# US 2019/0357222 A1 · Collision mitigation procedures for grant-less uplink multiple access > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0357222 A1 - Document ID: US20190357222A1 - Status: Published application - Kind: A1 - Application number: 16/475,818 - Filed: 2018-01-05 - Published: 2019-11-21 - Earliest claimed: 2017-01-06 - Assignees: IDAC Holdings, Inc. - Applicants: Idac Holdings, Inc. - Inventors: Hanqing Lou; Xiaofei Wang; Rui Yang; Mihaela C. Beluri; Janet A. Stern-Berkowitz - Web page: https://patentgrep.com/patent/US20190357222A1 ## CPC - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04W 72/541: using the level of interference - H04L 5/0055: {Physical resource allocation for ACK/NACK (for physical mapping arrangements in ARQ protocols H04L1/1861)} - H04W 4/70: Services for machine-to-machine communication [M2M] or machine type communication [MTC] - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04W 74/085: {collision avoidance} - H04W 72/02: Selection of wireless resources by user or terminal - H04W 72/115: Grant-free or autonomous transmission - H04W 74/0836: with 2-step access - H04W 74/0838: using contention-free random access [CFRA] - 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 A wireless transmit/receive unit (WTRU) may receive a grant-less (GL) transmission configuration that may include a first indication of a first set of resource blocks (RBs) for a first resource pool and a second indication of a second set of RBs for a second resource pool. The WTRU may select a subset of RBs in the first set, determine a subset of RBs in the second set based on the selected subset of RBs in the first set, and transmit UL data to the base station via the determined subset of RBs in the second set. The WTRU may receive a negative acknowledgement (NAK) with a third indication for at least one of a first transmission failure reason and a second transmission reason. The WTRU may adjust a backoff and determine a retransmission scheme based on the received third indication, and retransmit the UL data. ## Claims ### Claim 1 A wireless transmit/receive unit (WTRU) for grant-less (GL) uplink (UL) transmissions, the WTRU comprising: a transceiver configured to receive one or more GL transmission configurations, including a first indication of a first set of resource blocks (RBs) for a first resource pool, and a second indication of a second set of RBs for a second resource pool; a processor operatively coupled to the transceiver, the processor configured to select a subset of RBs in the first set; the processor configured to determine a subset of RBs in the second set based on the selected subset of RBs in the first set; the processor and the transceiver configured to transmit UL data, via the determined subset of RBs in the second set, to a base station; the transceiver configured to receive a negative acknowledgement (NAK) with a third indication for at least one of a first transmission failure reason and a second transmission failure reason, wherein the first transmission failure reason is due to UL collision and the second transmission failure reason is due to UL low Signal-to-Noise Ratio (SNR); the processor configured to adjust a backoff and determine a retransmission scheme based on the received third indication, wherein on a condition that the third indication is for the first transmission failure reason, the adjustment is increasing the backoff and the retransmission of the UL data is self-decodable; and the processor and the transceiver configured to retransmit the UL data to the base station using the adjusted backoff and determined retransmission scheme. ### Claim 2 (depends on 1) The WTRU of claim 1, wherein a total number of RBs in the first set is greater than a total number of RBs in the second set. ### Claim 3 (depends on 1) The WTRU of claim 1, wherein the first resource pool is for at least one of WTRU identity (ID) information and control information for the WTRU, and the second resource pool is for data information. ### Claim 4 (depends on 1) The WTRU of claim 1, wherein the subset of RBs in the first set are selected randomly. ### Claim 5 (depends on 1) The WTRU of claim 1, wherein the subset of RBs in the first set are selected using a random access procedure and a backoff procedure. ### Claim 6 (depends on 5) The WTRU of claim 5, wherein the random access procedure and the backoff procedure are based on one or more of a WTRU priority, a traffic type of UL data, and the received one or more GL transmission configurations. ### Claim at position 7 7-8. (canceled) ### Claim 9 (depends on 1) The WTRU of claim 1, wherein on a condition that the third indication is for the second transmission failure reason, the adjustment is decreasing the backoff and the retransmission of the UL data uses incremental redundancy (IR)/Chase combining (CC) hybrid automatic repeat request (HARQ) combining. ### Claim 10 (depends on 1) The WTRU of claim 1, wherein a time period between the reception of the GL transmission configuration and a transmission of the UL data is based on a backoff, and a time period between a transmission of the UL data and a retransmission of the UL data is based on a backoff. ### Claim 11 (depends on 1) The WTRU of claim 1, wherein adjusting the backoff includes adjusting a backoff impact factor. ### Claim 12 (depends on 1) The WTRU of claim 1, wherein the NAK is an RB based NAK. ### Claim 13 (depends on 1) The WTRU of claim 1, further comprising: the processor and the transceiver configured to transmit at least one of WTRU ID information for the WTRU and UL control information for the WTRU, via the selected subset of RBs in the first set, to a base station. ### Claim 14 (depends on 1) The WTRU of claim 1, wherein an RB group (RBG) includes one or more RBs. ### Claim 15 A method for use in a base station for grant-less (GL) uplink (UL) reception, the method comprising: transmitting one or more GL transmission configurations, including a first indication of a first set of resource blocks (RBs) for a first resource pool and a second indication of a second set of RBs for a second resource pool; determining whether UL data has been received successfully, via a subset of RBs within the second set, from a first WTRU; on a condition that the UL data has not been received successfully, determining, based on a first resource pool to second resource pool mapping, whether the first WTRU and at least a second WTRU have selected the subset of RBs of the second set; on a condition that the first WTRU and at least the second WTRU have selected the subset of RBs of the second set, transmitting to the WTRU a negative acknowledgement (NAK) with a third indication for a first transmission failure reason and receiving from the WTRU a UL self-decodable data retransmission, wherein the first transmission failure reason is due to UL collision; and on a condition that the first WTRU and at least the second WTRU have not selected the subset of RBs of the second set, transmitting to the WTRU a NAK with a third indication for a second transmission failure reason, wherein the second transmission failure reason is due to UL low Signal-to-Noise Ratio (SNR). ### Claim 16 (depends on 15) The method of claim 15, wherein a total number of RBs in the first set is greater than a total number of RBs in the second set. ### Claim 17 (depends on 15) The method of claim 15, wherein the first resource pool is for at least one of WTRU identity (ID) information and control information, and the second resource pool is for data information. ### Claim 18 (canceled) ### Claim 19 (depends on 15) The method of claim 15, further comprising: receiving, via a first subset of RBs in the first set and a second subset of RBs in the first set, UL control information. ### Claim 20 (depends on 15) The method of claim 15, further comprising: receiving, via a first subset of RBs in the first set, WTRU ID information for the first WTRU, and, via a second subset of RBs in the first set, WTRU ID information for the second WTRU. ### Claim 21 A method for use in a wireless transmit/receive unit (WTRU) for grant-less (GL) uplink (UL) transmissions, the method comprising: receiving one or more GL transmission configurations, including a first indication of a first set of resource blocks (RBs) for a first resource pool, and a second indication of a second set of RBs for a second resource pool; selecting a subset of RBs in the first set; determining a subset of RBs in the second set based on the selected subset of RBs in the first set; transmitting UL data, via the determined subset of RBs in the second set, to a base station; receiving a negative acknowledgement (NAK) with a third indication for at least one of a first transmission failure reason and a second transmission failure reason, wherein the first transmission failure reason is due to UL collision and the second transmission failure reason is due to UL low Signal-to-Noise Ratio (SNR); adjusting a backoff and determining a retransmission scheme based on the received third indication, wherein on a condition that the third indication is for the first transmission failure reason, the adjustment is increasing the backoff and the retransmission of the UL data is self-decodable; and retransmitting the UL data to the base station using the adjusted backoff and determined retransmission scheme. ### Claim 22 (depends on 21) The method of claim 21, wherein a total number of RBs in the first set is greater than a total number of RBs in the second set. ### Claim 23 (depends on 21) The method of claim 21, wherein the first resource pool is for at least one of WTRU identity (ID) information and control information for the WTRU, and the second resource pool is for data information.