# US 12,120,736 B2 · Device and method for channel access in wireless communication system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,120,736 B2 - Document ID: US12120736B2 - Status: Granted - Kind: B2 - Application number: 17/309,884 - Filed: 2019-12-27 - Published: 2022-03-24 - Granted: 2024-10-15 - Earliest claimed: 2018-12-27 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Jinyoung Oh; Jeongho Yeo; Hyunseok Ryu; Sungjin Park; Jonghyun Bang; Cheolkyu Shin - Web page: https://patentgrep.com/patent/US12120736B2 ## CPC - H04W 74/002: {Transmission of channel access control information} - H04W 74/0816: with collision avoidance - H04L 1/1812: Hybrid protocols; Hybrid automatic repeat request [HARQ] - H04L 1/201: {Frame classification, e.g. bad, good or erased (frame indication per se H04L1/0082)} - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04W 72/0446: Resources in time domain, e.g. slots or frames - H04W 74/006: {in the downlink, i.e. towards the terminal} - H04W 74/0866: {using a dedicated channel for access} - H04L 1/1854: {Scheduling and prioritising arrangements} - H04L 1/1887: {Scheduling and prioritising arrangements} - H04W 74/0808: using carrier sensing, e.g. carrier sense multiple access [CSMA] - H04W 74/0833: Random access procedures, e.g. with 4-step access - 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 The present disclosure relates to a communication method and its system for converging a 5th-Generation (5G) communication system for supporting a higher data rate than a 4th-Generation (4G) system with an Internet of things (IoT) technology. The present disclosure may be applied to intelligent services based on the 5G communication technology and an IoT-related technology (e.g., a smart home, a smart building, a smart city, a smart car or a connected car, health care, digital education, retail, security and safety services). According to various embodiments of the present disclosure, an operating method of a base station, in a wireless communication system, may include performing a channel access procedure in an unlicensed band, obtaining a transmission result of a downlink signal for a reference slot based on the channel access procedure, and determining a size of a contention section for a next channel access procedure, based on the transmission result, and the reference slot may be a starting slot in downlink transmission by the base station. ## Claims ### Claim 1 A method performed by a base station, in a wireless communication system, comprising: performing a channel access procedure for a channel occupancy time (COT) in an unlicensed band; obtaining a hybrid automatic repeat request-acknowledge (HARQ-ACK) feedback for a reference duration based on the channel access procedure, wherein the HARQ-ACK feedback comprises a transmission result for at least one code block group (CBG) transmitted on a physical downlink shared channel (PDSCH) or at least one transmission result for at least one transport block (TB) transmitted on at least one PDSCH; in case that a ratio of ACKs for the at least one CBG is greater than a threshold based on the HARQ-ACK feedback, identifying a size of a contention window for a next channel access procedure as a minimum size; and in case that the at least one transmission result for the TB in the reference duration corresponds to at least one ACK, identifying the size of the contention window as the minimum size, wherein the reference duration comprises a first slot where the at least one PDSCH is transmitted after the COT is started, the COT being initiated by the base station. ### Claim 2 (depends on 1) The method of claim 1, wherein a value of the threshold is predefined, and wherein the size of the contention window is determined as the minimum size according to a channel access priority. ### Claim 3 (depends on 1) The method of claim 1, further comprising: transmitting, to a user equipment (UE), downlink control information including a code block group transmission indication (CBGTI) field, and wherein the CBGTI field indicates the at least one CBG for the HARQ-ACK feedback. ### Claim 4 (depends on 1) The method of claim 1, wherein the reference duration includes at least one symbol of a slot, and wherein at least one remaining symbol of the slot is not in the COT. ### Claim 5 A method performed by a user equipment (UE), in a wireless communication system, comprising: performing a channel access procedure for a channel occupancy time (COT) in an unlicensed band; obtaining a hybrid automatic repeat request-acknowledge (HARQ-ACK) feedback for a reference duration based on the channel access procedure, wherein the HARQ-ACK feedback comprises a transmission result for at least one code block group (CBG) transmitted on a physical uplink shared channel (PUSCH) or at least one transmission result for at least one transport block (TB) transmitted on at least one PUSCH; in case that a ratio of ACKs for the at least one CBG is greater than a threshold based on the HARQ-ACK feedback, identifying a size of a contention window for a next channel access procedure as a minimum size; and in case that the at least one transmission result for the TB in the reference duration corresponds to at least one ACK, identifying the size of the contention window as the minimum size, wherein the reference duration comprises a first slot where the at least one PUSCH is transmitted after the COT is started, the COT being initiated by a base station. ### Claim 6 (depends on 5) The method of claim 5, wherein a value of the threshold is predefined, and wherein the size of the contention window is determined as the minimum size according to a channel access priority. ### Claim 7 (depends on 5) The method of claim 5, further comprising: receiving, from a base station, downlink control information including a code block group transmission indication (CBGTI) field, and wherein the CBGTI field is associated with the HARQ-ACK feedback. ### Claim 8 (depends on 5) The method of claim 5, wherein the reference duration includes at least one symbol of a slot, and wherein at least one remaining symbol of the slot is not in the COT. ### Claim 9 A base station, in a wireless communication system, comprising: at least one transceiver; and at least one processor, wherein the at least one processor is configured to: perform a channel access procedure for a channel occupancy time (COT) in an unlicensed band; obtain a hybrid automatic repeat request-acknowledge (HARQ-ACK) feedback for a reference duration based on the channel access procedure, wherein the HARQ-ACK feedback comprises a transmission result for at least one code block group (CBG) transmitted on a physical downlink shared channel (PDSCH) or at least one transmission result for at least one transport block (TB) transmitted on at least one PDSCH; in case that a ratio of ACKs for the at least one CBG is greater than a threshold based on the HARQ-ACK feedback, identify a size of a contention window for a next channel access procedure as a minimum size; and in case that the at least one transmission result for the TB in the reference duration corresponds to at least one ACK, identify the size of the contention window as the minimum size, wherein the reference duration comprises a first slot where the at least one PDSCH is transmitted after the COT is started, the COT being initiated by the base station. ### Claim 10 (depends on 9) The base station of claim 9, wherein a value of the threshold is predefined, and wherein the size of the contention window is determined as the minimum size according to a channel access priority. ### Claim 11 (depends on 9) The base station of claim 9, wherein the at least one processor is further configured to: transmit, to a user equipment (UE), downlink control information including a code block group transmission indication (CBGTI) field, and wherein the CBGTI field indicates the at least one CBG for the HARQ-ACK feedback. ### Claim 12 (depends on 9) The base station of claim 9, wherein the reference duration includes at least one symbol of a slot, and wherein at least one remaining symbol of the slot is not in the COT. ### Claim 13 A user equipment (UE), in a wireless communication system, comprising: at least one transceiver; and at least one processor, wherein the at least one processor is configured to: perform a channel access procedure for a channel occupancy time (COT) in an unlicensed band; obtain a hybrid automatic repeat request-acknowledge (HARQ-ACK) feedback for a reference duration based on the channel access procedure, wherein the HARQ-ACK feedback comprises a transmission result for at least one code block group (CBG) transmitted on a physical uplink shared channel (PUSCH) or at least one transmission result for at least one transport block (TB) transmitted on at least one PUSCH; in case that a ratio of ACKs for the at least one CBG is greater than a threshold based on the HARQ-ACK feedback, identify a size of a contention window for a next channel access procedure as a minimum size; and in case that the at least one transmission result for the TB in the reference duration corresponds to at least one ACK, identify the size of the contention window as the minimum size, wherein the reference duration comprises a first slot where at least one PUSCH is transmitted after the COT is started, the COT being initiated by a base station. ### Claim 14 (depends on 13) The UE of claim 13, wherein a value of the threshold is predefined, and wherein the size of the contention window is determined as the minimum size according to a channel access priority. ### Claim 15 (depends on 13) The UE of claim 13, wherein the at least one processor is further configured to: receive, from a base station, downlink control information including a code block group transmission indication (CBGTI) field, and wherein the CBGTI field is associated with the HARQ-ACK feedback. ### Claim 16 (depends on 13) The UE of claim 13, wherein the reference duration includes at least one symbol of a slot, and wherein at least one remaining symbol of the slot is not in the COT. ### Claim 17 (depends on 13) The UE of claim 13, wherein the at least one processor is further configured to: in case that at least one HARQ-ACK feedback for at least PUSCH in the reference duration corresponds to an ACK, identify the size of the contention window as the minimum size.