Abstract:
본 발명은 수동형 광 가입자 네트워크의 대역폭 할당 방법은 파장분할방식을 기반으로 파장을 가변시켜 하향 데이터를 전송하고, 시간분할방식을 적용하여 상향데이터가 전송되도록 하여 네트워크 대역폭의 효율적인 할당을 통한 데이터 전송이 가능하고 통계적 다중화를 실현하여 전송효율이 향상되는 효과가 있다. 수동 광 가입자망, PON, ONT, OLT, 대역폭, 하이브리드
Abstract:
PURPOSE: A planar lightwave circuit, a wavelength tunable light source and a WDM-PON(Wavelength Division Multiplexing-Passive Optical Network) using the light source are provided to secure mechanical stability of a thin film metal heater by stacking a heat block layer between a lower clad layer and a silicon substrate. CONSTITUTION: A wavelength tunable light source of a PLC external cavity laser includes a first housing, a second housing, and a third housing. A semiconductor light gain medium(400) is mounted in the first housing. A PLC element is mounted on the second housing. The optical fiber(600) is mounted in the third housing. The first to third housings are arranged in an optical axis through a light coupling lens. The first to third housings are coupled through a laser welding method.
Abstract:
본 발명은 루프백방식의 파장분할다중방식 수동형 광가입자 시스템에 관한 것으로, 하향 신호들을 하향 광 SCM 신호들로 변환한 후 파장다중화하여 전송하거나, 파장다중화된 상향 광 OOK 신호를 파장역다중화, 수신 및 복조하여 상향 신호들로 변환하는 중앙기지국; 상기 파장다중화된 하향 광 SCM 신호를 수신하여 상기 하향 광 SCM 신호들로 파장역다중화한 후 전송하거나, 상향 광 OOK 신호들을 수신하여 파장다중화한 후 전송하는 지역기지국; 및 상기 하향 광 SCM 신호들을 제1 및 제2 광 SCM 신호들로 분기한 후, 상기 제1 광 SCM 신호들은 상기 하향 신호들로 변환하고, 상기 제2 광 SCM 신호들을 이용하여 상기 상향 신호들을 상기 광 OOK 신호들로 변조하여 상기 지역기지국로 전송하는 가입자 접속 장치들을 포함하여 구성되며, 이에 의하여 항상 안정적인 전송 품질을 보장하면서도 시스템 구축 비용을 감소시킬 수 있도록 한다. WDM-PON, SCM, ROSA
Abstract:
An optical subscriber network system applying a wavelength division multiplexing technique to a TDM(Time Division Multiplexing)-PON(Passive Optical Network) and a service providing method are provided to enlarge a transmission distance between a central office and a terminal of a subscriber and to reduce a feeder optical filer line by applying WDM(Wavelength Division Multiplexing) transmission method between the central office and a remote node. An optical signal outputted from a wavelength multiplexing part(210) of an RN(Remote Node)(200) to a subscriber's device(300) is inputted to an optical circulation part(220). The optical signal circulates in the optical circulation part and is outputted to an optical amplifier(330) of the subscriber's device. The optical signal inputted to the optical amplifier of the subscriber's device is amplified and is inputted to the optical circulation part. The optical signal inputted to the optical circulation part is circulated and is outputted through an optical splitter(230). The optical splitter of the RN outputs the inputted optical signal to ONU(Optical Network Unit)s of M. Optical signals outputted from ONUs of M are merged in the optical splitter of the RN and is inputted to the optical circulation part of the RN. The optical signal inputted to the optical circulation part is circulated and is outputted to a wavelength converter(320) of the subscriber's device(300). The optical signal inputted to the wavelength converter is converted to the designated optical wavelength and inputted to the optical circulation part. The optical signal re-inputted to the optical circulation part is circulated and is outputted to the designated port of the wavelength multiplexing part.
Abstract:
An apparatus and a method for recovering a carrier in a baseband receiver of a QAM(Quadrature Amplitude Modulation) system of a high order are provided to maintain a capturing time uniformly although a carrier frequency offset increases by operating a carrier recovering device having a wide frequency recovering range and a fast capturing time. An apparatus for recovering a carrier in a baseband receiver of a QAM(Quadrature Amplitude Modulation) system of a high order includes a phase detection unit(250), a polarity detection unit(230), a frequency detection unit(240), and a fixed signal detection unit(260). The phase detection unit detects a phase offset of a baseband signal of which a phase is changed. The base band signal is received to a carrier recovering device. The polarity detection unit detects a polarity of a selected symbol used for recovering the carrier. The polarity detection unit detects a phase offset of the selected symbol based on the polarity. The frequency detection unit detects the frequency offset based on an output of the polarity detection unit. The fixed signal detection unit detects whether the phase offset and the frequency offset of the carrier are removed below a predetermined reference value. The fixed signal detection unit switches one of the output of the phase detection unit, the output of the polarity detection unit, and the output of the frequency detection unit to be used for capturing the carrier.
Abstract:
An evolutionary WDM/TDM hybrid PON apparatus is provided to expand capacitance and improve the quality of a service by using an RN of a WS-PS structure and ONT of RSOA method and by using a T-LD as a seed light source. An optical circuit terminal comprises a T-LD(Tunable laser diodes)(201) transmitting a downstream signal, a wavelength coupler(202) which multiplexes the wavelength and downloads it, and an optical receiver(203,204) of an expansion type wavelength distribution structure, which provides the connection for an upper level switch port and expands and distributes the multiplexed wavelengths outputted from the wavelength coupler. A remote node(207) comprises a wavelength distribution coupler(209) which distributes an input wavelength, and a power distribution coupler(208) which distributes the input power. A plurality of ONTs(Optical Network Terminal) of the RSOA way transmit upstream data by modulating again the upstream signals to the incoming downstream signals.
Abstract:
A PLC(Planar Lightwave Circuit) device, a wavelength tunable light source comprising the same, and a WDM-PON(Wavelength Division Multiplexing-Passive Optical Network) using the light source are provided to secure mechanical stability of a thin film metal heater by laminating a heat shielding layer between a lower clad layer and a silicon substrate. A PLC device includes a silicon substrate(110), a heat shielding layer(113), a thin film metal heater(103), and an optical waveguide. The heat shielding layer is formed on the silicon substrate in order to shield thermally the silicon substrate from an upper layer of the substrate. The thin film metal heater is formed on the heat shielding layer. The optical waveguide includes a clad layer and a core layer formed on the thin film metal heater by using a polymer. A Bragg grating(102) is formed on the core layer corresponding to an upper part of the thin film metal heater.
Abstract:
A control apparatus and a control method by a software are provided to supply various new premium services to users and to have the compatibility to the existing digital broadcasting. A control part(210) controls a target device according to a stored control program and a control parameter. A conversion part(220) converts the two wire series-type external signal for correcting the control program and adjusting the control parameter from an external host into the inner signal for setting or investigating the state values of the input-output pins for connecting each inner circuit of the target device. An inner interface part(230) approaches directly the inner circuit according to the command included in the converted inner signal, and sets and investigates the state values of the input-output pins. The target device is an optical transceiver. The control program performs a digital diagnostic monitoring control function defined in the SFF(Small Form Factor)-8472 standard.
Abstract:
본 발명은 ONT의 광파장 구분을 제거하기 위하여 종래 제안된 광파장 재활용 방식으로 관리를 최적화할 수 있는 반사형 반도체 광증폭기(Reflective Semiconductor Optical Amplifier: RSOA)를 활용하는 WDM-PON 구조에서, OLT 광원들의 광파장 구분을 제거하기 위하여 씨드 광 주입(seed-light-injected) 형태로 RSOA를 OLT에 활용하는 방안을 제시한다. 본 발명에 의해서 ONT의 광파장 구분은 광파장 재활용 방식의 RSOA에 의해서 제거되고 OLT의 광파장 구분은 씨드 광 주입 방식의 RSOA에 의해서 제거되는 WDM-PON이 구현될 수 있다.
Abstract:
본 발명은 RSOA에 입력되는 광 파워를 검출할 수 있는 장치를 포함한 RSOA를 이용한 광송수신 모듈, 그 모듈을 포함한 PON 및 그 모듈의 입력 광파워 검출방법을 제공한다. 그 광송수신 모듈은 중앙 기지국(Central Office:CO) 및 가입자단(Optical Network Terminal:ONT)을 포함하는 수동형 광가입자망(Passive Optical Networks:PON)에 있어서, PON의 중앙 기지국으로부터 하향 신호를 수신하는 수신기; 하향 신호를 받아 상향 신호로 재변조하여 전송하는 루프-백(loop-back) 방식의 반사형 반도체 광증폭기(Reflective Semiconductor Optical Amplifier:RSOA); 및 RSOA에 입력되는 상기 하향 신호의 광파워를 검출하는 광파워 검출장치;를 포함하고 상기 ONT의 광송수신 모듈로 이용된다.