Abstract: Provided is a node unit which is branch-connected to another communication node via a transport medium, the node unit comprising: a delay measurement unit which transmits a test signal for measuring a delay to an adjacent node unit of the branch-connected upper stage via the transport medium and detects a loopback signal to which the test signal is looped back via the adjacent node unit of the upper stage, thereby measuring an upper stage transmission delay between the adjacent node unit of the upper stage and the node unit; a delay summation unit which, when an adjacent node unit of the branch-connected lower stage exists, receives a lower stage transmission delay transmitted from the adjacent node unit of the lower stage, and calculates a summed transmission delay by summing the upper stage transmission delay and the lower stage transmission delay; and a control unit which transmits the summed transmission delay to the adjacent node unit of the upper stage.

Abstract: An operating method of a repeater, the operating method comprises: receiving a first communication signal according to a first mobile communication standard, generating a time division duplex (TDD) switching signal based on information about a start point of the received first communication signal, and controlling switching of an uplink and a downlink of a repeater that relays a second communication signal according to a second mobile communication standard based on the generated TDD switching signal.

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: A satellite signal relay system according to an embodiment of the inventive concept includes: a plurality of remote units configured to receive an analog satellite signal, to convert the analog satellite signal into a digital satellite signal, to generate a characteristic signal for the analog satellite signal, to generate a transmission frame based on the digital satellite signal and the characteristic signal, and to convert the transmission frame into an optical transmission frame; and a central unit configured to convert optical transmission frames received from the plurality of remote units into transmission frames through an optical transmission medium, respectively, to extract a digital satellite signal and a characteristic signal from each of the converted transmission frames, and to convert any one of the extracted digital satellite signals into an analog satellite signal based on the extracted characteristics signals.

Abstract: A distributed antenna system includes a plurality of head-end devices for each receiving mobile communication signals from at least one corresponding base station, a hub communicatively coupled to the plurality of head-end devices, and a plurality of remote devices communicatively coupled to the hub, wherein the hub configured to distribute the mobile communication signals received from each of the plurality of head-end devices to the plurality of remote devices, wherein each of the plurality of remote devices is remotely disposed to transmit the distributed mobile communication signals to a terminal in service coverage, and wherein the hub includes a mixing processing stage configured to perform digital mixing processing on the mobile communication signals respectively received from the plurality of head-end devices, and a crest factor reduction (CFR) module disposed posterior to the mixing processing stage, with respect to a signal transmission direction.

Abstract: A node unit of a distributed antenna system includes a power supply unit for supplying power for operating the node unit, a digital part operated by the power supplied from the power supply unit, the digital part performing digital processing on input relay signals and outputting the digital-processed relay signals, and a controller for disabling an output of the digital part in response to a first control command for instructing a reset of the power supply unit or a second control command for instructing a reset of the digital part.

Abstract: According to an aspect of the inventive concept, there is provided an interference cancellation repeater includes: a signal transceiver configured to cancel an interference signal from an RF input signal and to output an RF output signal from which the interference signal has been canceled; and a controller configured to control a power mode of the signal transceiver by measuring traffic of a first signal in the signal transceiver.

Abstract: Provided is a node unit which is branch-connected to another communication node via a transport medium, the node unit comprising: a delay measurement unit which transmits a test signal for measuring a delay to an adjacent node unit of the branch-connected upper stage via the transport medium and detects a loopback signal to which the test signal is looped back via the adjacent node unit of the upper stage, thereby measuring an upper stage transmission delay between the adjacent node unit of the upper stage and the node unit; a delay summation unit which, when an adjacent node unit of the branch-connected lower stage exists, receives a lower stage transmission delay transmitted from the adjacent node unit of the lower stage, and calculates a summed transmission delay by summing the upper stage transmission delay and the lower stage transmission delay; and a control unit which transmits the summed transmission delay to the adjacent node unit of the upper stage.

Abstract: An interference cancellation repeater according to the inventive concept includes: a first transmission/reception processing unit configured to adjust a gain of a radio frequency (RF) input signal input via a link antenna communicatively coupled to a base station; an interference canceller configured to cancel and output an interference signal from an output signal of the first transmission/reception processing unit; and a gain controller configured to extract a signal with constant magnitude regardless of a change in user traffic from the output signal of the interference canceller, and to adjust the gain of the RF input signal to a predetermined level by controlling the first transmission/reception processing unit based on the extracted signal.

Abstract: A node unit of distributed antenna system, the node unit comprises a delay measuring part configured to transmit a first test signal for delay measurement to an upper adjacent node unit and detect the first test signal looped back via the upper adjacent node unit and measure a round trip delay between the node unit and the upper adjacent node unit, and a delay providing part disposed on a signal transmission path through which a second test signal for delay measurement, to be transmitted from a lower adjacent node unit, is to be looped back to the lower adjacent node unit, and configured to provide a delay corresponding to the round trip delay.

Abstract: A satellite signal relay system according to an embodiment of the inventive concept includes: a plurality of remote units configured to receive an analog satellite signal, to convert the analog satellite signal into a digital satellite signal, to generate a characteristic signal for the analog satellite signal, to generate a transmission frame based on the digital satellite signal and the characteristic signal, and to convert the transmission frame into an optical transmission frame; and a central unit configured to convert optical transmission frames received from the plurality of remote units into transmission frames through an optical transmission medium, respectively, to extract a digital satellite signal and a characteristic signal from each of the converted transmission frames, and to convert any one of the extracted digital satellite signals into an analog satellite signal based on the extracted characteristics signals.

Abstract: There is provided an optical signal monitoring device and an optical signal monitoring system of a wavelength division multiplexing based network including: an input unit configured to receive each of downlink signals and uplink signals; a wavelength division multiplexing filter configured to separate the downlink signals and the uplink signals by wavelength; an optical power measurement module configured to measure optical power of each signal separated by wavelength; and a controller configured to determine whether an optical signal is abnormal based on optical power information measured by the optical power measurement module.

Abstract: Provided are an optical relay system and a method for setting identification information of a remote device in an optical relay system. In particular, provided are an optical relay system and a method for setting identification information of a remote device in an optical relay system in which a donor device generates unique identification information of a remote device based on temporary identification information and characteristic information received from the remote device to automatically set identification information of the remote device, and as a result, the optical relay system can be normally implemented rapidly in initial installation of the optical relay system or a change of an optical relay system environment and convenience of a manager and reliability of a mobile communication service can be improved.

Abstract: A distributed antenna system (DAS) according to an aspect of the inventive concept includes a first node unit for receiving first digital data in accordance with a digital interface standard from a base station, converting the first digital data into second digital data in accordance with a DAS frame standard, and a second node unit for receiving the second digital data from the first node unit, and restoring the first digital data based on the second digital data.

Abstract: A base station signal matching device configured to receive a base station signal from a base transceiver station (BTS), the base station signal matching device is embedded in a relay device, and the base station signal matching device includes a signal attenuation unit configured to receive the base station signal and attenuate the input power level of the base station signal; and a signal matching unit configured to receive the base station signal passing through the signal attenuation unit to match the base station signal suitable for signal processing of the relay device.

Abstract: An optical line testing device for measuring at least a cutting position of an optical line according to the present invention includes: a first wavelength tunable laser source configured to generate a first optical signal in which a plurality of wavelengths appear alternately and periodically; a second wavelength tunable laser source configured to generate a second optical signal which is identical to the first optical signal but has an adjustable delay time; and an interferometer configured to cause interference between a reflected optical signal, corresponding to the first optical signal, which is returning after having been emitted to the optical line, and the second optical signal to output an interference signal.

Abstract: A head-end device according to an embodiment includes: a plurality of base station interfacing units configured to interface each of transmission/reception signals that are exchanged between the head-end device and a plurality of base stations; and a head-end control unit configured to receive an upper interfacing unit signal transmitted from an upper base station interfacing unit from among the plurality of base station interfacing units, and sequentially transmit the received upper interfacing unit signal to a lower base station interfacing unit.

Abstract: A method of recovering a synchronization detection error according to an embodiment includes: determining whether a base station signal input to a head-end device is detected; determining whether a head-end signal output from the head-end device, which is obtained by processing the base station signal by the head-end device, is detected by a lower device of the head-end device; determining whether synchronization of the head-end signal is detected based on the head-end signal input to the lower device; and changing a set frequency band or performing automatic gain control of the head-end device based on whether the base station signal is detected, whether the head-end signal is detected, and whether the synchronization of the head-end signal is detected

Abstract: A signal processing device according to an exemplary embodiment of the inventive concept can integrate a power amplifier, a duplexer, and a linearizer as a module to improve the convenience of management and to improve flexibility and extensibility so as to be transformable corresponding to a change in system development concept.

Abstract: According to one mode of the inventive concept, an amplification device includes a first amplifier configured to amplify an input multi-band signal to a first level, a separating unit configured to separate the multi-band signal having the first level into a first band signal and a second band signal, and a second amplifier configured to amplify the second band signal to a second level.