Abstract: Provided are a method, an Internet of Things (IoT) device, and a base station apparatus for subscriber authentication without using a SIM card or a USIM card in a IoT/IosT service based on a 3GPP mobile communication system. The method of authenticating a subscriber of an Internet of Things (IoT) device based on mobile communication includes authenticating the subscriber using a measurement value which becomes a unique characteristic of the IoT device, in which the authenticating of the subscriber is performed using a measurement value which becomes a unique characteristic of the IoT device without using a SIM (subscriber identity module) card or a USIM (universal subscriber identity module) card.

Abstract: MAC (Media Access Control) for an EPON (Ethernet Passive Optical Network system) defined in an IEEE (Institute of Electrical and Electronics Engineers) 802.3ah EFM (Ethernet in the First Mile) standard is implemented using general MAC based on an IEEE 802.3 standard. LLID (Logical Link ID) information is inserted at a predetermined position of a frame outside its preamble and the frame containing the LLID information is transferred to a higher layer so that general MAC can be used as MAC for the EPON system. A physical layer of the EPON system contains LLID information within a preamble and transfers the preamble containing the LLID information. An RS (Reconciliation Sublayer) configures a new Ethernet frame by inserting the LLID information at a predetermined position of the Ethernet frame outside the preamble. The RS transfers the new Ethernet frame to a higher data link layer of the EPON system. The data link layer transfers the new Ethernet frame containing the LLID information.

Abstract: Disclosed is a upstream data transmission method in a gigabit Ethernet-passive optical network (GE-PON) system. In the GE-PON system including an optical line termination having a scheduler and optical network units connected to the optical line termination, the optical line termination receives bandwidth allocation request signals from the optical network units at a start of a first cycle, allocates transmission bandwidths to the respective optical network units in accordance with the bandwidth allocation request signals, and transmits the allocated transmission bandwidths to the respective optical network units before a second cycle that follows the first cycle.

Abstract: A bottom level detection device is disclosed for a burst mode optical receiver. The receiver includes a converter for converting a burst mode signal into a voltage signal and an automatic gain controller for automatically controlling a gain of the converter. The bottom level detection device detects a bottom level of an output signal from the converter and controls the automatic gain controller on the basis of the detected bottom level. The bottom level detection device includes an amplification circuit for receiving the output signal from the converter at its first input terminal and a fed-back output signal from the device at its second input terminal, respectively, and amplifying a difference between the received signals, a detector for detecting a bottom level of an output signal from the amplification circuit, and an output buffer.

Abstract: A GE-PON (Gigabit Ethernet-Passive Optical Network) system is provided that configures upstream and downstream frames on the basis of a variable-length Ethernet frame. The GE-PON system employs TDM (Time Division Multiplexing) for upstream packet transmission in a tree structure for a point-to-multipoint connection. A structure of a frame format is also provided that is capable of effectively accommodating Gigabit Ethernet traffic in the GE-PON system and a method is provided for implementing various functions such as initial ONU registration, late ONU registration, ranging, and dynamic bandwidth allocation in the GE-PON system.

Abstract: An idle pattern output-control circuit used in a point-to-multipoint communication based Gigabit Ethernet-passive optical network (GE-PON) is provided. In a GE-PON having an optical-line terminal (OLT), a plurality of optical-network units (ONUs) connected to each other via an optical-distribution network (ODN), a media-access controller (MAC), and a physical-coding sublayer (PCS), in which the PCS transmits idle-pattern data to a serializer/deserializer (SERDES) when there is no data to be transmitted to the OLT, an idle-pattern output-control circuit comprising a data converter for converting an idle-pattern data generated from the PCS into a low-level optical signal for subsequent transmission to the OLT, and a switching circuit for selecting data generated from the PCS for subsequent transmission to the SERDES when there is data to be transmitted and for selecting data converted by the data converter for subsequent transmission to the SERDES when there is no data to be transmitted.

Abstract: A burst mode optical receiver is disclosed and includes a converter for converting a burst mode signal into a voltage signal, a bottom level detector for detecting a bottom level of an output signal from the converter, an automatic gain controller for automatically controlling the gain of the converter on the basis of the bottom level detected by the bottom level detector in order to maintain an amplitude of the output signal from the converter and generating a reset signal when the bottom level is lower than a predetermined reference value, and a power level detector for detecting a power level of the output signal from the converter and generating the reset signal and an LOS signal indicative of the presence of no input signal when the detected power level is lower than a predetermined reference value.

Abstract: A burst-mode optical receiver of a differential-output structure is disclosed.

Abstract: In an optical receiver having a pre-amplifier for converting a current signal outputted from an optical detector to a voltage signal, a signal level detecting device is provided to provide an LOS (loss of signal) signal and a reset signal from the output of the pre-amplifier. The signal level detecting device comprising: a capacitor for receiving the output from the pre-amplifier; first and second transistors each consisting of an emitter and a collector connected to the output of the pre-amplifier and a base connected to the collector; a third transistor having a collector connected to the collector of the first transistor and an emitter connected to the collector of the second transistor; and, a common emitter circuit with a pair of resistors connected, respectively, to the emitter and collector of the third transistor and capable of detecting the level of a signal inputted from the collector of the third transistor.

Abstract: A peak detector for detecting a peak value of a burst signal in a burst mode optical receiver is disclosed, which comprises: an amplifying terminal configured to reduce an offset of a peak value in a received burst signal using feedback in the peak detector; a transistor that functions as a diode when a positive signal is received from the amplifying terminal; a peak hold capacitor for charging a peak value when the transistor received the positive signal; a signal amplitude detector to monitor the received burst signal amplitude; and a current source to drive a current responsive to the output signal amplitude detector.

Abstract: Disclosed is a node structure of an upgradeable wavelength division multiplexing system that can minimize the expense in implementing, maintaining, and upgrading the system. The node structure includes an interleaver for interleaving a plurality of optical signals received therein into a predetermined number of channels; at least one demultiplexer coupled to one of the output channels for demultiplexing the optical signals received thereto into a prescribed number of channels; at least one multiplexer for multiplexing the respective demultiplexed optical signals from the demultiplexer; and, a deinterleaver for deinterleaving the optical signals outputted from the multiplexer to be forwarded to the next node.

Abstract: The present invention is directed to a bidirectional add/drop multiplexer connected with waveguides at opposite ends thereof, respectively, and adapted to add/drop a channel in forward and reverse directions.

Abstract: A system and method for managing link status in Gigabit Ethernet passive optical network (GE-PON) units (ONUs) is disclosed. The GE-PON comprises one or more ONUs allocated data transmission periods, respectively. Each of the ONUs sends a report signal and a data signal in a corresponding one of the allocated data transmission periods. The report signal contains a signal to request allocation of a bandwidth for data signal transmission in a next window period. The GE-PON further comprises an optical splitter having its one side connected with the ONUs and its other side connected with at least one optical communication channel. The optical splitter switches an input signal to a desired destination.

Abstract: An automatic-gain-control device in an optical receiver is provided and includes a pre-amplifier for converting a current signal outputted from an optical detector to a voltage signal and a bottom level detector for detecting the bottom level from the output of the pre-amplifier, the automatic-gain-control device comprising a bottom signal-level-determining section for analyzing the bottom level from the bottom level detector and outputting a signal denoting the presence of a signal and a reset signal for initialization at intervals between packets; and an automatic-gain-control signal generating section for providing an automatic-gain-control signal by showing the presence of a signal, the automatic-gain-control-signal-generating section including a first transistor which turns on according to a signal from the bottom signal-level-determining section and a second transistor which is connected to a capacitor for charging or discharging a voltage applied by the first transistor, and the drain voltage of which

Abstract: An automatic threshold control device for a burst mode optical receiver is disclosed. The receiver includes a converter that converts a burst mode signal into a voltage signal and an automatic gain controller for automatically controlling a gain of the converter, independently generating a reset signal and applying it to the automatic threshold control device. The automatic threshold control device is adapted to detect a voltage level of an output signal from the converter.

Abstract: A peak detector for detecting a peak value of a burst signal in a burst mode optical receiver is disclosed, which comprises: an amplifying terminal configured to reduce an offset of a peak value in a received burst signal using feedback in the peak detector; a transistor that functions as a diode when a positive signal is received from the amplifying terminal; a peak hold capacitor for charging a peak value when the transistor received the positive signal; a signal amplitude detector to monitor the received burst signal amplitude; and a current source to drive a current responsive to the output signal amplitude detector.

Abstract: An automatic gain control (AGC) apparatus with a short settling time in a burst mode optical receiver is disclosed. The AGC apparatus includes a variable gain amplifier for variably amplifying an input signal according to an AGC adjustment control signal; a clipper coupled to an output terminal of the variable gain amplifier for comparing an output signal of the variable gain amplifier with a preset signal Vcut and for outputting a signal corresponding to the difference between these two signals if the output signal of the variable gain amplifier is higher than or equal to the preset signal Vcut in amplitude; an exponential amplifier for exponentially amplifying an output signal of the clipper; and a peak holder for detecting a peak value from an output signal of the exponential amplifier and for generating the AGC adjustment control signal for controlling a gain of the variable gain amplifier.

Abstract: MAC (Media Access Control) for an EPON (Ethernet Passive Optical Network system) defined in an IEEE (Institute of Electrical and Electronics Engineers) 802.3ah EFM (Ethernet in the First Mile) standard is implemented using general MAC based on an IEEE 802.3 standard. LLID (Logical Link ID) information is inserted at a predetermined position of a frame outside its preamble and the frame containing the LLID information is transferred to a higher layer so that general MAC can be used as MAC for the EPON system. A physical layer of the EPON system contains LLID information within a preamble and transfers the preamble containing the LLID information. An RS (Reconciliation Sublayer) configures a new Ethernet frame by inserting the LLID information at a predetermined position of the Ethernet frame outside the preamble. The RS transfers the new Ethernet frame to a higher data link layer of the EPON system. The data link layer transfers the new Ethernet frame containing the LLID information.

Abstract: A bottom level detection device is disclosed for a burst mode optical receiver. The receiver includes a converter for converting a burst mode signal into a voltage signal and an automatic gain controller for automatically controlling a gain of the converter. The bottom level detection device detects a bottom level of an output signal from the converter and controls the automatic gain controller on the basis of the detected bottom level. The bottom level detection device includes an amplification circuit for receiving the output signal from the converter at its first input terminal and a fed-back output signal from the device at its second input terminal, respectively, and amplifying a difference between the received signals, a detector for detecting a bottom level of an output signal from the amplification circuit, and an output buffer.

Abstract: An automatic-gain-control device in an optical receiver is provided and includes a pre-amplifier for converting a current signal outputted from an optical detector to a voltage signal and a bottom level detector for detecting the bottom level from the output of the pre-amplifier, the automatic-gain-control device comprising a bottom signal-level-determining section for analyzing the bottom level from the bottom level detector and outputting a signal denoting the presence of a signal and a reset signal for initialization at intervals between packets; and an automatic-gain-control signal generating section for providing an automatic-gain-control signal by showing the presence of a signal, the automatic-gain-control-signal-generating section including a first transistor which turns on according to a signal from the bottom signal-level-determining section and a second transistor which is connected to a capacitor for charging or discharging a voltage applied by the first transistor, and the drain voltage of which