# US 2021/0344451 A1 · Efficient and robust acknowledgement procedures for new radio operation in unlicensed bands > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0344451 A1 - Document ID: US20210344451A1 - Status: Published application - Kind: A1 - Application number: 17/266,785 - Filed: 2019-08-08 - Published: 2021-11-04 - Earliest claimed: 2018-08-08 - Assignees: IDAC Holdings, Inc. - Applicants: Idac Holdings, Inc. - Inventors: Ahmad Reza Hedayat; Shahrokh Nayeb Nazar; Oghenekome Oteri; Hanqing Lou; Rui Yang - Web page: https://patentgrep.com/patent/US20210344451A1 ## CPC - H04L 1/1819: {with retransmission of additional or different redundancy} - H04L 1/1861: {Physical mapping arrangements (for ACK signaling see also H04L5/0053)} - H04L 1/1854: {Scheduling and prioritising arrangements} - H04L 1/1896: {ARQ related signaling} - H04L 5/0055: {Physical resource allocation for ACK/NACK (for physical mapping arrangements in ARQ protocols H04L1/1861)} - H04W 72/0446: Resources in time domain, e.g. slots or frames - H04W 74/002: {Transmission of channel access control information} - H04W 74/0816: with collision avoidance - H04L 1/1614: {using bitmaps} - 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) ## Abstract Systems, methods, and devices for efficient and robust handling of acknowledgements in new radio unlicensed bands (NR-U) environments. A wireless transmit receive unit (WTRU) may receive control information and a data transmission from a gNB in a first interval (i.e., transport block or channel occupancy time), wherein the control information may include an indication of uplink resources. The data transmission may require some sort of acknowledgement (i.e., HARQ feedback). The WTRU may attempt to transmit the acknowledgement in the indicated uplink resources, but the gNB may not receive the acknowledgement. The WTRU may receive control information and a data transmission from the gNB in a second interval, including an indication to aggregate any previously unsuccessful acknowledgement transmissions. The WTRU may transmit an aggregated acknowledgement including previous unsuccessful acknowledgements and any additional acknowledgements from the current interval. In some cases, look-before-talk procedures may be used. ## Claims ### Claim at position 1 -14. (canceled) ### Claim 1 A method implemented by a wireless transmit receive unit (WTRU), the method comprising: receiving first control information for a first physical downlink shared channel (PDSCH) transmission on a first physical downlink control channel (PDCCH), and wherein the first control information further includes a first HARQ feedback timing indicator; determining not to send a first HARQ feedback for the first PDSCH transmission based on a value of the first HARQ feedback timing indicator; receiving second control information for a second PDSCH transmission on a second PDCCH; and sending HARQ feedback that includes the first HARQ feedback for the first PDSCH transmission combined with a second HARQ feedback for the second PDSCH transmission based on the second control information. ### Claim 2 (depends on 1) The method of claim 1, wherein the second control information includes a second HARQ feedback timing indicator. ### Claim 3 (depends on 1) The method of claim 1, where the HARQ feedback for the first and second PDSCH transmissions are sent based on timing indicated by a second HARQ feedback timing indicator ### Claim 4 (depends on 1) The method of claim 1, wherein the HARQ feedback for the first and second PDSCH transmissions are sent on a Physical Uplink Control Channel (PUCCH) resource indicated in the second control information. ### Claim 5 (depends on 1) The method of claim 1, wherein the first HARQ feedback timing indicator is a first PDSCH-to-HARQ timing indicator and a second HARQ feedback timing indicator is a second PDSCH-to-HARQ timing indicator. ### Claim 6 (depends on 1) The method of claim 1, wherein the second control information includes an indication of a group of PDSCH transmissions to include in the HARQ feedback, wherein the group of PDSCHs includes the first PDSCH transmission and the second PDSCH transmission. ### Claim 7 (depends on 1) The method of claim 1, further comprising performing a listen-before-talk (LBT) prior to sending the HARQ feedback. ### Claim 8 A wireless transmit receive unit (WTRU), the WTRU comprising: a processor operatively coupled to a transceiver; the transceiver configured to receive first control information for a first physical downlink shared channel (PDSCH) transmission on a first physical downlink control channel (PDCCH), and wherein the first control information further includes a first HARQ feedback timing indicator; the processor configured to determine not to send a first HARQ feedback for the first PDSCH transmission based on a value of the first HARQ feedback timing indicator; the transceiver configured to receive second control information for a second PDSCH transmission on a second PDCCH; and the transceiver configured to send HARQ feedback that includes the first HARQ feedback for the first PDSCH transmission combined with a second HARQ feedback for the second PDSCH transmission based on the second control information. ### Claim 9 (depends on 8) The WTRU of claim 8, wherein the second control information includes a second HARQ feedback timing indicator. ### Claim 10 (depends on 8) The WTRU of claim 8, where the HARQ feedback for the first and second PDSCH transmissions are sent based on timing indicated by a second HARQ feedback timing indicator ### Claim 11 (depends on 8) The WTRU of claim 8, wherein the HARQ feedback for the first and second PDSCH transmissions are sent on a Physical Uplink Control Channel (PUCCH) resource indicated in the second control information. ### Claim 12 (depends on 8) The WTRU of claim 8, wherein the first HARQ feedback timing indicator is a first PDSCH-to-HARQ timing indicator and a second HARQ feedback timing indicator is a second PDSCH-to-HARQ timing indicator. ### Claim 13 (depends on 8) The WTRU of claim 8, wherein the second control information includes an indication of a group of PDSCH transmissions to include in the HARQ feedback, wherein the group of PDSCHs includes the first PDSCH transmission and the second PDSCH transmission. ### Claim 14 (depends on 8) The WTRU of claim 8, the processor and transceiver configured to perform a listen-before-talk (LBT) prior to sending the HARQ feedback.