.

Abstract: The present invention discloses a remote node (RN) configuration for providing an enhanced service in a passive optical network and a passive optical network (PON) having the same. In an RN configuration for providing a new service in a PON according to the present invention, it is possible to configure the RN remotely by instantaneous powering from a remote site only when necessary, while the RN being operated as a PON at ordinary times. More specifically, an RN configuration for providing a new service in a PON according to the present invention includes a power generation block capable of providing energy necessary for activating the RN by instantaneously supplied power from the remote site.

Abstract: The present invention relates to a wavelength-division multiplexed passive optical network (WDM-PON) for reducing degradation in noise characteristic of a wavelength-locked Fabry-Perot Laser Diode (F-P LD).

Abstract: The present invention discloses a network architecture for upgrading a legacy time division multiplexing-passive optical network (TDM-PON) to a wavelength division multiplexing-passive optical network (WDM-PON) based next-generation passive optical network (next-generation PON), wherein the legacy TDM-PON comprises: a central office (CO) having a first optical line termination (OLT); a remote node (RN) having a splitter; a single mode fiber (SMF) connecting the first OLT and the splitter; and a first group of one or more optical network terminations (ONTs) being connected to the splitter by a first group of one or more distribution fibers, and wherein the network architecture further comprises: in case that the next-generation PON is a WDM-PON, a first apparatus for combining and splitting wavelength bands being positioned between the SMF and the first OLT, in order to add a second OLT to be used for the WDM-PON within the CO or within another CO which is located in a position different from the CO, while sha

Abstract: The present invention discloses a network architecture for upgrading a legacy time division multiplexing-passive optical network (TDM-PON) to a wavelength division multiplexing-passive optical network (WDM-PON) based next-generation passive optical network (next-generation PON), wherein the legacy TDM-PON comprises: a central office (CO) having a first optical line termination (OLT); a remote node (RN) having a splitter; a single mode fiber (SMF) connecting the first OLT and the splitter; and a first group of one or more optical network terminations (ONTs) being connected to the splitter by a first group of one or more distribution fibers, and wherein the network architecture further comprises: in case that the next-generation PON is a WDM-PON, a first apparatus for combining and splitting wavelength bands being positioned between the SMF and the first OLT, in order to add a second OLT to be used for the WDM-PON within the CO or within another CO which is located in a position different from the CO, while sha

Abstract: The present invention discloses a multiple star wavelength division multiplexing passive optical network system using a wavelength assignment method. In a multiple star wavelength division multiplexing passive optical network system using a wavelength assignment method according to the present invention, only one WDM-PON system can provide services for a plurality of subscribers who is distributed in a wide range of area through multiple starring, by setting one or more band for transmitting up-stream signals as an up-stream basic band and one or more band for transmitting down-stream signals as a down stream basic band, respectively, and by dividing each of the up-stream basic band and the down stream basic band into a plurality of wavelength sub-bands and assigning the divided sub-bands to different areas using a wavelength division multiplexer/de-multiplexer which splits a band into two or more sub-bands.

Abstract: The present invention relates to a long-reach wavelength division multiplexing passive optical network(WDM-PON), and especially to the long-reach WDM-PON capable of ensuring economic and stable QoS (Quality of Service). The Long-reach WDM-PON in accordance with the present invention includes an optical transmitter/receiver located at central office and each optical network termination; wavelength division multiplexer/demultiplexer located at said central office and remote node; and broadband incoherent light source which is connected with a long-reach single-mode fiber to said wavelength division multiplexer/demultiplexer and spectrum-sliced and injected into the transmitters located at said central office and each optical network termination.