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: The present invention provides a device and method for allocating a bandwidth to a plurality of optical network units (ONUs) for transmitting an uplink frame in the EPON. The bandwidth allocation device includes a plurality of optical network units and an optical line terminal (OLT). The optical network units classify uplink data to be transmitted to an optical line terminal according to a predetermined priority, and transmit the classified uplink data by receiving an allocated bandwidth according to each class from the optical line terminal. The optical line terminal preferentially distributes a predetermined bandwidth for transmitting uplink frames of a highest priority class to the optical network units and then dynamically distributes a remained bandwidth form transmitting the uplink frames for remained classes.

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: The present invention relates to a media access controller, and more particularly, to a media access controller which can adjust operational parameters according to a setting environment of a packet transmission system by re-setting the operational parameters of the media access controller by an external source.

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: An Internet protocol (IP)-based integrated customized broadcast service system and method are provided. The IP-based integrated customized broadcast service system includes: a subscriber schedule table providing server generating a subscriber schedule table matching with a time when a user desires to be provided with a broadcast program or IP-based content; and a broadcast server transmitting the broadcast program to the user who desires to be provided with the broadcast program or converting the IP-based content to a broadcast service format that can be watched by the user and transmitting the converted IP-based content to the user who desires to be provided with the IP-based content according to the subscriber schedule table. Accordingly, video on demand (VoD) content, user created content (UCC), and proteur created content (PCC) can be used for broadcasting, so that a variety of broadcast programs can be configured.

Abstract: An optical communication system and method using Manchester encoded signal remodulation are provided. The optical communication system includes a transmitter generating and transmitting a Manchester encoded optical signal including a first data stream, and a receiver receiving an optical signal obtained by dividing power of the Manchester encoded optical signal into two parts and modulating one of the two parts to include a second data stream, and recovering the second data stream. In two-way communication, the optical communication system and method allow one party to generate and transmit a Manchester encoded signal (i.e., a downstream signal) to the other party and allow the other party to generate an upstream signal by modulating the optical power of the downstream signal without using a light source.

Abstract: Provided is a method of transmitting and receiving a two-way advertisement. The method is performed separately from a broadcasting being received by a client. When the client calls for the two-way advertisement, an Internet Protocol (IP)-based two-way advertisement receiving apparatus of the client requests and receives the two-way advertisement from an IP-based two-way advertisement server; stores the two-way advertisement in an advertisement storage unit, wherein the two-way advertisement is transmitted from the IP-based two-way advertisement server which refers to an advertisement area code included in the two-way advertisement and transmits the two-way advertisement by using a multicast group address corresponding to the advertisement area code; and displays the two-way advertisement on a screen of a client using terminal of the client.

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 an apparatus and method for managing customized channels in Internet Protocol (IP)-based broadcasting services.

Abstract: There is provided a user device for providing customized contents, including: a data receiving unit for receiving user multimedia data from outside; an authoring information setting unit for setting user authoring information on the user multimedia data upon a user's request; a data encoding unit for encoding the user multimedia data and the user authoring information to generate contents data; a data transmission unit for transmitting the generated contents data to a customized contents authoring device through a network; a data receiving unit for receiving authorized data transmitted from the customized contents authoring device; and a data output unit for extracting the customized contents data from the received customized data and outputting the extracted contents data.

Abstract: A personal-ordered multimedia data search service method and apparatuses thereof are provided.

Abstract: Provided is a method of monitoring link performance and diagnosing an active link state without interrupting traffic in an Ethernet passive optical network (EPON) while the link is in the active state.

Abstract: Provided are a combined, fixed codebook searching method and apparatus used in a code excited linear prediction (CELP) speech codec.

Abstract: Provided are a clock signal selecting apparatus and method that can guarantee the continuity of an output clock signal. The clock signal selecting apparatus and method can synchronize the phases of at least two clock signals by continuously controlling the phases of the clock signals. Accordingly, even when an active clock signal and a standby clock signal have different frequencies, it is possible to guarantee the continuity of the output clock signal regardless of whether the clock signals are switched from one to another. In addition, it is possible to guarantee the stability of the output clock signal.

Abstract: An Internet broadcasting system and a method thereof are provided.

Abstract: A system and method for providing an interactive multimedia service to a user in an access network are provided. The system includes a multimedia service providing server and a user terminal. The multimedia service providing server creates multimedia information requested by a user terminal, processes the created multimedia information, and manages a corresponding communication channel to allow a predetermined user terminal to receive the processed multimedia information. The user terminal transmits inputted user multimedia information to the multimedia service providing server through the access network and receives the multimedia information transmitted from the multimedia service providing server through the access network.

Abstract: The invention relates to an EPON bridge apparatus and a forwarding method thereof. In case of receiving frame from the network port or the PON port, the apparatus associates the port having the received frame inputted with source MAC address of the received frame to learn the information in an FDB table which manages port information for the learned MAC address. Then the apparatus refers to the FDB table to remove LLID from upstream frame, and then forwards the upstream frame to the network port, while attaching LLID corresponding to destination MAC address to downstream frame to transmit to the PON port. Bridging between ONUs are possible with flooding capability using anti-LLID. It provides VLAN-LLID translation mode with support for VLAN tag addition/removal at the ONU side. It also provides multicast pruning function for the downstream.

Abstract: A method and apparatus for duplex protection switching by using a single splitter in a passive optical network (PON) are provided. The apparatus for duplex protection switching in a PON, in which a single optical line termination (OLT) and many optical network terminations (ONTs) are connected together in a multiple-access manner, includes: a 2:2 splitter connected to two PON line terminations (LTs) in the OLT; and two N:1 splitters which are connected to the 2:2 splitter, and each of which is connected to two PON LTs in the ONT. According to the method and apparatus, an economical effect can be provided in which two links, an operational link and a protection link, in the PON can provide a partial duplex function at a lower cost. Also, a protection switching time can be reduced by simplifying a restoration process so that when an error is detected, an operational state is returned by protection switching.