# US 10,375,683 B2 · Trigger frame in wireless local area network > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,375,683 B2 - Document ID: US10375683B2 - Status: Granted - Kind: B2 - Application number: 15/587,135 - Filed: 2017-05-04 - Published: 2017-11-09 - Granted: 2019-08-06 - Earliest claimed: 2016-05-06 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Lochan Verma; Sameer Vermani; Bin Tian; Lin Yang; Raja Banerjea; Alfred Asterjadhi - Web page: https://patentgrep.com/patent/US10375683B2 ## CPC - H04W 52/146: {Uplink power control} - H04L 5/0023: {Time-frequency-space} - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04L 27/2601: {Multicarrier modulation systems} - H04L 27/2613: {Structure of the reference signals} - H04L 27/26136: {Pilot sequence conveying additional information} - H04W 16/14: Spectrum sharing arrangements {between different networks} - H04W 52/242: {taking into account path loss} - H04W 52/243: {taking into account interferences} - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04W 74/04: Scheduled access (hybrid access H04W74/02) - H04L 5/0007: {the frequencies being orthogonal, e.g. OFDM(A) or DMT} - H04W 74/006: {in the downlink, i.e. towards the terminal} - H04W 84/12: WLAN [Wireless Local Area Networks] - Y02D 30/70: in wireless communication networks - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract The present disclosure provides various aspects related to techniques for generating trigger frames, at an access point (AP), that reduce the overhead associated with triggering an uplink transmission from the wireless station (STA). Features of the present disclosure achieve this by, for example, utilizing a single per-user information field of the trigger to signal a plurality of random access resource units that may be allocated to the one or more STAs in the network. Such a technique is an improvement over the conventional system that require each random access resource unit to be signaled separately in a separate per-user information field (thus increasing the overhead). Additionally, aspects of the present disclosure allow the AP to effectively signal to the STA whether the one or more resources allocated to the at least one STA are a single user resource unit allocation or a multi-user resource unit allocation. ## Claims ### Claim 1 A method for wireless communications, comprising: determining, at an access point (AP), whether to trigger at least one station (STA) for uplink transmission; generating a trigger frame in response to a determination to trigger the at least one STA, wherein the trigger frame identifies whether one or more resources allocated to the at least one STA are a single user resource unit allocation or a multi-user resource unit allocation; setting, by the AP, a multi-user (MU) multiple-input and multiple-output (MIMO) long training field (LTF) mode subfield of the trigger frame based on whether the one or more resources allocated to the at least one STA are a single user resource unit allocation or a multi-user resource unit allocation; and transmitting the trigger frame to the at least one STA. ### Claim 2 (depends on 1) The method of claim 1, wherein the setting, by the AP, the MU MIMO LTF mode subfield comprises: setting, by the AP, the MU MIMO LTF mode subfield to a single-stream pilot based on a determination that at least one of the one or more resources allocated to the at least one STA is a single-user resource unit allocation. ### Claim 3 (depends on 1) The method of claim 1, wherein the setting, by the AP, the MU MIMO LTF mode subfield comprises: setting, by the AP, the MU MIMO LTF mode subfield to a masked LTF sequence or a single-pilot stream based on a determination that none of the one or more resources allocated to the at least one STA are a single-user resource unit allocation. ### Claim 4 (depends on 3) The method of claim 3, further comprising: identifying the MIMO LTF mode in a common information field of the trigger frame. ### Claim 5 (depends on 1) The method of claim 1, wherein the trigger frame further includes a per-user information field that identifies a plurality of random access resource units allocated to the at least one STA for uplink transmission. ### Claim 6 (depends on 1) The method of claim 1, further comprising: determining that one or more resources allocated to the at least one STA are for orthogonal frequency-division multiple access (OFDMA) backoff (OBO); allocating the one or more resources to association identifier (AID) value of zero; and receiving from the at least one STA a high efficiency (HE) trigger physical layer convergence procedure protocol data unit (HE_Trig PPDU) with a fixed basic service set (BSS) color information in response to the transmission of the trigger frame. ### Claim 7 An access point (AP) for wireless communications, comprising: a memory configured to store instructions for generating trigger frame; a processor communicatively coupled with the memory, the processor configured to execute the instructions to: determine, at the AP, whether to trigger at least one station (STA) for uplink transmission, and generate the trigger frame in response to a determination to trigger the at least one STA, wherein the trigger frame identifies whether one or more resources allocated to the at least one STA are a single user resource unit allocation or a multi-user resource unit allocation; set a multi-user (MU) multiple-input and multiple-output (MIMO) long training field (LTF) mode subfield of the trigger frame based on whether the one or more resources allocated to the at least one STA are a single user resource unit allocation or a multi-user resource unit allocation; and a transmitter configured to transmit the trigger frame to the at least one STA. ### Claim 8 (depends on 7) The AP of claim 7, wherein the processor is configured to set the MU MIMO LTF mode subfield by being configured to: set the MU MIMO LTF mode subfield to a single-stream pilot based on a determination that at least one of the one or more resources allocated to the at least one STA is a single-user resource unit allocation. ### Claim 9 (depends on 7) The AP of claim 7, wherein the processor is configured to set the MU MIMO LTF mode subfield by being configured to execute the instructions to: set the MU MIMO LTF mode subfield to a masked LTF sequence or a single-pilot stream based on a determination that none of the one or more resources allocated to the at least one STA are a single-user resource unit allocation. ### Claim 10 (depends on 9) The AP of claim 9, wherein the processor is further configured to execute the instructions to: identify the MIMO LTF mode in a common information field of the trigger frame. ### Claim 11 (depends on 7) The AP of claim 7, wherein the trigger frame further includes a per-user information field that identifies a plurality of random access resource units allocated to the at least one STA for uplink transmission. ### Claim 12 (depends on 7) The AP of claim 7, wherein the processor is further configured to execute the instructions to: determine that one or more resources allocated to the at least one STA are for orthogonal frequency-division multiple access (OFDMA) backoff (OBO); and allocate the one or more resources to association identifier (AID) value of zero, wherein the AP further comprises a receiver configured to receive from the at least one STA a high efficiency (HE) trigger physical layer convergence procedure protocol data unit (HE_Trig PPDU) with a fixed basic service set (BSS) color information in response to the transmission of the trigger frame. ### Claim 13 An apparatus for wireless communications, comprising: a memory; and at least one processor communicatively coupled with the memory and configured to: determine whether to trigger at least one station (STA) for uplink transmission, generate a trigger frame in response to a determination to trigger the at least one STA, wherein the trigger frame identifies whether one or more resources allocated to the at least one STA are a single user resource unit allocation or a multi-user resource unit allocation, set a multi-user (MU) multiple-input and multiple-output (MIMO) long training field (LTF) mode subfield of the trigger frame based on whether the one or more resources allocated to the at least one STA are a single user resource unit allocation or a multi-user resource unit allocation; and output the trigger frame for transmission to the at least one STA. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein the at least one processor is configured to set the MU MIMO LTF mode subfield of the trigger frame by being configured to: set the MU MIMO LTF mode subfield to a single-stream pilot based on a determination that at least one of the one or more resources allocated to the at least one STA is a single-user resource unit allocation. ### Claim 15 (depends on 13) The apparatus of claim 13, wherein the at least one processor is configured to set the MU MIMO LTF mode subfield of the trigger frame by being configured to: set the MU MIMO LTF mode subfield to a masked LTF sequence or a single-pilot stream based on a determination that none of the one or more resources allocated to the at least one STA are a single-user resource unit allocation. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein the at least one processor is further configured to: identify the MIMO LTF mode in a common information field of the trigger frame. ### Claim 17 (depends on 13) The apparatus of claim 13, wherein the trigger frame further includes a per-user information field that identifies a plurality of random access resource units allocated to the at least one STA for uplink transmission. ### Claim 18 (depends on 13) The apparatus of claim 13, wherein the at least one processor is further configured to: determine that one or more resources allocated to the at least one STA are for orthogonal frequency-division multiple access (OFDMA) backoff (OBO); allocate the one or more resources to an association identifier (AID) value of zero; and obtain, from the at least one STA, a high efficiency (HE) trigger physical layer convergence procedure protocol data unit (HE_Trig PPDU) with a fixed basic service set (BSS) color information in response to the trigger frame.