Abstract: Disclosed is an optical amplifier which includes an upward optical amplifier configured to amplify an input upward optical signal of an input optical signal; and a control circuit configured to control an operation of the upward optical amplifier according to whether an upward stream is detected from the input upward optical signal.

Abstract: A method of transmitting an Operations, Administration and Maintenance (OAM) message and of processing an error in a Passive Optical Network (PON) system is provided. Using an OAM packet format that may be used in common in the PON system, a process of transmitting or receiving an OAM message may be simplified, an efficiency of the process may be increased, and an Optical Network Unit (ONU) may be managed at a high speed.

Abstract: Disclosed is a low power optical network terminal (ONT) and a method of operating the low power ONT. The low power ONT may include a network media access control (MAC) processing unit to transmit and receive traffic to and from an optical line terminal (OLT), a switching unit to receive the traffic transmitted from the network MAC processing unit and transmit the traffic to a subscriber terminal and to receive the traffic from the subscriber terminal and transmit the traffic to the OLT, and a control unit to control traffic transmission from the network MAC processing unit when a power mode is a low power mode.

Abstract: An apparatus and method for managing a dynamic bandwidth allocation to support a low-power mode, in a passive optical network (PON) are provided. The apparatus may include a power saving mode managing unit to manage a power saving mode of at least one optical network unit (ONU), a bandwidth allocation parameter storage unit to store a bandwidth allocation parameter used for a power saving mode, and to maintain the stored bandwidth allocation parameter, and a dynamic bandwidth allocating unit to provide bandwidth allocation information to the at least one ONU, when the stored bandwidth allocation parameter is received.

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: According to a method of reducing power in an optical access network, upon the application of power, an optical network terminal (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 optical line terminal (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. If the requirements are satisfied, the ONT transmits a wake-up signal to the OLT and switches to the activation mode for normal operation.

Abstract: Provided is an apparatus for filtering a multicast port identifier, the apparatus including: a processor to receive an Internet Group Management Protocol (IGMP) message from a switching unit, to verify a traffic reception request received from a subscriber terminal based on the IGMP message, and to store a value in a filtering register based on the traffic reception request; and an Optical Network Unit (ONU) Media Access Control (MAC) manager to filter a packet to be forwarded to the subscriber terminal, using a port identifier for traffic forwarding and reception with the subscriber terminal, and using the value of the filtering register indicating an existence of traffic to be forwarded to the subscriber terminal.

Abstract: A Passive Optical Network (PON)-based system and method for providing handover between Optical Network Terminals (ONTs) are provided. The PON-based system may include an Optical Line Terminal (OLT), and an ONT to relay communication between the OLT and a mobile terminal. When the mobile terminal is connected to the ONT, the ONT may transmit a WiFi location update alarm message to the OLT, and the OLT may update a Look-Up Table (LUT) in response to the WiFi location update alarm message.

Abstract: Disclosed herein are a remote node and a telephone station terminal in a passive optical network (PON). The remote node includes an optical circulator that transmits downlink signals input from a downlink optical backbone network to a wavelength distributor and transmits uplink signals input from the wavelength distributor to an uplink optical backbone network different from a downlink optical backbone network; and a wavelength distributor that distributes the downlink signal input from the optical circulator into a plurality of wavelengths to be connected to an optical distribution network and connects the uplink signals input from the optical distribution network to the optical circulator.

Abstract: Disclosed is an optical amplifier which includes an upward optical amplifier configured to amplify an input upward optical signal of an input optical signal; and a control circuit configured to control an operation of the upward optical amplifier according to whether an upward stream is detected from the input upward optical signal.

Abstract: Provided is an optical network unit saving power. The optical network unit may include a processor checking whether at least one downward physical block, the upward physical block and a data switching block operate in an idle mode, sequentially transiting at least one downward physical block, an upward physical block and a data switching block to a sleep mode according to the checking result and sequentially transiting an optical transmission-reception block and the medium access control block to a sleep mode by judging whether or not a medium access control block transits to a sleep mode.

Abstract: A method of transmitting an Operations, Administration and Maintenance (OAM) message and of processing an error in a Passive Optical Network (PON) system is provided. Using an OAM packet format that may be used in common in the PON system, a process of transmitting or receiving an OAM message may be simplified, an efficiency of the process may be increased, and an Optical Network Unit (ONU) may be managed at a high speed.

Abstract: Disclosed is an optical line terminal device which includes a media access control (MAC) block configured to convert Ethernet packets and port identifiers into a downstream frame or an upstream frame into the Ethernet packets and the port identifiers; and a central processing unit (CPU) configured to control the MAC block, wherein the MAC block includes a traffic monitoring part which is configured to receive the port identifiers and to provide identifier information of an optical network device according to the port identifiers; and wherein the CPU is configured to generate a control frame for controlling a power supplied to the optical network device, according to identifier information of the optical network device.

Abstract: A method and apparatus of detecting a rogue optical network unit (ONU) is provided. An optical line terminal (OLT) detects an abnormal upstream transmission to determine a plurality of rogue ONU candidates, and transmits a sleep allow message instructing a transition to a sleep mode to each of the plurality of rogue ONU candidates. The OLT detects the rogue ONU among the plurality of rogue ONU candidates based on upstream transmissions from the plurality of rogue ONU candidates in the sleep mode. Since the detection of the rogue ONU is performed in the sleep mode, the remaining ONUs can transition from the sleep mode to the normal mode after the detection of the rogue ONU is completed, thereby making it possible to rapidly resume upstream communication.

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 is an optical line terminator (OLT) to recover packet data and a clock from an optical signal including a silent interval. The OLT may receive packet data and a clock from at least one optical network unit (ONU). Even in a silent interval in which the at least one ONU does not transmit packet data, the OLT may successfully recover the clock.

Abstract: An optical subscriber network for power reduction is provided. The optical subscriber network may include an Optical Line Terminal (OLT) and an Optical Network Terminal (ONT). The OLT may manage a plurality of ONTs by classifying the plurality of ONTs into a sleep group, and may multicast a sleep allowance message only to ONTs included in a predetermined sleep group.

Abstract: A dynamic bandwidth allocation apparatus of a passive optical network detects guarantee agreement information of each transmission container (T-CONT) queue of at least one optical network unit (ONU) that is connected to the dynamic bandwidth allocation apparatus in order to dynamically allocate a bandwidth is provided. The dynamic bandwidth allocation apparatus sets a queue threshold according to a buffer size of each T-CONT queue of at least one ONU, and calculates a service level agreement (SLA) parameter of at least one ONU using guarantee agreement information and a queue threshold. The dynamic bandwidth allocation apparatus allocates a bandwidth for every frame of each ONU using each SLA parameter of at least one ONU.

Abstract: Provided is an apparatus for filtering a multicast port identifier, the apparatus including: a processor to receive an Internet Group Management Protocol (IGMP) message from a switching unit, to verify a traffic reception request received from a subscriber terminal based on the IGMP message, and to store a value in a filtering register based on the traffic reception request; and an Optical Network Unit (ONU) Media Access Control (MAC) manager to filter a packet to be forwarded to the subscriber terminal, using a port identifier for traffic forwarding and reception with the subscriber terminal, and using the value of the filtering register indicating an existence of traffic to be forwarded to the subscriber terminal.

Abstract: Provided is a method of controlling a server to simultaneously update software installed in a plurality of terminals in a communication system, the method including: receiving an update message from each of the terminals; determining a size of a transmission window based on the update message; processing an image of software to be transmitted to the plurality of terminals, based on the size of the transmission window; and transmitting the image of software to the plurality of terminals.