Electronics and Telecommunications Research Institute

Sk Energy Co., Ltd.

Sk Holdings Co., Ltd.

Information and Communications University Educational Foundation

Sang Soo Lee

Kwang Ok Kim

Jie Hyun Lee

Min Soo Kim

Seung Il Myong

Seung-Hyun Cho

Hwan Seok Chung

Je Soo Ko

Jyung Chan Lee

Kyeong Hwan Doo

Eui Suk Jung

Eun Gu Lee

Seung Hyun Cho

Young Ho Kim

Han Hyub Lee

Kwangjoon Kim

Heuk Park

Sun Hyok Chang

Sil Gu Mun

Jong Hyun Lee

Dong Soo Lee

Moo Jung Chu

Han-Hyub Lee

Jin Soo Han

Seong Jun Lee

Hyun Woo Cho

Jong Ho Lim

Dong Cheol Shin

Jae Kyu Jin

Jae Suk Koh

Hong You

Jun Seong Bang

Chan Gyo Han

Weon Jung Choi

Byoung In Lee

Sang Kyu Lim

Man Seop Lee

Jong Wook Kim

Jong Hoon Lee

Seung Kwan Kim

Chang Bong Kim

Chun Young Kim

Bo Hun Choi

Seon Yeong Jeon

Jun Bae Hong

Soon Ki Kwon

Yun Hi Kim

Jong Ho c/o Sk Corporation Lim

Jun Bae Sk Institute Of Technology Hong

Seon Yeong c/o Sk Corporation Jeon

An optical fiber cable of a mobile fronthaul system based on a radio over fiber (RoF), which includes a control apparatus for monitoring an analog optical link according to an exemplary embodiment, may be monitored. The monitoring control apparatus may include an optical signal monitor to monitor an optical signal passing through an optical fiber cable, and a system controller to control the optical signal based on a result of the monitoring. The optical signal monitor may calculate an average optical power, carrier-to-noise ratio (CNR), and a size of a nonlinear component from an electrical signal, which has been acquired from the optical signal. Then, the optical signal monitor may control the calculated average optical power, CNR, and nonlinear component.

Control apparatus and method for monitoring optical fiber link

Provided are an Optical Network Unit (ONU) for low latency packet transmission in a Time Division Multiplexing-Passive Optical Network (TDM-PON), a method of operating the ONU, and an apparatus for controlling the ONU. The method includes: receiving, from a base station, first bandwidth allocation information regarding a bandwidth allocated by the base station to a terminal for uplink packet transmission; and transmitting a bandwidth allocation request, which is based on the received first bandwidth allocation information, to an Optical Line Terminal (OLT) before completing packet reception from the base station.

Optical network unit (ONU) for low latency packet transmission in time division multiplexing-passive optical network (TDM-PON), method of operating the same, and apparatus for controlling ONU

An arrayed waveguide grating device and a method for manufacturing the arrayed waveguide grating device. The arrayed waveguide grating device includes input channel waveguides formed on a substrate; output channel waveguides formed on the substrate that correspond to the input channel waveguides; and arrayed waveguides with different lengths interposed between the input channel waveguides and the output channel waveguides on the substrate while free propagation regions being formed at both ends of the arrayed waveguides, wherein the arrayed waveguides are designed so that a free spectral range (FSR) of a higher-order mode is twice or greater than a bandwidth of a region of interest (ROI).

Arrayed waveguide grating device and method for manufacturing the same

An interface for transmitting a high-speed signal and an optical module including the same. The interface may include a main substrate and a sub-substrate. The main substrate may have at least one high-speed signal line formed on the upper surface of the main substrate. The sub-substrate may have a first conductive line formed on the lower surface thereof so as to adjust high-speed signal transmission characteristics of the high-speed signal line, wherein the first conductive line may be coupled to the upper surface of the main substrate and partially overlap with the high-speed signal line.

Interface for transmitting high-speed signal and optical module including the same

A signal level detector comprising and a Burst-Mode Trans Impedance Amplifier (BM-TIA) using the same. The signal level detector includes a level detector configured to detect peak voltage of an input voltage signal, a reference voltage generator configured to generate second reference voltage by receiving first reference voltage, a comparator configured to compare the peak voltage and the second reference voltage and output a discrimination value according to a comparison result, and a latch configured to store the differential output from the comparator, wherein the level detector and the reference voltage generator have differential amplifier in the same structure.

High speed signal level detector and burst-mode trans impedance amplifier using the same

A burst-mode optical amplification apparatus and method is provided. The burst-mode optical amplification apparatus includes a gain saturation signal generator configured to generate a gain saturation signal for gain stabilization based on an incoming input optical signal; a wavelength multiplexer configured to wavelength multiplex the incoming input optical signal and the gain saturation signal; and an optical amplifier configured to amplify both the wavelength-multiplexed input optical signal and the wavelength-multiplexed gain saturation signal. The apparatus may further include a time delay module configured to synchronize the input optical signal and the gain saturation signal by delaying the transmission time of the input optical signal, taking into consideration the processing time needed by the gain saturation signal generator to generate the gain saturation signal.

Burst-mode optical amplification apparatus and method thereof

A board assembly for transmitting a high-speed signal and a method of manufacturing the same. The board assembly may include a submount board, a base board, and a contact member for a signal line. The submount board may include at least one first high-speed signal line formed on the surface thereof. The base board may include the submount board on one part of the upper surface thereof, and at least second high-speed signal line on the other part of the upper surface thereof, wherein the second high-speed signal lines corresponds to the first high-speed signal lines, respectively. The contact member for the signal line may be installed on the side of the submount board, and have an upper portion contacting the first high-speed signal line and a lower portion contacting the second high-speed signal line such that the first high-speed signal line contacts the second high-speed signal line.

Board assembly for transmitting high-speed signal and method of manufacturing the same

A method of tuning a wavelength in a TWDM-PON which has a plurality of operable channels is provided. First, a second channel is added as an operating channel of the TWDM-PON in which at least a first channel is working, and then an OLT that is providing a service to an ONU through the first channel requests the ONU to tune to the second channel. In response to receiving the request, the ONU determines whether a downstream wavelength of the second channel has been recorded thereon. According to the determination result, the ONU sends to the OLT an ACK message that indicates that the ONU is able to perform wavelength tuning and then commences wavelength tuning to the second channel, or the ONU sends to the OLT a NACK message that indicates that the ONU is unable to perform wavelength tuning.

Method of tuning wavelength in time and wavelength division multiplexing-passive optical network (TWDM-PON)

Provided is a buffer amplifier. The buffer amplifier includes: a replica bias unit dividing an internal power voltage received from an internal power node to generate a bias voltage; an input unit including a first differential amplifier comparing a first differential input signal with the bias voltage to output a first internal signal and a second differential amplifier comparing a second differential input signal with the bias voltage to output a second internal signal; and an output unit including a third differential amplifier comparing the first internal signal with the second internal signal to output a first differential output signal and a second differential output signal.

Buffer amplifier and trans-impedance amplifier including the same

A tunable optical network unit (ONU) for a multi-wavelength passive optical network (MW PON) system and an operation method thereof are provided. The tunable ONU includes a cyclic tunable filter configured to have cyclic wavelength transmission properties that allow all wavelength channels of both a downstream signal and an upstream signal and to vary a wavelength to pass therethrough; a wavelength splitter configured to split an upstream signal wavelength band and a downstream signal wavelength band; a photodetector element configured to detect a downstream signal that is transmitted through the wavelength splitter, passing through the cyclic tunable filter which is aligned to a specific downstream signal wavelength channel; and a tunable transmitter configured to output to the wavelength transmitter an upstream signal of a wavelength channel that is determined based on an aligned downstream signal wavelength channel of the cyclic tunable filter.

Tunable optical network unit for multi-wavelength passive optical network system and operating method thereof

Provided is a hybrid passive optical network (PON) system. The hybrid PON system of wavelength division multiplexing (WDM)/time division multiplexing (TDM) may include an optical line terminal (OLT) and an optical network unit (ONU). The OLT and the ONU may transmit a signal based on wavelength reuse using a seed light source and a reflective modulator. The light source may include a seed light source having a single wavelength, two seed light sources having different wavelength bands, and a light source having a wavelength tunable characteristic.

Hybrid passive optical network system

A converged passive optical network (CPON) and a data transmission method are disclosed. The CPON is a combination of a time division multiple access-passive optical network (TDMA-PON) and an orthogonal frequency division multiple access-passive optical network (OFDMA-PON) and is able to dynamically controlling a bandwidth for upstream signal transmission through allocation of multiple subcarriers to each single optical network unit (ONU).

Converged PON for TDMA-PON service based on OFDMA-PON

A wired/wireless converged media access control (MAC) adaptor and a method for transmitting a frame using the same. The wired/wireless converged MAC adaptor may include a service network interface (SNI) to transmit a MAC frame corresponding to a wired or wireless service, or common public radio interface (CPRI) data, a frame conversion unit to convert, into an orthogonal frequency division multiplexing (OFDM) frame, a wired/wireless converged MAC frame having a common frame structure of the MAC frame corresponding to the wired or wireless service or the CPRI data, and an OFDM interface configured to transmit the OFDM frame to an optical OFDM modem by dynamically allocating sub-carriers based on data transmission characteristics.

Wired/wireless converged MAC adaptor and method of transmitting frame using wired/wireless converged MAC adaptor

A modulation method of an optical modem and a signal transmission apparatus performing the method are disclosed. The modulation method of the optical modem includes an optical interface providing a signal to a light source, a photo detector receiving reflected light by an optical link when output light from the light source based on the provided signal is reflected by the optical link, the photo detector measuring and determining characteristics of the optical link using the reflected light, and the optical modem determining a power level and a modulation method for each subcarrier based on the characteristics of the optical link.

Signal transmission apparatus and optical modem modulation method

A relaying method of an optical signal of a hybrid relaying apparatus in a gigabit passive optical element includes: selecting and receiving any one of a first serial electrical signal corresponding to a downlink wavelength division multiplexing-passive optical line terminal (WDM-PON OLT) optical signal and a second serial electrical signal corresponding to a downlink gigabit passive optical network optical line terminal (GPON OLT) optical signal; modulating the downlink serial electrical signal to a downlink GPON transmission convergence (GTC) frame; extracting control information for uplink transmission from the downlink GTC frame; converting the downlink GTC frame into the downlink serial electrical signal; and converting the converted serial electrical signal into an optical signal and transmitting the converted optical signal in a GPON OLT optical transceiver.

Apparatus and method for relaying in gigabit passive optical network

Growing community of inventors

Daejeon, South Korea

Sang Soo Lee