# US 10,374,767 B2 · Method for transmitting frame type indication information in wireless LAN system and device therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,767 B2 - Document ID: US10374767B2 - Status: Granted - Kind: B2 - Application number: 15/767,701 - Filed: 2016-10-14 - Published: 2018-10-04 - Granted: 2019-08-06 - Earliest claimed: 2015-10-14 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Dongguk Lim; Jinyoung Chun; Jinsoo Choi; Hangyu Cho; Jinmin Kim; Eunsung Park - Web page: https://patentgrep.com/patent/US10374767B2 ## CPC - H04L 27/2602: {Signal structure} - H04B 7/0684: {using different training sequences per antenna} - H04L 5/00: Arrangements affording multiple use of the transmission path - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04L 5/0094: {Indication of how sub-channels of the path are allocated} - H04L 27/2603: {Signal structure ensuring backward compatibility with legacy system} - H04W 72/04: Wireless resource allocation - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04B 7/0413: MIMO systems - H04L 5/0007: {the frequencies being orthogonal, e.g. OFDM(A) or DMT} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04B: TRANSMISSION - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Provided is a method for a first station (STA) transmitting a frame to a second STA in a wireless LAN system. To this end, the first STA generates a wireless frame comprising a first part (L-part) for a first-type STA and a second part (HE-part) for a second-type STA, wherein the first part comprises a legacy short training field (L-STF), a legacy long training field (L-LTF) and a legacy signaling field (L-SIG), and the length of the L-SIG is set so as to indicate that the wireless frame is a frame of different types according to the remainder when the length of the L-SIG is divided by a predetermined natural number. ## Claims ### Claim 1 A method for a first station (STA) to transmit a frame to a second STA in a wireless local area network (WLAN) system, the method comprising: generating a radio frame including a first part (L-part) for a first type STA and a second part (HE-part) for a second type STA; and transmitting the generated frame to the second STA, wherein the first part includes a legacy short training field (L-STF), a legacy long training field (L-LTF) and a legacy signaling (L-SIG) field, and wherein a length of the L-SIG field is configured to indicate different types of the radio frame based on a remainder from a length of the L-SIG field divided by a predetermined natural number. ### Claim 2 (depends on 1) The method of claim 1, wherein the first type STA is an STA supporting an IEEE 802.11ac system and earlier versions of the IEEE 802.11ac system, and the predetermined natural number is 3. ### Claim 3 (depends on 1) The method of claim 1, wherein the length of the L-SIG field is determined by: Length = ⌈ TXTIME - 20 4 ⌉ × 3 - 3 ± m wherein the “TXTIME” indicates a predetermined length determined according to lengths of each part of the radio frame, and wherein the ‘m’ has a value indicating the type of the radio frame. ### Claim 4 (depends on 3) The method of claim 3, wherein the radio frame is a frame for the first type STA when the ‘m’ has a value of 0. ### Claim 5 (depends on 3) The method of claim 3, wherein the radio frame is a first type frame or a second type frame both for the second type STA when the ‘m’ has a value of 1 or 2. ### Claim 6 (depends on 5) The method of claim 5, wherein the first type frame is a general frame for the second type STA, and wherein the second type frame is a frame for the second type STA to communicate with a transmission rate lower than a predetermined threshold. ### Claim 7 (depends on 5) The method of claim 5, wherein the first type frame includes a HE-SIG A field and a HE-SIG B field in the second part (HE-Part), and wherein the second type frame does not include the HE-SIG B field in the second part (HE-Part). ### Claim 8 (depends on 5) The method of claim 5, wherein the first type frame includes a HE-SIG A field over 2 symbols in the second part (HE-Part), and wherein the second type frame includes the HE-SIG A field over 1 symbol in the second part (HE-Part). ### Claim 9 (depends on 8) The method of claim 8, wherein the HE-SIG A field of the second type frame is mapped on 1 symbol, and repeated over 2 symbols. ### Claim 10 (depends on 1) The method of claim 1, wherein the first part includes an RL-SIG field repeatedly transmitting the L-SIG field, and wherein first indication information is additionally transferred by using a polarity bit or a bi-polar sequence multiplied to the RL-SIG field. ### Claim 11 (depends on 1) The method of claim 1, wherein the first part includes an RL-SIG field repeatedly transmitting the L-SIG field, and wherein second indication information is additionally transferred by using one or more bits available in the RL-SIG field when the radio frame is transmitted for the first type STA. ### Claim 12 A station device for transmitting a frame in a wireless LAN system, the station device comprising: a processor configured to generate a radio frame including a first part (L-part) for a first type STA and a second part (HE-part) for a second type STA; and a transceiver configured to transmit the radio frame transferred from the processor to another station, wherein the processor generates the first part to include a legacy short training field (L-STF), a legacy long training field (L-LTF) and a legacy signaling (L-SIG) field, and wherein a length of the L-SIG field is configured to indicate different types of the radio frame based on a remainder from a length of the L-SIG field divided by a predetermined natural number. ### Claim 13 (depends on 12) The station device of claim 12, wherein the first type STA is an STA supporting an IEEE 802.11ac system and earlier versions of the IEEE 802.11ac system, and the predetermined natural number is 3. ### Claim 14 (depends on 12) The station device of claim 12, wherein the processor determines a length of the L-SIG field by: Length = ⌈ TXTIME - 20 4 ⌉ × 3 - 3 ± m wherein the “TXTIME” indicates a predetermined length determined according to lengths of each part of the radio frame, and wherein the ‘m’ has a specific value indicating the type of the radio frame. ### Claim 15 (depends on 14) The station device of claim 14, wherein the radio frame is a frame for the first type STA when the ‘m’ has a value of 0, and the radio frame is a first type frame or a second type frame both for the second type STA when the ‘m’ has a value of 1 or 2.