Abstract: Provided is a TDMA (time division multiple access) PON (passive optical network) OLT (optical line terminal) system for a broadcast service, including packet processor determining information according to types of frames (unicast, multicast, and broadcast frames) and a switch output port using header information (an IP address of a packet header, MAC (medium access control) addresses of Ethernet frames, and the like) of data received from an external node or the ONT (optical network terminal) and attaching the information to header parts of the frames to generate second data, a switch copying the second data by a predetermined number of times according to a transmission method and transmitting the second data to a corresponding destination output port according to the identification codes, M TDMA PON MAC processors removing the identification codes added to the second data and converting the second data into TDMA PON frames, and M optical transceivers converting the TDMA PON frames into optical signals and tr

Abstract: Provided is a method of reducing power consumption of an optical access network (OAN) as much as possible by configuring an optical line terminal (OLT) and optical network terminals (ONTs) in the OAN to support a maximum power-saving mode. According to the method, upon the application of power, an ONT operates normally in an activation mode. The ONT then determines whether the requirements for switching from activation mode to power-saving mode are satisfied. If the requirements are satisfied, the ONT transmits a sleep signal to an OLT, which is a message notifying that the ONT will soon switch to power-saving mode. Thereafter, the ONT switches to power-saving mode and cuts off power for all functions except for power for monitoring and controlling external inputs. The ONT then determines whether the requirements for switching from power-saving mode to activation mode are satisfied.

Abstract: Provided are a hybrid optical transceiver module having an optical amplifier packaged thereto for outputting a high-power optical signal to remove problems regarding narrow emission angle and optical alignment, and a passive optical network (PON) system having an improved optical network terminal (ONT) accommodation capability using the hybrid optical transceiver module. The hybrid optical transceiver module includes a first package in which an LD (laser diode) is packaged, and a second package in which SOA (semiconductor optical amplifier) and a PD (photo diode) are packaged. The first and second packages are coupled to be one package so as to output a high-power optical signal.

Abstract: Provided are an apparatus and method for efficiently and dynamically allocating a bandwidth on a Time Division Multiple Access-based Passive Optical Network (TDMA PON).

Abstract: Provided is a TDMA (time division multiple access) PON (passive optical network) OLT (optical line terminal) system for a broadcast service, including packet processor determining information according to types of frames (unicast, multicast, and broadcast frames) and a switch output port using header information (an IP address of a packet header, MAC (medium access control) addresses of Ethernet frames, and the like) of data received from an external node or the ONT (optical network terminal) and attaching the information to header parts of the frames to generate second data, a switch copying the second data by a predetermined number of times according to a transmission method and transmitting the second data to a corresponding destination output port according to the identification codes, M TDMA PON MAC processors removing the identification codes added to the second data and converting the second data into TDMA PON frames, and M optical transceivers converting the TDMA PON frames into optical signals and tr

Abstract: Disclosed are an optical line terminal in a gigabit passive optical network and a method for transmitting a broadcast frame using the same. The optical line terminal allocates second port identifiers to optical network units such that a broadcast frame is prevented from being retransmitted to an optical network unit which has transmitted the broadcast frame to the optical line terminal.

Abstract: A burst mode optical repeater is provided. The burst mode optical repeater receives optical signals, which are transmitted from a plurality of optical network units (ONUs) in a passive optical network (PON) to a central office using a time division multiplexing access (TDMA) method, and relays the received optical signals using an optical-electrical-optical (OEO) method. Since the burst mode optical repeater can be installed anywhere between an optical line terminal (OLT) and the ONUs, the number of subscribers and transmission range that can be supported by a corresponding network can be increased.

Abstract: A dynamic bandwidth allocation (DBA) device and a method thereof are provided. In the DBA method, the band allocation periods according to class queues and allocable bands with respect to each class queue are calculated on the basis of the service level agreement information and stored according to the service types in separate tables. The bandwidth allocation amount is calculated with respect to class queues which have the allocation periods by concurrently checking all the tables at each frame. The upward bandwidth usage efficiency is improved by calculating the final bandwidth allocation information from the service with a high priority order on the basis of the total allocable bandwidth of the corresponding frame. The upward bandwidth allocation amount can be calculated at each frame by reducing the processing speed in calculating the bandwidth allocation amount of each class queue. Accordingly, it is possible to effectively use the network.

Abstract: Provided is an automatic optical power control method for an optical line terminal (OLT) of a passive optical network (PON). The automatic optical power control method includes at the OLT, measuring an allowable range of the optical power allowing a normal network operation on the PON, at the OLT, setting an optimum optical signal level within the measured allowable range of the optical power, and at the OLT, adjusting a power level of a transmitter to the set optimum optical signal level. Accordingly, an appropriate power level can be selected depending on an optical distribution network (ODN) structure to drive the transmitter. Also, when the entire optical network units are deactivated, a laser of the transmitter is turned off to thereby minimize unnecessary power consumption at the OLT.

Abstract: Provided are a laser diode which has low power consumption and can realize a high on/off extinction ratio by small variation of current and which can modulate optical signals at high speed, an optical transmitter, and an optical communication apparatus including the optical transmitter. The laser diode having an abrupt turn-on characteristic, comprises: an active region in which light is generated by application of current and gain is controlled; and an absorption region absorbing light generated in the laser diode at a current lower than an abrupt threshold current that is the same as or lower than an operation current, the operation current being a current level that allows the laser diode to generate a target optical power, wherein the output optical power rapidly increases at the abrupt threshold current.

Abstract: A passive optical network system includes: a plurality of optical signal splitter receiving optical signals from a plurality of optical network units (ONUs) to provide a plurality of upstream optical signals having different wavelengths; a hybrid optical filter multiplexing the plurality of upstream optical signals in a wavelength division multiplexing (WDM) scheme; and an optical line terminal (OLT) receiving the multiplexed upstream optical signals in a time division multiplexing (TDM) scheme. Therefore, the network system can be easily expanded when the number of subscribers increases, and the optical loss can be minimized.

Abstract: Provided are an optical output power control method that provides optical communication without harming the human body even when a transmission line is cut or no optical network unit (ONU) accesses a communication system, and a passive optical network (PON) system using the method. In the method, an optical signal having a predetermined period is transmitted when an optical communication system is in an abnormal state, wherein the predetermined period includes a laser-on time interval in which the optical signal has a normal power level and a laser-off time interval in which the optical signal is off or has a power level lower than the normal power level, so that the optical communication system performs optical communication without harming the human body even during the abnormal state.

Abstract: Provided are a sing-unit integrated transceiver having a pump source and a transceiver module using the transceiver.

Abstract: Provided is an optical filtering apparatus which is applied to a Time Division Multiplexing Passive Optical Network (TDM-PON) based on a wavelength division multiplexing (WDM) method. The optical filtering apparatus includes: an optical signal distributing unit dividing an optical signal received from an optical line terminal into at least one optical signal with uniform output intensity, and distributing the at least one optical signal into at least one optical network unit; and a multiplexing unit combining a plurality of optical signals having different wavelengths received from the at least one optical network unit using a wavelength division multiplexing (WDM) method, and outputting the combined optical signal to the optical line terminal. Therefore, by using the optical filtering apparatus, it is possible to connect a large number of subscribers to an Optical Line Terminal (OLT) on a network such as Fiber To The Home (FTTH), thereby increasing efficiency in costs.

Abstract: Provided is a time division multiplex (TDM)/wavelength division multiple access (WDMA) passive optical network (PON) device. The TDM/WDMA PON device comprises a base station terminal, a wavelength splitter, and a subscriber terminal optical transceiver. The base station terminal comprises a transmitter time-division-multiplexing and simultaneously modulating and outputting a plurality of different wavelength optical signals, an optical circulator transmitting the optical signals output from the transmitter to an optical distribution network and transmitting optical signals received from the optical distribution network to a receiver and the receiver demultiplexing wavelength division multiplexed upstream signals from the optical distribution network through the optical circulator, converting the demultiplexed upstream signals into a plurality of electrical signals, and delivering the electrical signals to an upper layer.

Abstract: Provided are high power PLC optical Tx module and PLC optical Tx/Rx module. The PLC optical Tx/Rx module is located in an OLT of a PON system. The high power PLC optical Tx/Rx module includes a photodiode, a laser diode, an SOA, an optical coupler, and a PLC platform. The photodiode converts an input optical signal into an electrical signal, and the laser diode generates an optical signal of a predetermined wavelength. The SOA amplifies the optical signal generated by the laser diode, and the optical coupler couples optical signals, outputs the coupled signal to a splitter, divides an optical signal from the slitter, and outputs the divided signals to the photodiode. The PLC platform incorporates the photodiode, the laser diode, the SOA, and the optical coupler into one package to allow an optical signal to be output with high power.

Abstract: A pluggable optical transceiver module is provided. The pluggable optical transceiver module is fitted to and removed from a receptacle having a clamp at an end in an optical communication system body and includes a housing frame having an adaptor at which a light emitting diode (LED) display unit and an optical transceiver element are installed; a rotary lever comprising a handle at one side and a pressing portion at another side so that the rotary lever rotates by a predetermined angle with respect to one side of the housing frame; and an elastic arm which is pivoted on the housing frame to be rotated by the rotary lever and includes one end contacting the pressing portion according to rotation of the rotary lever and another end coupled with or separated from the clamp of the receptacle by the rotation.

Abstract: Provided are a hybrid optical transceiver module having an optical amplifier packaged thereto for outputting a high-power optical signal to remove problems regarding narrow emission angle and optical alignment, and a passive optical network (PON) system having an improved optical network terminal (ONT) accommodation capability using the hybrid optical transceiver module. The hybrid optical transceiver module includes a first package in which an LD (laser diode) is packaged, and a second package in which SOA (semiconductor optical amplifier) and a PD (photo diode) are packaged. The first and second packages are coupled to be one package so as to output a high-power optical signal.

Abstract: Disclosed are an optical module interfacing device for connecting an RJ interface and an SFP type optical module to an SFP type optical module connector without additional processing, and an Ethernet system using the optical module interfacing device, thus supporting data transmission and reception. The optical module interfacing device includes a board having the same dimensions as those of the optical module, a male connector, having the same dimensions as those of the optical module, formed at a side surface of one end of the board to be connected to the female connector for the optical module mounted on a host board, and an RJ female connector provided with a plurality of pins formed on an upper surface of the board, respectively corresponding to pins of the male connector, according to standards. Further, UTP data is provided to MDI supporting ports of a physical layer through an interfacing unit.

Abstract: A method for managing a content addressable memory (CAM) look-up table using the longest prefix matching (LPM) is provided. The method includes providing a pair of pointers per every band of data having the same prefix in length, wherein one of the pair of pointers stores the address of data having the lowest address in each band of data, and the other pointer of the pair of pointers stores the next higher address of data having the highest address in each band of data; and making a space in which data is to be added in the CAM look-up table by moving data having the addresses stored in the pair of pointers provided per each band of data that has a shorter prefix length than the prefix length of the data to be added, when data is added to the CAM look-up table. According to the method, it is possible to easily and efficiently add new data into the look-up table of the CAM.