# US 11,115,925 B2 · Power saving mechanism for MU-MIMO transmissions > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,115,925 B2 - Document ID: US11115925B2 - Status: Granted - Kind: B2 - Application number: 16/786,638 - Filed: 2020-02-10 - Published: 2020-11-12 - Granted: 2021-09-07 - Earliest claimed: 2016-12-23 - Assignees: Intel Corporation - Applicants: Intel Corporation - Inventors: Ou Yang; Carlos Cordeiro; Laurent Cariou; Chittabrata Ghosh; Solomon Trainin - Web page: https://patentgrep.com/patent/US11115925B2 ## CPC - H04W 52/0216: {using a pre-established activity schedule, e.g. traffic indication frame} - H04B 7/0452: Multi-user MIMO systems - H04W 52/0219: {where the power saving management affects multiple terminals} - 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) - H04B: TRANSMISSION - 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 Techniques for power saving by remote wireless mobile devices are provided, in particular by stations (STAs) during downlink (DL) multiple-user multiple-input and multiple-output (MU-MIMO) transmissions in an Institute of Electrical and Electronics Engineers (IEEE) 802.11ay network when reverse direction (RD) transmissions are either enabled and not enabled. Various embodiments enable each STA in a group of STAs to determine an order in which the STAs are requested to send a block acknowledgement (BACK) and which STAs will be granted an RD transmission. Further, a duration of each RD transmission is provided to each STA. Based on the provided information, each STA can determine times to enter a power saving mode. Other embodiments are described and claimed. ## Claims ### Claim 1 An apparatus, comprising: a memory of a first station (STA); and processing circuitry of the first STA coupled to the memory, the processing circuitry to: process a first multiple-user PHY protocol data unit (MU-PPDU) communicated in a downlink (DL) multiple-user multiple-input and multiple-output (MU-MIMO) communication to initiate a reverse direction communication; cause transmission of the reverse direction communication including a first block acknowledgement and data in response to reception of the first MU-PPDU; cause the first STA to be in a power save state between the first block acknowledgement until receipt of a second MU-MIMO PPDU including a second aggregate medium access control (MAC) protocol data unit (A-MPDU); and process a second block acknowledgement communicated to acknowledge the reverse direction communication. ### Claim 2 (depends on 1) The apparatus of claim 1, the first MU-PPDU comprising a bit of a reverse direction (RD) indication set to 1 to initiate a reverse direction communication. ### Claim 3 (depends on 1) The apparatus of claim 1, the first MU-PPDU comprising a Response Duration for a reverse direction (RD) responder. ### Claim 4 (depends on 1) The apparatus of claim 1, the first MU-PPDU comprising a request for a block acknowledgement frame to initiate a reverse direction communication. ### Claim 5 (depends on 1) The apparatus of claim 1, the first MU-PPDU comprising a quality of service (QoS) frame to initiate a reverse direction communication. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein a block acknowledgement request frame and a QoS Null frame are aggregated in a MAC protocol data unit (MPDU) of the MU-PPDU. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the MU-PPDU is received from one of an access point (AP) and personal basic service set (PBSS) control point (PCP). ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the first STA is one of a plurality of STAs in a MU-MIMO group. ### Claim 9 (depends on 1) The apparatus of claim 1, comprising: a transceiver; and one or more antennas coupled with the transceiver. ### Claim 10 (depends on 9) The apparatus of claim 9, the processing circuitry to cause transmission of the reverse direction communication to one of an access point (AP) and a personal basic service set (PBSS) control point (PCP) via the transceiver and one or more antennas. ### Claim 11 A non-transitory computer-readable storage medium, comprising a plurality of instructions, that when executed, enable processing circuitry to: process a first multiple-user PHY protocol data unit (MU-PPDU) communicated in a downlink (DL) multiple-user multiple-input and multiple-output (MU-MIMO) communication to initiate a reverse direction communication; cause transmission of the reverse direction communication including a first block acknowledgement and data in response to reception of the first MU-PPDU; cause a first STA to be in a power save state between the first block acknowledgement until receipt of a second MU-MIMO PPDU including a second aggregate medium access control (MAC) protocol data unit (A-MPDU); and process a second block acknowledgement communicated to acknowledge the reverse direction communication. ### Claim 12 (depends on 11) The non-transitory computer-readable storage medium of claim 11, the first MU-PPDU comprising a bit of a reverse direction (RD) indication set to 1 to initiate a reverse direction communication. ### Claim 13 (depends on 11) The non-transitory computer-readable storage medium of claim 11, the first MU-PPDU comprising a Response Duration for a reverse direction (RD) responder. ### Claim 14 (depends on 11) The non-transitory computer-readable storage medium of claim 11, the first MU-PPDU comprising a request for a block acknowledgement frame to initiate a reverse direction communication. ### Claim 15 (depends on 11) The non-transitory computer-readable storage medium of claim 11, the first MU-PPDU comprising a quality of service (QoS) frame to initiate a reverse direction communication. ### Claim 16 A computer-implemented method, comprising: processing a first multiple-user PHY protocol data unit (MU-PPDU) communicated in a downlink (DL) multiple-user multiple-input and multiple-output (MU-MIMO) communication to initiate a reverse direction communication; causing transmission of the reverse direction communication including a first block acknowledgement and data in response to reception of the first MU-PPDU; causing the a STA to be in a power save state between the first block acknowledgement until receipt of a second MU-MIMO PPDU including a second aggregate medium access control (MAC) protocol data unit (A-MPDU); and processing a second block acknowledgement communicated to acknowledge the reverse direction communication. ### Claim 17 (depends on 16) The computer-implemented method of claim 16, the first MU-PPDU comprising a bit of a reverse direction (RD) indication set to 1 to initiate a reverse direction communication. ### Claim 18 (depends on 16) The computer-implemented method of claim 16, the first MU-PPDU comprising a Response Duration for a reverse direction (RD) responder. ### Claim 19 (depends on 16) The computer-implemented method of claim 16, the first MU-PPDU comprising a request for a block acknowledgement frame to initiate a reverse direction communication. ### Claim 20 (depends on 16) The computer-implemented method of claim 16, the first MU-PPDU comprising a quality of service (QoS) frame to initiate a reverse direction communication. ### Claim 21 (depends on 16) The computer-implemented method of claim 16, comprising causing transmission of the reverse direction communication to one of an access point (AP) and personal basic service set (PBSS) control point (PCP) via a transceiver coupled one or more antennas.