# US 11,445,329 B2 · Techniques for reducing uplink feedback latency for virtual reality devices in multi-user deployments > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,445,329 B2 - Document ID: US11445329B2 - Status: Granted - Kind: B2 - Application number: 17/165,486 - Filed: 2021-02-02 - Published: 2022-08-04 - Granted: 2022-09-13 - Earliest claimed: 2021-02-02 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Suresh Chandrasekaran; Parthiban Ellappan; Ravindra Chauhan - Web page: https://patentgrep.com/patent/US11445329B2 ## CPC - H04L 67/131: Protocols for games, networked simulations or virtual reality - H04W 4/027: {using movement velocity, acceleration information} - H04L 1/1864: {ARQ related signaling (H04L1/1607 takes precedence)} - H04L 65/61: for supporting one-way streaming services, e.g. Internet radio - H04L 65/70: Media network packetisation - H04N 5/38: Transmitter circuitry {for the transmission of television signals according to analogue transmission standards} (H04N5/14 takes precedence) - 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) - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Methods, systems, and devices for wireless communications are described. In some systems, a wireless station (STA), which may be an example of a virtual reality (VR) device, may receive downlink data or video frames from an access point (AP) for a display at the wireless STA. In some aspects, the wireless STA may detect a motion change of the wireless STA based on employing a motion change detection mechanism and, if the wireless STA detects a motion change, may transmit an indication of the motion change detection to the AP via a feedback message, such as a block acknowledgement (BA) feedback message. The wireless STA, based on detecting the motion change, may additionally transmit a set of inertial measurements of the wireless STA to the AP. The wireless STA may transmit the inertial measurements to the AP via the feedback message or a separate uplink message. ## Claims ### Claim 1 A method for wireless communication at a wireless station, comprising: receiving, from an access point, a first plurality of frames for an application of the wireless station; detecting a motion change of the wireless station; transmitting, to the access point: a feedback message including acknowledgement information associated with each of the first plurality of frames and indicating that the motion change is detected and a set of inertial measurements associated with the wireless station based at least in part on detecting the motion change of the wireless station; and receiving, from the access point, a second plurality of frames for the application of the wireless station based at least in part on the feedback message indicating that the motion change is detected and the set of inertial measurements associated with the wireless station. ### Claim 2 (depends on 1) The method of claim 1, wherein detecting the motion change of the wireless station further comprises: comparing a first set of inertial measurements from a first time period with the set of inertial measurements from a second time period to obtain a difference in inertial measurements between the first time period and the second time period; and determining that the difference in inertial measurements satisfies a motion change detection threshold. ### Claim 3 (depends on 1) The method of claim 1, wherein transmitting the set of inertial measurements associated with the wireless station further comprises: transmitting an indication of the set of inertial measurements associated with the wireless station within a block acknowledgement information field of the feedback message. ### Claim 4 (depends on 3) The method of claim 3, wherein transmitting the feedback message indicating that the motion change is detected further comprises: transmitting an indication that the block acknowledgement information field includes the set of inertial measurements associated with the wireless station via a bit within a block acknowledgement control field of the feedback message. ### Claim 5 (depends on 1) The method of claim 1, wherein transmitting the feedback message indicating that the motion change is detected further comprises: transmitting an indication that the motion change is detected via a bit in the feedback message during a first time period. ### Claim 6 (depends on 5) The method of claim 5, wherein transmitting the set of inertial measurements associated with the wireless station further comprises: transmitting an uplink message including the set of inertial measurements associated with the wireless station during a second time period based at least in part on transmitting the indication that the motion change is detected via the bit in the feedback message during the first time period. ### Claim 7 (depends on 6) The method of claim 6, wherein there is an absence of downlink data between the first time period and the second time period based at least in part on transmitting the indication that the motion change is detected during the first time period. ### Claim 8 (depends on 1) The method of claim 1, wherein receiving the first plurality of frames for the application of the wireless station further comprises: receiving a plurality of video frames for a virtual reality application of the wireless station. ### Claim 9 A method for wireless communication at an access point, comprising: transmitting, to a wireless station, a first plurality of frames for an application of the wireless station; receiving, from the wireless station: a feedback message including acknowledgement information associated with each of the first plurality of frames and indicating that a motion change of the wireless station is detected and a set of inertial measurements associated with the wireless station based at least in part on the indicating that the motion change of the wireless station is detected; and transmitting, to the wireless station, a second plurality of frames for the application of the wireless station based at least in part on the feedback message indicating that the motion change is detected. ### Claim 10 (depends on 9) The method of claim 9, wherein receiving the set of inertial measurements associated with the wireless station further comprises: receiving an indication of the set of inertial measurements associated with the wireless station within a block acknowledgement information field of the feedback message. ### Claim 11 (depends on 10) The method of claim 10, wherein receiving the feedback message indicating that the motion change is detected further comprises: receiving an indication that the block acknowledgement information field includes the set of inertial measurements associated with the wireless station via a bit within a block acknowledgement control field of the feedback message. ### Claim 12 (depends on 9) The method of claim 9, wherein receiving the feedback message indicating that the motion change is detected further comprises: receiving an indication that the motion change is detected via a bit in the feedback message during a first time period. ### Claim 13 (depends on 12) The method of claim 12, wherein receiving the set of inertial measurements associated with the wireless station further comprises: receiving, from the wireless station, an uplink message including the set of inertial measurements associated with the wireless station during a second time period based at least in part on receiving the indication that the motion change is detected via the bit in the feedback message during the first time period. ### Claim 14 (depends on 13) The method of claim 13, further comprising: refraining from transmitting downlink data between the first time period and the second time period based at least in part on receiving the indication that the motion change is detected during the first time period and receiving the uplink message including the set of inertial measurements associated with the wireless station during the second time period. ### Claim 15 (depends on 9) The method of claim 9, wherein transmitting the first plurality of frames for the application of the wireless station further comprises: transmitting a plurality of video frames for a virtual reality application of the wireless station. ### Claim 16 (depends on 9) The method of claim 9, wherein the access point operates in a multi-user virtual reality scenario, the method further comprising: transmitting, to a plurality of wireless stations, a first plurality of video frames for virtual reality applications of the plurality of wireless stations; receiving, from one or more wireless stations of the plurality of wireless stations: feedback messages responsive to the first plurality of video frames and indicating that respective motion changes of the one or more wireless stations are detected and sets of inertial measurements associated with the one or more wireless stations based at least in part on the indicating that the respective motion changes of the one or more wireless stations are detected; and transmitting, to the one or more wireless stations, a second plurality of video frames for the virtual reality applications of the one or more wireless stations based at least in part on the feedback messages indicating that the respective motion changes are detected. ### Claim 17 An apparatus for wireless communication at a wireless station, comprising: a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to: receive, from an access point, a first plurality of frames for an application of the wireless station; detect a motion change of the wireless station; transmit, to the access point: a feedback message including acknowledgement information associated with each of the first plurality of frames and indicating that the motion change is detected and a set of inertial measurements associated with the wireless station based at least in part on detecting the motion change of the wireless station; and receive, from the access point, a second plurality of frames for the application of the wireless station based at least in part on the feedback message indicating that the motion change is detected and the set of inertial measurements associated with the wireless station. ### Claim 18 (depends on 17) The apparatus of claim 17, wherein the instructions to detect the motion change of the wireless station are further executable by the processor to cause the apparatus to: compare a first set of inertial measurements from a first time period with the set of inertial measurements from a second time period to obtain a difference in inertial measurements between the first time period and the second time period; and determine that the difference in inertial measurements satisfies a motion change detection threshold. ### Claim 19 (depends on 17) The apparatus of claim 17, wherein the instructions to transmit the set of inertial measurements associated with the wireless station are further executable by the processor to cause the apparatus to: transmit an indication of the set of inertial measurements associated with the wireless station within a block acknowledgement information field of the feedback message. ### Claim 20 (depends on 19) The apparatus of claim 19, wherein the instructions to transmit the feedback message indicating that the motion change is detected are further executable by the processor to cause the apparatus to: transmit an indication that the block acknowledgement information field includes the set of inertial measurements associated with the wireless station via a bit within a block acknowledgement control field of the feedback message. ### Claim 21 (depends on 17) The apparatus of claim 17, wherein the instructions to transmit the feedback message indicating that the motion change is detected are further executable by the processor to cause the apparatus to: transmit an indication that the motion change is detected via a bit in the feedback message during a first time period. ### Claim 22 (depends on 21) The apparatus of claim 21, wherein the instructions to transmit the set of inertial measurements associated with the wireless station are further executable by the processor to cause the apparatus to: transmit an uplink message including the set of inertial measurements associated with the wireless station during a second time period based at least in part on transmitting the indication that the motion change is detected via the bit in the feedback message during the first time period. ### Claim 23 (depends on 22) The apparatus of claim 22, wherein there is an absence of downlink data between the first time period and the second time period based at least in part on transmitting the indication that the motion change is detected during the first time period. ### Claim 24 An apparatus for wireless communication at an access point, comprising: a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to: transmit, to a wireless station, a first plurality of frames for an application of the wireless station; receive, from the wireless station: a feedback message including acknowledgement information associated with each of the first plurality of frames and indicating that a motion change of the wireless station is detected and a set of inertial measurements associated with the wireless station based at least in part on the indicating that the motion change of the wireless station is detected; and transmit, to the wireless station, a second plurality of frames for the application of the wireless station based at least in part on the feedback message indicating that the motion change is detected. ### Claim 25 (depends on 24) The apparatus of claim 24, wherein the instructions to receive the set of inertial measurements associated with the wireless station are further executable by the processor to cause the apparatus to: receive an indication of the set of inertial measurements associated with the wireless station within a block acknowledgement information field of the feedback message. ### Claim 26 (depends on 25) The apparatus of claim 25, wherein the instructions to receive the feedback message indicating that the motion change is detected are further executable by the processor to cause the apparatus to: receive an indication that the block acknowledgement information field includes the set of inertial measurements associated with the wireless station via a bit within a block acknowledgement control field of the feedback message. ### Claim 27 (depends on 24) The apparatus of claim 24, wherein the instructions to receive the feedback message indicating that the motion change is detected are further executable by the processor to cause the apparatus to: receive an indication that the motion change is detected via a bit in the feedback message during a first time period. ### Claim 28 (depends on 27) The apparatus of claim 27, wherein the instructions to receive the set of inertial measurements associated with the wireless station are further executable by the processor to cause the apparatus to: receive, from the wireless station, an uplink message including the set of inertial measurements associated with the wireless station during a second time period based at least in part on receiving the indication that the motion change is detected via the bit in the feedback message during the first time period. ### Claim 29 (depends on 28) The apparatus of claim 28, wherein the instructions are further executable by the processor to cause the apparatus to: refrain from transmitting downlink data between the first time period and the second time period based at least in part on receiving the indication that the motion change is detected during the first time period and receiving the uplink message including the set of inertial measurements associated with the wireless station during the second time period. ### Claim 30 (depends on 24) The apparatus of claim 24, wherein the access point operates in a multi-user virtual reality scenario, and the instructions are further executable by the processor to cause the apparatus to: transmit, to a plurality of wireless stations, a first plurality of video frames for virtual reality applications of the plurality of wireless stations; receive, from one or more wireless stations of the plurality of wireless stations: feedback messages responsive to the first plurality of video frames and indicating that respective motion changes of the one or more wireless stations are detected and sets of inertial measurements associated with the one or more wireless stations based at least in part on the indicating that the respective motion changes of the one or more wireless stations are detected; and transmit, to the one or more wireless stations, a second plurality of video frames for the virtual reality applications of the one or more wireless stations based at least in part on the feedback messages indicating that the respective motion changes are detected.