Abstract: A method and an apparatus for allocating a flexible transmission slot in a wireless local area network (LAN) system are disclosed. A flexible transmission slot allocation method of an access point (AP) in a wireless local area network (WLAN) system according to an exemplary embodiment includes transmitting a beacon including a traffic indication map (TIM) bit to a station, receiving a power save poll (PS-Poll) from the station in a slot implicitly allocated by the TIM bit, and transmitting an acknowledgement (ACK) including transmission slot allocation information on downlink data to the station.

Abstract: Provided is slot use control apparatus and method, including an access point (AP) to control a slotted channel access of a station (STA) in a wireless local area network (WLAN) includes generating a synchronization (synch) frame including an identification value indicating an STA allocated to a slot, and broadcasting the generated synch frame when a channel is in an idle state at a start point of the slot.

Abstract: A scanning method in a wireless local area network (WLAN) system is provided. The scanning method includes transmitting, by a station, a probe request frame and receiving, by the station, a probe response frame from an access point (AP). The AP determines whether to transmit the probe response frame in response to the probe request frame using information indicated by the probe request frame.

Abstract: A combined heat exchanger module includes a first upper tank introducing cooling water into the combined heat exchanger module, a lower tank introducing the cooling water into or discharging the cooling water from the combined heat exchanger module, a second upper tank for discharging the cooling water from the combined heat exchanger module, first heat radiating channels connected with the first upper tank and the lower tank, second heat radiating channels connected with the lower tank and the second upper tank, and thermoelectric elements, in which each of the thermoelectric elements has a first surface in contact with the second heat radiating channels and a second surface exposed to air, thereby performing heating of air by use of both the cooling water and the thermoelectric elements or performing cooling of the cooling water by use of the thermoelectric elements.

Abstract: A coolant heating apparatus for an electric vehicle includes a sheath heater formed in a coil form at a center side of the coolant heating apparatus; one or more inner tubes, one of which has an inlet formed at one side thereof for introduction of coolant, the one or more inner tubes being arranged to surround the sheath heater or to be surrounded by the sheath heater, and the one or more inner tubes having a plurality of through-holes formed on respective outer peripheral surfaces thereof so that the coolant introduced into the inlet is discharged through the through-holes; and an outer tube surrounding the sheath heater and the one or more inner tubes and having an outlet formed at one side thereof so that the coolant heated by the sheath heater is introduced through the through-holes of the one or more inner tubes and is discharged through the outlet.

Abstract: A baseband signal generation method includes mapping frequency-domain data for a plurality of component carriers to subcarrier resources; performing a frequency shift on the frequency domain-data allocated to the subcarrier resources; generating a time-domain signal by performing IFFT on the frequency-shifted frequency-domain data using a single IFFT block; and generating a time-domain baseband signal by adding a CP to the time-domain signal.

Abstract: A wireless communication method and apparatus in a wireless local area network (WLAN) system are disclosed.

Abstract: A timing control method, performed by a first DU including a processor and a modem in a base station supporting function-splitting, includes obtaining, by the processor, first time information from a CU included in the base station; obtaining, by the processor, synchronization information with a first system based on the first time information; identifying, by the processor, a change time point of an SFN based on the synchronization information; generating, by the processor, a first timing control signal including a signal indicating a changed SFN and a first tick signal having a same periodicity as a change periodicity of the SFN when the SFN is changed; and providing, by the processor, the first timing control signal to the modem.

Abstract: A method for transmitting and receiving signals, performed by a terminal, in a C-RAN environment, includes sequentially transmitting fixed beams; receiving, from at least one first TRP determined as TRP(s) performing signal transmission and reception with the terminal among the plurality of TRPs, control information including information on whether to transmit a reference signal for reception of downlink data and an index of a transmission beam selected for uplink transmission; and receiving the downlink data from the at least one first TRP, and demodulating the downlink data by using a reception beam weight derived from a weight used for transmission of the fixed beams or by using the reference signal.

Abstract: Disclosed are a method and an apparatus for communication using fronthaul interfaces. An operation method of a first communication node includes transmitting a section type 8 message #1 including numerology-related information #1; transmitting a section type 9 message #1 including channel information of each of one or more second communication nodes indicated by the section type 8 message #1 and the numerology related information #1, transmitting a section type 8 message #2 including numerology-related information #2 other than the numerology-related information #1; and transmitting a section type 9 message #2 including channel information of each of one or more third communication nodes indicated by the section type 8 message #2 and the numerology-related information #2.

Abstract: Disclosed are a frame transmission method using a selective beamforming and a communication apparatus to perform the frame transmission method. The communication apparatus may determine a beamforming matrix based on classification information in which a plurality of subcarriers used for communication is classified into a plurality of frequency units, may map a long training field (LTF) sequence to the beamforming matrix, and transmit a beamforming training (BF-T) frame including the mapped LTF sequence to a plurality of stations, may receive, from the plurality of stations having receiving the BF-T frame, feedback information generated based on a reception strength of the BF-T frame, and may allocate frequency units to data frames to be transmitted to the plurality of stations based on the feedback information, and transmit the data frames using the allocated frequency units. The reception strength of the BF-T frame may be determined at each station for each frequency unit.

Abstract: A wireless communication method and apparatus in a wireless local area network (WLAN) system are disclosed. A wireless communication method according to one embodiment may include generating a high-efficiency Wi-Fi (HEW) frame including at least one of an HEW-SIG-A field and an HEW-SIG-B field which include channel information for communications according to an Orthogonal Frequency-Division Multiple Access (OFDMA) mode, and transmitting the generated HEW frame to a reception apparatus.

Abstract: Provided is a method and apparatus for allocating resources in a wireless local area network (WLAN) system, the method including determining a restricted access bandwidth (RAB) interval based on at least a bandwidth or a partial bandwidth among a plurality of bandwidths, and setting a restricted access window (RAW) of a time domain based on the RAB interval.

Abstract: Provided is a sector discovery apparatus and method, the method including setting, by an AP in a WLAN system, an omni-beacon interval for transmitting an omnidirectional beacon and sector beacon intervals for transmitting a sector beacon with respect to one of a plurality of sectors which are spatially divided, transmitting the sector beacon to a current sector among the plurality of sectors, transmitting, to the current sector, a transmission frame indicating sectorized transmission or a transmission frame indicating omnidirectional transmission, in a sector interval between the sector beacon intervals, and receiving, from a terminal located in the current sector, a response frame indicating an association performed by receiving the transmission frame indicating the sectorized transmission.

Abstract: Disclosed is a compressor including a housing, and a motor including a stator to be interference fitted into and fixed to an inner circumferential surface of the housing and a rotor rotatable inside the stator. The stator includes an annular back yoke disposed inside the housing, a plurality of teeth extending radially inward from the back yoke, and a coil wound on the plurality of teeth. The back yoke includes a deformation portion compressed and deformed by the housing while the stator is interference fitted into the inner circumferential surface of the housing, a contact portion which protrudes radially outward from the deformation portion and being in contact with the housing, and a cavity formed on a radial inner side of the deformation portion into which which the deformation portion is deformed.

Abstract: Provided is a wireless communication method performed at an access point to enhance the transmission efficiency in a wireless local area network (WLAN) system, the method including scheduling a transmission time of an enhanced traffic indicator map (TIM) frame based on a type of a station, and transmitting a second beacon including the enhanced TIM frame to the station at a point in time aside from a transmission point in time of a first beacon.

Abstract: Disclosed is an air conditioning apparatus for a vehicle, the air conditioning apparatus including: an air conditioning duct forming a passage for conditioned air, and provided with an outlet on a wall surface thereof for directing conditioned air. A door is provided inside the air conditioning duct, with a rotation shaft being provided on a wall surface opposite to the wall surface of the air conditioning duct. The door opens and closes the air conditioning duct by a rotation thereof. A partition wall protrudes from a surface of the door along the wall surface of the air conditioning duct. The partition wall opens and closes the outlet in response to the rotation of the door.

Abstract: Disclosed are a frame transmission method using a selective beamforming and a communication apparatus to perform the frame transmission method. The communication apparatus may determine a beamforming matrix based on classification information in which a plurality of subcarriers used for communication is classified into a plurality of frequency units, may map a long training field (LTF) sequence to the beamforming matrix, and transmit a beamforming training (BF-T) frame including the mapped LTF sequence to a plurality of stations, may receive, from the plurality of stations having receiving the BF-T frame, feedback information generated based on a reception strength of the BF-T frame, and may allocate frequency units to data frames to be transmitted to the plurality of stations based on the feedback information, and transmit the data frames using the allocated frequency units. The reception strength of the BF-T frame may be determined at each station for each frequency unit.

Abstract: Disclosed are a frame transmission method and a communication device performing the same. The communication device transmits a null data packet (NDP)-announcement (NDP-A) including information on a plurality of communication devices participating in interference alignment and transmits an NDP including a common signal field and a common training field commonly applied to the plurality of communication devices.

Abstract: The present disclosure relates to a composition for a worm wheel having excellent durability and moisture absorption resistance and a worm wheel manufactured using the same. In one embodiment, the composition for a worm wheel includes about 30 wt % to about 70 wt % of a polyketone copolymer and about 30 wt % to about 70 wt % of a polyamide resin, and the composition for a worm wheel has a friction coefficient of about 0.3 or less as measured in accordance with JIS K7218, an abrasion loss of about 0.002 g or less as measured in accordance with JIS K7218, and a moisture absorption rate of about 4% or less as measured in accordance with ASTM D570 (23° C. and 50 RH %).