# US 11,445,545 B2 · Full duplex opportunity discovery and transmission for asymmetric full duplex wireless local area networks (WLANs) > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,445,545 B2 - Document ID: US11445545B2 - Status: Granted - Kind: B2 - Application number: 17/052,642 - Filed: 2019-05-03 - Published: 2021-08-05 - Granted: 2022-09-13 - Earliest claimed: 2018-05-03 - Assignees: InterDigital Patent Holdings, Inc. - Applicants: Interdigital Patent Holdings, Inc. - Inventors: Oghenekome Oteri; Guodong Zhang; Li-Hsiang Sun; Robert L. Olesen - Web page: https://patentgrep.com/patent/US11445545B2 ## CPC - H04W 74/02: Hybrid access - H04W 74/0816: with collision avoidance - H04L 5/0037: {Inter-user or inter-terminal allocation} - 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 5/0092: {Indication of how the channel is divided} - H04L 5/14: Two-way operation using the same type of signal, i.e. duplex - H04W 24/10: Scheduling measurement reports {; Arrangements for measurement reports} - H04W 74/00: Wireless channel access - H04W 84/12: WLAN [Wireless Local Area 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) ## Abstract Methods and apparatuses are described herein for full-duplex transmission opportunity discovery and transmission in a wireless 802.11 network A full duplex compatible access point may transmit a full duplex (FD) transmission opportunity (TxOP) setup frame to a plurality of wireless transmit/receive units (WTRUs). This enables each of the plurality of WTRUs to transmit a measurement frame for interference measurement by the each of the other WTRUs to determine which WTRUs may participate in FD communication. Feedback is received by the AP and the AP determines which of the plurality of WTRUs the AP can perform FD communication with based on the feedback. FD communication with the determined WTRUs is then commenced. ## Claims ### Claim 1 A method for use in an IEEE 802.11 access point (AP), the method comprising: transmitting a transmission opportunity (TxOP) setup frame to a plurality of stations (STAs) including information enabling each of the plurality of STAs to transmit a measurement frame; receiving feedback from each of the plurality of STAs following the measurement frames transmitted by the plurality of STAs; determining which of the plurality of STAs the AP can communicate with during a TxOP based on the feedback; transmitting a trigger frame to the determined STAs to communicate during the TxOP; transmitting, during the TxOP, downlink data to a first STA of the determined STAs and receiving, during the TxOP, uplink data from a second STA of the determined STAs, wherein the transmission of the downlink data to the first STA overlaps in time with the reception of uplink data from the second STA. ### Claim 2 (depends on 1) The method of claim 1, wherein the trigger frame transmitted to the determined STAs enables each of the determined STAs to transmit a clear to send (CTS) frame that enables each of the determined STAs to perform an interference measurement of each CTS to confirm the TxOP is acceptable. ### Claim 3 (depends on 1) The method of claim 1, further comprising: transmitting a poll frame to the plurality of STAs, wherein feedback received from each of to elicit the plurality of STAs is received in response to the transmitted poll frame. ### Claim 4 (depends on 3) The method of claim 3, wherein the feedback that is received from each of the plurality of STAs is received in a same sequence as a sequence of the measurement frames transmitted by each of the plurality of STAs. ### Claim 5 (depends on 1) The method of claim 1, further comprising: transmitting a multi-user (MU) trigger frame to the plurality of STAs; and receiving, in response to the transmitted MU trigger frame, feedback from each of the plurality of STAs. ### Claim 6 (depends on 5) The method of claim 5, wherein the feedback that is received from each of the plurality of STAs is received in MU transmissions from each of the plurality of STAs. ### Claim 7 An IEEE 802.11 access point (AP) comprising: a transmitter configured to transmit a transmission opportunity (TxOP) setup frame to a plurality of stations (STAs) including information enabling each of the plurality of STAs to transmit a measurement frame; a receiver configured to receive feedback from each of the plurality STAs following the measurement frames transmitted by the plurality of STAs; and a processor configured to determine which of the plurality of STAs the AP can communicate with during a TxOP based on the feedback; wherein the transmitter is further configured to transmit a trigger frame to the determined STAs to communicate during the TxOP; and wherein the transmitter and the receiver are configured to transmit, during the TxOP, downlink data to a first STA of the determined STAs and receive uplink data from a second STA of the determined STAs, wherein the transmission of the downlink data to the first STA overlaps in time with the reception of uplink data from the second STA. ### Claim 8 (depends on 7) The AP of claim 7, wherein the trigger frame transmitted to the determined STAs enables each of the determined STAs to transmit a clear to send (CTS) frame that enables each of the determined STAs to perform an interference measurement of each CTS to confirm that the TxOP is acceptable. ### Claim 9 (depends on 7) The AP of claim 7, wherein the transmitter is configured to transmit a poll frame to the plurality of STAs, wherein feedback received from each of the plurality of STAs is received in response to the transmitted poll frame. ### Claim 10 (depends on 9) The AP of claim 9, wherein the feedback that is received from each of the plurality of STAs is received in a same sequence as a sequence of the measurement frames transmitted by each of the plurality of STAs. ### Claim 11 (depends on 8) The AP of claim 8, wherein the transmitter is configured to transmit a multi-user (MU) trigger frame to the plurality of STAs; and wherein the receiver is configured to, in response to the transmitted MU trigger frame, receive feedback from each of the plurality of STAs. ### Claim 12 (depends on 11) The AP of claim 11, wherein the feedback that is received from each of the plurality of STAs is received in MU transmissions from each the plurality of STAs.