Abstract: Disclosed are a method and device for transmitting a frame. The method for transmitting a frame includes a step of generating A-MPDU (aggregate MAC protocol data unit) and a step of transmitting A-MPDU. The A-MPDU includes a first AMPDU subframe and a second A-MPDU subframe, wherein the first A-MPDU subframe includes a data block, and the second AMPDU subframe includes an FEC (Forward Error Correction) coding block which is additionally used in the decoding of the data block. Thus, the STA is capable of preventing unnecessary power consumption of STA by selectively determining whether FEC information is received according to whether an error occurred in the decoded data.

Abstract: The present invention relates to a method of performing channel sounding in a wireless LAN system. The method includes transmitting a Null Data Packet Announcement (NDPA) frame for providing notice of an NDP to be transmitted, and transmitting the NDP and receiving a feedback frame from a station (STA). The feedback frame includes channel state information created on the basis of the NDP. The NDP includes a signal field and at least one long training field (LTF) for a multiple input multiple output channel. The signal field includes a repetitive instruction subfield. The repetitive instruction subfield provides instruction on whether orthogonal frequency division multiplexing (OFDM) symbol repetition is applied to the at least one LTF.

Abstract: Provided is a data transceiving method performed by a station (STA) in a wireless LAN system. The method comprises: receiving subgrouping parameter information from an access point (AP); determining whether a frame buffered in the STA subgroup in which the STA is contained exists or not based on the subgrouping parameter information; receiving a TIM element in a channel access interval for the STA subgroup from the AP if the buffered frame exists; and exchanging the AP and the frame in the channel access interval based on the TIM element.

Abstract: The present invention relates to a method for performing channel sounding by means of an access point (AP) in a wireless LAN system. The method includes the steps of transmitting a null data packet announcement (NDPA) frame to notify that an NDP is to be transmitted, transmitting the NDP, and receiving a feedback frame from a station (STA). The NDP includes a signal field. The signal field of the NDP is transmitted through two orthogonal frequency division multiplexing (OFDM) symbols. One of the two OFDM symbols is a repeated OFDM symbol signifying that the other is repeated.

Abstract: Provided is a data transceiving method performed by a station (STA) in a wireless LAN system. The method comprises receiving a channel access information element from an access point, said channel access information element containing STA group information and channel access interval information, said STA determining whether the channel access interval specified by the channel access interval information is for the STA based on the STA group information; and transceiving data to/from said access point during the channel access interval if the channel access interval is for the STA.

Abstract: A method for receiving a beacon frame comprises the steps of: receiving a first beacon frame which contains guard interval type information; determining a second beacon frame which is to be received after the first beacon frame on the basis of the guard interval type information; and receiving the second beacon frame, wherein the guard interval type information may be information which is related to a guard interval used when the second beacon frame is transmitted.

Abstract: Provided is a communication method by a station (STA) that operates in a power safe mode in a wireless LAN system. The method comprises: transmitting a probe request frame to an access point (AP), wherein the probe request frame includes system information identification information for identifying system information acquired by the STA; and receiving a probe response frame as a response to the probe request frame from the AP. The probe response frame includes a time stamp value related to the point of time of transmitting the probe response frame, and if it is determined, based on the system information identification information, that updated information which is not included in said acquired system information exists, the probe response frame further includes said updated information. Also provided is a communication method by an access point (AP) in a wireless LAN system.

Abstract: Provided is a method for transmitting a data unit in a wireless local area network system, according to one embodiment. The method comprises transmitting a signal field, transmitting a first data symbol for a first data field, and transmitting a second data symbol for a second data field. The signal field, the first data symbol, and the second data symbol are transmitted through a 1 MHz channel bandwidth having a band of 1 GHz or less. Two pilot tones are inserted to each of the first data symbol and the second data symbol.

Abstract: A communication method based on identifying information assignment in a wireless local area network (WLAN) system, performed by a station (STA), is provided. The method includes receiving an identifier assignment message from an access point (AP), wherein the identifier assignment message comprises identifying information for the STA, and TIM offset information for a time point at which at least one traffic indication map (TIM) element for the STA starts to be transmitted; receiving a first TIM element from the AP at a time point indicated by the TIM offset information; determining whether the first TIM element comprises the identifying information; and receiving a first data frame from the AP if the first TIM element contains the identifying information.

Abstract: Disclosed are a method and apparatus for transmitting a training field. The method for transmitting a training field in a wireless LAN system comprises the steps of: transmitting additional long training field (LTF) indication information; and transmitting a frame including the additional LTF and partitioned data fields. The additional LTF comprises a field for demodulating the partitioned data fields included in the frame, the additional LTF indication information includes information on the location of the additional LTF included in the frame, and the partitioned data field includes at least one sub-field. Accordingly, the present invention can enhance channel estimation performance.

Abstract: In an aspect, a method of receiving a data unit, performed by an Access Point (AP), in a Wireless LAN (WLAN) system is provided. The method includes transmitting a signal protection frame, the signal protection frame comprising a group ID field indicating a Multiple Input Multiple Output (MIMO) transmission STA group including a first station (STA) and a second STA; and, a spatial stream field indicating a number of spatial streams allocated to each of member STAs included in the MIMO transmission STA group; receiving a first preamble for a first data unit from the first STA; receiving a second preamble for a second data unit from the second STA; and simultaneously receiving the first data unit from the first STA and the second data unit from the second STA.

Abstract: A method for communication performed by a station in a wireless local area network system is provided. The method includes receiving a first change sequence from an access point, transmitting a probe request frame to an access point in order to request updated system information, the probe request frame including the first change sequence, and receiving a probe response frame from the access point in response to the probe request frame. The probe response frame includes a second change sequence. The first change sequence and the second change sequence indicate a change of system information within a basic service set (BSS).

Abstract: Provided is a method for transmitting a data unit in a wireless local area network system, according to one embodiment. The method comprises transmitting a signal field, transmitting a first data symbol for a first data field, and transmitting a second data symbol for a second data field. The signal field, the first data symbol, and the second data symbol are transmitted through a 1 MHz channel bandwidth having a band of 1 GHz or less. Two pilot tones are inserted to each of the first data symbol and the second data symbol.

Abstract: A method for transmitting a data unit, performed by a transmitting station, in a wireless local area network system is provided. The method includes generating a repeated bit sequence, generating an interleaved bit sequence by interleaving the repeated bit sequence, generating at least one symbol by modulating the interleaved bit sequence, generating at least one OFDM symbol by performing IDFT (Inverse Discrete Fourier Transform) on the at least one symbol and transmitting the at least one OFDM symbol.

Abstract: Disclosed are a method and an apparatus for transmitting a channel switching information. A method for transmitting switching information of an operating channel may comprises the step of: receiving a candidate channel frame including channel switch candidate information through the operating channel, and preferentially scanning a candidate operation channel induced based on the channel switch candidate information if the operating channel is changed, wherein the candidate operation channel may be a channel having a possibility of being preferentially selected when the operating channel is changed to another channel. As a result, when an access point (AP) shifts the operating channel, the shifted channel can be quickly scanned and associated with AP.

Abstract: A communication method based on identifying information assignment in a wireless local area network (WLAN) system, performed by a station (STA), is provided. The method includes receiving an identifier assignment message from an access point (AP), wherein the identifier assignment message comprises identifying information for the STA, and TIM offset information for a time point at which at least one traffic indication map (TIM) element for the STA starts to be transmitted; receiving a first TIM element from the AP at a time point indicated by the TIM offset information; determining whether the first TIM element comprises the identifying information; and receiving a first data frame from the AP if the first TIM element contains the identifying information.

Abstract: In an aspect, a method of receiving a data unit, performed by an Access Point (AP), in a Wireless LAN (WLAN) system is provided. The method includes transmitting a signal protection frame, the signal protection frame comprising a group ID field indicating a Multiple Input Multiple Output (MIMO) transmission STA group including a first station (STA) and a second STA; and, a spatial stream field indicating a number of spatial streams allocated to each of member STAs included in the MIMO transmission STA group; receiving a first preamble for a first data unit from the first STA; receiving a second preamble for a second data unit from the second STA; and simultaneously receiving the first data unit from the first STA and the second data unit from the second STA.

Abstract: Provided is a data transceiving method performed by a station (STA) in a wireless LAN system. The method comprises receiving a channel access information element from an access point, said channel access information element containing STA group information and channel access interval information, said STA determining whether the channel access interval specified by the channel access interval information is for the STA based on the STA group information; and transceiving data to/from said access point during the channel access interval if the channel access interval is for the STA.

Abstract: A method of communication based on battery in a wireless LAN system is provided. The method includes receiving, by a station (STA), a battery lifetime request message from an access point (AP), wherein the battery lifetime request message includes a battery lifetime report interval field and battery lifetime report threshold field, the battery lifetime report interval field indicating an interval at which the STA report a battery lifetime, the battery lifetime report threshold field indicating a threshold of the battery lifetime and transmitting, by the STA, a first battery lifetime report message including information indicating a first battery lifetime.

Abstract: The present invention relates to a method of performing channel sounding in a wireless LAN system. The method includes transmitting a Null Data Packet Announcement (NDPA) frame for providing notice of an NDP to be transmitted, and transmitting the NDP and receiving a feedback frame from a station (STA). The feedback frame includes channel state information created on the basis of the NDP. The NDP includes a signal field and at least one long training field (LTF) for a multiple input multiple output channel. The signal field includes a repetitive instruction subfield. The repetitive instruction subfield provides instruction on whether orthogonal frequency division multiplexing (OFDM) symbol repetition is applied to the at least one LTF.