# US 10,321,472 B2 · Uplink multi-user transmission method in wireless LAN system and apparatus therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,321,472 B2 - Document ID: US10321472B2 - Status: Granted - Kind: B2 - Application number: 15/310,734 - Filed: 2015-06-08 - Published: 2017-03-23 - Granted: 2019-06-11 - Earliest claimed: 2014-06-08 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Jeongki Kim; Kiseon Ryu; Giwon Park; Suhwook Kim; Hangyu Cho - Web page: https://patentgrep.com/patent/US10321472B2 ## CPC - H04L 27/2602: {Signal structure} - H04L 1/1664: {the supervisory signal being transmitted together with payload signals; piggybacking} - H04L 1/1887: {Scheduling and prioritising arrangements} - H04L 5/0044: {Allocation of payload; Allocation of data channels, e.g. PDSCH or PUSCH} - H04L 5/0058: {Allocation criteria} - H04L 5/0092: {Indication of how the channel is divided} - H04W 72/04: Wireless resource allocation - H04W 72/12: Wireless traffic scheduling - H04W 72/1268: of uplink data flows - H04L 5/0007: {the frequencies being orthogonal, e.g. OFDM(A) or DMT} - H04L 5/0037: {Inter-user or inter-terminal allocation} - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04L 5/0055: {Physical resource allocation for ACK/NACK (for physical mapping arrangements in ARQ protocols H04L1/1861)} - H04L 27/2601: {Multicarrier modulation systems} - H04W 84/12: WLAN [Wireless Local Area Networks] - H04W 88/08: Access point devices - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract The present document relates to a method for efficiently performing uplink multi-user transmission in a wireless LAN system and an apparatus therefor. To this end, an access point (AP) may transmit a downlink multi-user frame to a plurality of STAs, receive an uplink frame including an acknowledgement/non-acknowledgement (ACK/NACK) signal for the downlink multi-user frame and an uplink scheduling request signal from at least two STAs among the STAs, transmit a downlink frame including uplink scheduling information to the at least two STAs on the basis of the uplink scheduling request signal, and receive an uplink multi-user frame including data from the at least two STAs in response thereto. Here, an SIG field of the downlink frame preferably comprises an indicator indicating that the downlink frame includes uplink multi-user scheduling information. ## Claims ### Claim 1 A method for a station (STA) to transmit uplink data in a wireless local area network (WLAN) system, the method comprising: receiving, from an access point (AP), a frame including uplink multi-user (UL MU) scheduling information for the uplink data transmission; and transmitting the uplink data to the AP based on the UL MU scheduling information, wherein the transmission of the uplink data is performed after a SIFS (Short Interframe Space), wherein a start timing of the SIFS is end of the frame, wherein the frame further includes a specific field including null information for extending a length of the frame to delay the start timing of the SIFS, and wherein the STA is provided with an additional time to prepare for the transmission of the uplink data based on the delay of the start timing of the SIFS. ### Claim 2 (depends on 1) The method of claim 1, wherein a length of the specific field is changed in consideration of a time required for the STA to process the UL MU scheduling information. ### Claim 3 (depends on 1) The method of claim 1, wherein the STA skips decoding of the specific field of the frame to earn a processing time for the UL MU scheduling information. ### Claim 4 (depends on 1) The method of claim 1, wherein the frame including the UL MU scheduling information is a trigger frame. ### Claim 5 (depends on 1) The method of claim 1, further comprising: transmitting a buffer status report (BSR) to the AP to assist the AP at determining the UL MU scheduling information. ### Claim 6 (depends on 1) The method of claim 1, further comprising: receiving acknowledgement information to the uplink data from the AP, wherein the acknowledgement information is received within an ACK frame after the transmission of the uplink data. ### Claim 7 (depends on 1) The method of claim 1, wherein the UL MU scheduling information includes: an ID field including identification information of the AP; STA ID fields for identifying each of multiple STAs of the UL MU transmission; resource allocation fields allocating uplink resources to each of the multiple STAs; and control fields for data transmission schemes used by each of the multiple STAs. ### Claim 8 A method for an access point (AP) to receive uplink data from multiple stations (STAs) in a wireless local area network (WLAN) system, the method comprising: transmitting, to the multiple STAs, a frame including uplink multi-user (UL MU) scheduling information for a transmission of the uplink data; and receiving, from the multiple STAs, the uplink data based on the UL MU scheduling information, wherein the reception of the uplink data is performed after a SIFS (Short Interframe Space), wherein a start timing of the SIFS is end of the frame, wherein the frame includes a specific field including null information for extending a length of the frame to delay the start timing of the SIFS, and wherein the STA is provided with an additional time to prepare for the transmission of the uplink data based on the delay of the start timing of the SIFS. ### Claim 9 A station (STA) for transmitting uplink data in a wireless local area network (WLAN) system, the STA comprising: a transceiver configured to receive, from an access point (AP), a frame including uplink multi-user (UL MU) scheduling information for the uplink data transmission, and to transmit the uplink data to the AP based on the UL MU scheduling information; and a processor configured to control the transceiver such that the transmission of the uplink data to be performed after a SIFS (Short Interframe Space), wherein a start timing of the SIFS is end of the frame, wherein the frame further includes a specific field including null information for extending a length of the frame to delay the start timing of the SIFS, wherein the STA is provided with an additional time to prepare for the transmission of the uplink data based on the delay of the start timing of the SIFS. ### Claim 10 An access point (AP) for receiving uplink data from multiple stations (STAs) in a wireless local area network (WLAN) system, the AP comprising: a transceiver configured to transmit, to the multiple STAs, a frame including uplink multi-user (UL MU) scheduling information for a transmission of the uplink data, and to receive, from the multiple STAs, the uplink data based on the UL MU scheduling information; and a processor configured to control the transceiver such that the reception of the uplink data is performed after a SIFS (Short Interframe Space), wherein a start timing of the SIFS is end of the frame, wherein the frame includes a specific field including null information for extending a length of the frame to delay the start timing of the SIFS, and wherein the STA is provided with an additional time to prepare for the transmission of the uplink data based on the delay of the start timing of the SIFS.