# US 11,310,693 B2 · Switching scheme for opting in and out of multi-user orthogonal frequency-division multiple access > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,310,693 B2 - Document ID: US11310693B2 - Status: Granted - Kind: B2 - Application number: 16/713,956 - Filed: 2019-12-13 - Published: 2021-06-17 - Granted: 2022-04-19 - Earliest claimed: 2019-12-13 - Assignees: Google Inc. - Applicants: Google LLC - Inventors: Ahmed Ibrahim ElArabawy; Ning Zhang; Kai Shi - Web page: https://patentgrep.com/patent/US11310693B2 ## CPC - H04L 1/0035: {evaluation of received explicit signalling} - H04W 48/06: based on traffic conditions - H04B 7/0452: Multi-user MIMO systems - H04B 7/0689: {using different transmission schemes, at least one of them being a diversity transmission scheme} - H04L 5/0007: {the frequencies being orthogonal, e.g. OFDM(A) or DMT} - H04L 5/0037: {Inter-user or inter-terminal allocation} - H04L 5/0055: {Physical resource allocation for ACK/NACK (for physical mapping arrangements in ARQ protocols H04L1/1861)} - H04L 27/0008: {arrangements for allowing a transmitter or receiver to use more than one type of modulation (negotiating modulation type for two-way transmission paths H04L5/1453)} - H04L 27/2602: {Signal structure} - H04W 28/0289: {Congestion control (load shedding arrangements in network planning H04W16/08; performing reselection for handling the traffic H04W36/22; wireless traffic scheduling H04W72/12)} - H04W 28/06: Optimizing {the usage of the radio link}, e.g. header compression, information sizing {, discarding information (system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365)} - H04W 72/0453: Resources in frequency domain, e.g. a carrier in FDMA - H04L 1/0003: {by switching between different modulation schemes} - H04W 72/21: in the uplink direction of a wireless link, i.e. towards the network - H04W 84/12: WLAN [Wireless Local Area Networks] - 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) - H04B: TRANSMISSION ## Abstract This document describes methods, devices, systems, and means for a switching scheme for opting in and out of multi-user orthogonal frequency-division multiple access (MU-OFDMA). In one aspect, an electronic device enters the MU-OFDMA mode to communicate via a wireless network over a shared-channel bandwidth. During the MU-OFDMA mode, the electronic device determines that an uplink-queue size is greater than a first threshold size. Responsive to the determining, the electronic device opts out of the MU-OFDMA mode and enters a single-user mode to contend for a transmit channel for transmitting uplink data. ## Claims ### Claim 1 A method performed by an electronic device, the method comprising: entering a multi-user orthogonal frequency-division multiple access (MU-OFDMA) mode to communicate via a wireless network over a shared-channel bandwidth; responsive to entering the MU-OFDMA mode, initiating a first timer that defines an amount of time in which the electronic device is prevented from opting out of the MU-OFDMA mode; during the MU-OFDMA mode, determining that an uplink-queue size is greater than a first threshold size; and responsive to the determining and expiration of the first timer: opting out of the MU-OFDMA mode; and entering a single-user mode to contend for a transmit channel for transmitting uplink data. ### Claim 2 (depends on 1) The method of claim 1, wherein the opting out comprises: transmitting, to an access point of the wireless network, an indication to disable the MU-OFDMA mode; and receiving an acknowledgment signal from the access point indicating that the MU-OFDMA mode is disabled for the electronic device. ### Claim 3 (depends on 1) The method of claim 1, further comprising: subsequent to entering the single-user mode, determining that the uplink-queue size has decreased to a size that is less than a second threshold size; and responsive to the determining that the uplink-queue size has decreased to a size that is less than the second threshold, opting in to the MU-OFDMA mode. ### Claim 4 (depends on 3) The method of claim 3, wherein the opting in to the MU-OFDMA mode includes: transmitting a request to an access point of the wireless network to participate in the MU-OFDMA mode; receiving an additional acknowledgment signal to enter the MU-OFDMA mode; and re-entering the MU-OFDMA mode. ### Claim 5 (depends on 3) The method of claim 3, further comprising: initiating a second timer in response to entering the single-user mode; and delaying the opting in to the MU-OFDMA mode until expiration of the second timer. ### Claim 6 (depends on 3) The method of claim 3, further comprising: initiating a second timer in response to entering the single-user mode; and delaying the determining of uplink-queue size being less than a second threshold size until after the second timer expires. ### Claim 7 (depends on 3) The method of claim 3, wherein the determining of uplink-queue size being less than a second threshold size comprises determining that the uplink-queue size has decreased below a third threshold size that is less than the second threshold size. ### Claim 8 (depends on 3) The method of claim 3, wherein the first and second thresholds are based on an access category of the uplink data. ### Claim 9 (depends on 3) The method of claim 3, wherein at least one of the first threshold or the second threshold is dependent on a maximum latency in an uplink queue. ### Claim 10 (depends on 1) The method of claim 1, further comprising: waiting until the first timer expires before performing the determining of the uplink-queue size being greater than the first threshold size. ### Claim 11 An electronic device comprising: a memory and a processor, the processor configured to execute instructions stored in the memory to implement an access-mode manager application configured to: manage transmission and reception of signals over a wireless network according to a multi-user orthogonal frequency-division multiple access (MU-OFDMA) mode; enter the MU-OFDMA mode to communicate via a wireless network over a shared-channel bandwidth; responsive to entering the MU-OFDMA mode, initiate a first timer that defines an amount of time in which the electronic device is prevented from opting out of the MU-OFDMA mode; during the MU-OFDMA mode, determine that an uplink-queue size is greater than a first threshold size; responsive to a determination that the uplink-queue size is greater than the first threshold size and expiration of the first timer: opt out of the MU-OFDMA mode; and enter a single-user mode to contend for a transmit channel for transmitting uplink data. ### Claim 12 (depends on 11) The electronic device of claim 11, wherein to opt out of the MU-OFDMA mode, the access-mode manager application is configured to: transmit, to an access point of the wireless network, an indication to disable the MU-OFDMA mode; and receive an acknowledgment signal from the access point indicating that the MU-OFDMA mode is disabled for the electronic device. ### Claim 13 (depends on 11) The electronic device of claim 11, wherein the access-mode manager application is further configured to: subsequent to entering the single-user mode, determine whether the uplink-queue size has decreased to a size that is less than a second threshold size; and responsive to a determination that the uplink-queue size has decreased to a size that is less than the second threshold, opt in to the MU-OFDMA mode. ### Claim 14 (depends on 13) The electronic device of claim 13, wherein to opt in to the MU-OFDMA mode, the access-mode manager application is configured to: transmit a request to an access point of the wireless network to participate in the MU-OFDMA mode; receive an additional acknowledgment signal to enter the MU-OFDMA mode; and re-enter the MU-OFDMA mode. ### Claim 15 (depends on 13) The electronic device of claim 13, wherein the access-mode manager application is further configured to: initiate a second timer in response to entering the single-user mode; and delay the opting in to the MU-OFDMA mode until expiration of the second timer. ### Claim 16 (depends on 13) The electronic device of claim 13, wherein the access-mode manager application is further configured to: initiate a second timer in response to entering the single-user mode; and delay the determination of whether the uplink-queue size has decreased to a size that is less than a second threshold size until after the second timer expires. ### Claim 17 (depends on 13) The electronic device of claim 13, wherein to determine whether the uplink-queue size has decreased to a size that is less than a second threshold size includes a determination that the uplink-queue size has decreased below a third threshold size that is less than the second threshold size. ### Claim 18 (depends on 13) The electronic device of claim 13, wherein the first and second thresholds are based on an access category of the uplink data. ### Claim 19 (depends on 13) The electronic device of claim 13, wherein at least one of the first threshold or the second threshold is dependent on a maximum latency in an uplink queue. ### Claim 20 (depends on 11) The electronic device of claim 11, wherein the access-mode manager application is further configured to wait until the first timer expires before making the determination of the uplink-queue size being greater than the first threshold size.