Abstract: Provided is an optical transceiver including a reference tunable laser module configured to generate and output light of a reference wavelength; a first general tunable laser module configured to generate and output light of a first wavelength; and a controller configured to control a tuning operation of the first wavelength of the first general tunable laser module, based on information about a relationship between the reference wavelength and the first wavelength.

Abstract: An analog distributed antenna system having a set of small cells as a signal source is provided. A proposed cellular communication system includes an upper small cell unit including upper protocol processors configured to process an upper first part of a protocol stack of a small cell, a lower small cell unit including lower protocol processors configured to process a remaining second part of the protocol stack of the small cell, and a first matching switch configured to respectively match the lower protocol processors to a plurality of remote units. According to one aspect, the cellular communication system includes a common controller configured to control activation of the plurality of upper protocol processors of the upper small cell unit and the plurality of lower protocol processors of the lower small cell unit according to a required service capacity and appropriately control an operation of the first matching switch.

Abstract: A method of operating a repeater comprises detecting a synchronization signal from a received communication signal, identifying a time division duplex (TDD) switching pattern based on a power change of the communication signal over time and switching an uplink operation and a downlink operation of the repeater based on the detected synchronization signal and the TDD switching pattern.

Abstract: A method of operating a repeater comprises selecting some of adaptive filter coefficients among a plurality of adaptive filter coefficients of an adaptive filter used for interference cancellation, based on the size of a coefficient, generating a predicted interference signal using the selected adaptive filter coefficients and generating an interference-canceled communication signal from a received signal using the generated predicted interference signal.

Abstract: According to one or more embodiments of the present invention, a frame processing method of a distributed antenna system may include confirming whether a quality of service (QoS) tag exists in header information of a received frame; performing frame scheduling of the frame based on the QoS tag; and dropping or transmitting the frame according to a transmission priority according to a result of the frame scheduling.

Abstract: An optical communication device includes: a first multiplexer including a first transmitting port and a second transmitting port; a downstream wavelength analyzer configured to analyze first transmission light to recognize a first downstream wavelength corresponding to the first transmission light and analyze second transmission light to recognize a second downstream wavelength corresponding to the second transmission light; and a controller configured to generate a first control signal for allowing the first transmitting port to pass light corresponding to the first downstream wavelength and allowing the second transmitting port to pass light corresponding to the second downstream wavelength, and output the first control signal to the first multiplexer, wherein the first multiplexer, according to the first control signal, controls the first transmitting port to correspond to the first downstream wavelength and controls the second transmitting port to correspond to the second downstream wavelength.

Abstract: According to an aspect of the disclosure, a mobile communication repeater comprises a receiver configured to receive a plurality of test signals from a plurality of external communication devices and subsequently, receive a plurality of downlink signals from the external communication devices, and a digital signal processor configured to measure a delay time of each of the plurality of test signals, generate a sync time based on the delay times, and delay each of the plurality of downlink signals to correspond with the sync time.

Abstract: According to an aspect of the disclosure, an optical communication module comprises an optical transmission assembly configured to generate first transmit light based on an input electric signal and output the first transmit light, an optical reception assembly configured to divide input first receive light into first receive payload data and first receive auxiliary management data, and an auxiliary management controller configured to analyze the first receive auxiliary management data and control attenuation of one or more of transmit light output from the optical transmission assembly and receive light input to the optical reception assembly, wherein the first receive light is formed by combining the first receive payload data and the first receive auxiliary management data, and the first receive payload data and the first receive auxiliary management data have different wavelengths.

Abstract: Provided are a communication node which comprises a signal monitoring device configured to receive a plurality of communication signals transmitted from two or more base stations, and to monitor a bandwidth of each of the received communication signals, a frame setter configured to reset a frame structure by merging at least some of blocks in a preset frame structure according to a result of the monitoring, and a framer configured to frame the plurality of communication signals into one frame by including the plurality of communication signals in a block corresponding to a bandwidth of each of the plurality of communication signals according to the reset frame structure.

Abstract: Disclosed is an OpenFlow based distributed antenna system (DAS) policy routing method. The DAS policy routing method includes: extracting, by a DAS unit, a match field from header information of a received frame; and comparing, by the DAS unit, the extracted match field with a matching rule of a forwarding table to route according to a matching traffic transmission policy and output a frame to an output port of the DAS unit.

Abstract: Provided is an optical transceiver including: an optical transmitter configured to sequentially generate a plurality of optical transmission signals each including transmission wavelength information and output the plurality of optical transmission signals to a connected multiplexer/demultiplexer; and a controller configured to generate the transmission wavelength information for each of the plurality of optical transmission signals.

Abstract: A method of operating a repeater comprises detecting a synchronization signal from a received communication signal, identifying a time division duplex (TDD) switching pattern based on a power change of the communication signal over time and switching an uplink operation and a downlink operation of the repeater based on the detected synchronization signal and the TDD switching pattern.

Abstract: There is provided a method of processing uplink Ethernet packets of an aggregation node included in a distributed antenna system, the method includes: receiving a plurality of uplink Ethernet packets; summing the plurality of received uplink Ethernet packets; and transmitting the summed uplink Ethernet packets in an uplink direction.

Abstract: Provided is an optical communication device including: a multiplexer configured to multiplex one or more input optical signals to output a single first optical signal; a signal generator configured to generate a second optical signal having a preset wavelength; a filter configured to generate a third optical signal by combining the first optical signal and the second optical signal; a switch configured to connect any one of a plurality of optical cables connected to the switch with the filter to transmit the third optical signal through any one of the plurality of optical cables; and a controller configured to control the switch by analyzing reflected light of the second optical signal.

Abstract: A communication system comprises a clock generator configured to generate a plurality of system clock signals used to synchronize components included in each of communication nodes in the communication system based on an external clock signal provided by an external clock source located outside the communication system and a physical layer configured to transmit any one of the generated system clock signals to a small cell communicatively connected to an end communication node of the communication system.

Abstract: Disclosed is a beacon-based positioning system. A beacon position in which a beacon is installable is defined in a target space, and a path loss model of radio frequency (RF) signals between all beacon positions and all observation positions of a scanner is determined. Among all possible installation plans for the beacon positions, an installation plan in which different beacon signals, whose RSSIs calculated using the path loss model have significant values, are received in a number greater than or equal to a minimum reference number and a total number of the beacons installed is minimum is determined as an optimal installation plan. The optimization problem of determining the optimal installation plan may be expressed by binary linear programming.

Abstract: An optical communication device including a GPS receiver receiving and outputting a GPS signal from a satellite; a main controller configured to generate and output synchronization data based on the GPS signal; and an optical transceiver configured to generate an optical signal by superposing input payload data and the synchronization data, and to output the optical signal, wherein a first communication channel corresponding to the payload data and a second communication channel corresponding to the synchronization data are different communication channels. According to embodiments, GPS information for synchronization together with payload data, which is information to be transmitted, may be efficiently transmitted between optical communication devices located in remote locations without separate wavelength allocation and connection of an optical cable, by using an auxiliary management and control channel (AMCC).

Abstract: Disclosed is a distributed antenna system (DAS). The DAS includes a DAS controller, which is an OpenFlow controller, and one or more DAS units in order to dynamically control a traffic transmission policy of the DAS units using an OpenFlow protocol, wherein the DAS controller generates and changes a traffic transmission policy by reflecting a traffic transmission policy change request by operator manipulation or a software-defined network supporting application and a need for changing of the traffic transmission policy according to a status of the DAS unit and a status of a port, and the DAS unit transmits received traffic to a destination according to the policy.

Abstract: Provided is an optical communication device including: a first channel card configured to convert an input first signal into a first optical signal and output the first optical signal to any one of a first MUX/DEMUX connected to a first optical line and a second MUX/DEMUX connected to a second optical line; a second channel card configured to convert an input second signal into a second optical signal and output the second optical signal to any one of the first MUX/DEMUX and the second MUX/DEMUX; and a controller configured to monitor states of the first optical line and the second optical line to determine a MUX/DEMUX from which the first optical signal and the second optical signal are respectively output, from among the first MUX/DEMUX and the second MUX/DEMUX.

Abstract: The present invention relates to a method and an apparatus allowing a simultaneous transmission of control signals in a wireless communication system.