Abstract: A method for performing handover between heterogeneous networks by a User Equipment (UE) in a wireless communication system is provided. The method includes periodically sending a first node a measurement report message while being provided a communication service from the first node using a first frequency band, the measurement report message including measurements for the first node and at least one other node using a different frequency band than the first frequency band, and exchanging information, required to perform handover to a second node having a greatest measurement among the at least one other node, with the second node if a handover preparation request message is received from the first node.

Abstract: A method and apparatus are provided for generating a visible light signal according to an amount of data transmission in a first Visible Light Communication (VLC) device. The method includes determining a ratio of an amount of data that has been received from a second VLC device to a total amount of data to be received; determining a visible light signal pattern corresponding to the ratio; generating a visible light signal corresponding to the visible light signal pattern; and outputting the visible light signal.

Abstract: An apparatus for transmitting information using a visible light includes at least three light emitting devices, each being installed based on a predetermined interval and direction, and a data transmitting unit to transmit data by controlling the at least three light emitting devices.

Abstract: Provided herein are communication schemes for combining 5G communication systems with IoT technology to support higher data transmission rate as post-4G systems and systems for the same. The present disclosure may be used in intelligent services (e.g., smart home, smart building, smart city, smart car, connected car, health-care, digital education, retail business, security and safety-related services) based on the 5G communication technology and IoT-related techniques. According to an embodiment of the present disclosure, a method for sensing a channel by a base station in a communication system comprises setting a channel sensing interval for sensing a channel available on an unlicensed band, based on a first start time when the base station starts a signal transmission and the set channel sensing interval, setting a second start time when a channel sensing operation starts, and performing the channel sensing operation during the channel sensing interval from the set second start time.

Abstract: Disclosed is a 5G or pre-5G communication system for supporting a data transmission rate higher than that of a 4G communication system, such as LTE, and subsequent systems. Provided is a random access preamble transmitting method of a terminal for performing an initial access in a communication system, the method comprising the steps of: acquiring system information from a base station; determining a repetition level of a random access preamble by using the acquired system information; and transmitting the random access preamble with a repetitive frequency corresponding to the repetition level in a transmission resource area corresponding to the determined repetition level.

Abstract: A repeater for selecting a channel in a local communication system, and a method thereof are provided. A repeater of a local communication system includes a transceiver configured to perform at least one of transmitting and receiving a signal, and a controller configured to calculate a degree of interference of an available channel with an adjacent channel, the interference caused when a frequency band of the available channel overlaps partially with a frequency band of the adjacent channel, and to determine that the repeater is to use a channel having a smallest degree of interference as a channel.

Abstract: The present invention relates to a position compensation device using visible light communication and a method thereof. To this end, the present invention receives a visible light signal which includes lighting position information from a lighting device to extract the lighting position information from the received visible light signal, and calculates a compensated position of a position compensation device by using the extracted lighting position information if a request for position compensation exists, thereby providing an exact position of a user indoors.

Abstract: Proposed is a method for providing additional information to a mobile communication terminal by means of visible light communication in an information display device having an LED backlight unit. For this purpose, the method of the present invention comprises the steps of: receiving, from a mobile communication terminal, a request for additional information on an object in a content image when a content image is being displayed on a screen of an information display device; determining whether or not there exists additional information corresponding to the request; and controlling, if said additional information does exist, the light emission of the LED backlight unit so as to transmit said additional information in the form of visible light to the mobile communication terminal. Further, according to the present invention, it is possible to provide various additional information corresponding to the request from the mobile communication terminal.

Abstract: A method and apparatus are provided for transmitting wireless power to at least one wireless power receiver. The apparatus includes a communication unit that receives power management information from the at least one wireless power receiver, wherein the power management information includes a power capacity of each of the at least one wireless power receiver; and a controller that analyzes the power management information and determines whether an output capacity of the wireless power transmitter is greater than a total sum of the power capacities of the at least one wireless power receiver.

Abstract: A method for transmitting control information by a base station in a communication system using a plurality of serving cells comprises transmitting is provided. The method includes a terminal, an identifier of a second serving cell identifying where control information regarding a first serving cell is transmitted, transmitting, to the terminal, a predetermined value of a carrier identifier used in the second serving cell, and transmitting the control information regarding the first serving cell including the carrier identifier having the predetermined value through the second serving cell.

Abstract: A method and apparatus are provided for generating a visible light signal according to an amount of data transmission in a first Visible Light Communication (VLC) device. The method includes determining a ratio of an amount of data that has been received from a second VLC device to a total amount of data to be received; determining a visible light signal pattern corresponding to the ratio; generating a visible light signal corresponding to the visible light signal pattern; and outputting the visible light signal.

Abstract: Disclosed is a method of controlling a communication system including one or more sensors attached to a user, a wireless communication apparatus, and a coordinator.

Abstract: Disclosed is a control method of a communication system including at least one sensor that a user wears, a wireless communication apparatus and a coordinator.

Abstract: A method and apparatus for generating a visible signal to enable a user to confirm the amount of data transmission in Visible Light Communication (VLC) are provided. The apparatus previously acquires amount information of data which is to transmit or receive, and acquires the ratio of the amount of data transmitted to a receiving-side VLC device from a transmitting VLC device or the amount of data transmitted from the transmitting-side VLC device received by the receiving VLC device to the total amount of data. The apparatus determines a visible light output pattern corresponding to the data ratio and generates visible light of the determined output pattern.

Abstract: According to one embodiment, a photo detector-combined illuminance sensor includes a circuit for a Photo Detector (PD) function to detect the illuminance of the ambient environment. The illuminance sensor operates under the control of a controller in a visible light communication terminal. When an optical signal detected by the illuminance sensor is a visible light communication signal, the controller switches to cause the illuminance sensor to operate as the photo detector for the visible light communication in a visible light communication mode.

Abstract: A method provides additional information from a server to a visible light communication terminal through visible light communication in an information display device having a Light Emitting Diode (LED) backlight unit. To this end, if content data regarding an image output through a screen of an information display device is provided from a server, it is determined whether additional information regarding an object of the image is included in the content data, and if so, the additional information is acquired from the content data. The information display device controls light emission of an LED backlight unit of a display unit based on the additional information, thus performing visible light communication. As such, various additional information regarding an object of an image displayed at a particular position of a current screen of the information display device can be provided to a visible light communication terminal.

Abstract: A method for aligning among visible light communication devices comprises the following steps: generating a visible light signal and transmitting same to a corresponding device; determining whether the visible light signal that is output via the screen of the device is identifiable; correcting the color of the visible light signal that is output on the screen if the visible light signal is not identifiable; and using the visible light signal that is corrected to perform alignment for visible light communicating with the corresponding device.

Abstract: Methods and apparatus are provided for measuring a position of a mobile terminal. A first position is calculated by using a GPS signal. A visible light communication mode of the mobile terminal is activated, when the first position exceeds a predetermined error range. Visible light communication device position information is received. A third position is calculated by using a second position, which corresponds to a position prior to the first position, and the visible light communication device position information.

Abstract: An apparatus and a method for determining a gateway using lower power are provided. The method includes setting probing transmission power for setting the gateway, transmitting a probing request message to another mobile station existing in a cluster with the set probing transmission power, when a probing response message is received from the other mobile station, generating a probing response list for the mobile station having transmitted the probing response message, determining whether a cluster list for mobile stations existing in the cluster corresponds to the probing response list, and determining a gateway mobile station according to a result of the determination as to whether the cluster list for mobile stations existing in the cluster corresponds to the probing response list.

Abstract: An optical communication apparatus includes an optical signal transmitting unit to output an optical signal; an optical signal receiving unit to receive an optical signal; a retro-reflector to retro-reflect the received optical signal in a direction opposite to an incident angle of the received optical signal; and a control unit to direct the retro-reflector to receive the optical signal and to retro-reflect a response signal, which includes the received optical signal and data to be transmitted, in response to the received optical signal.