# US 12,225,595 B2 · Channel access method for performing transmission in unlicensed band, and device using same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,225,595 B2 - Document ID: US12225595B2 - Status: Granted - Kind: B2 - Application number: 18/381,966 - Filed: 2023-10-19 - Published: 2024-02-08 - Granted: 2025-02-11 - Earliest claimed: 2019-08-06 - Assignees: Wilus Institute of Standards and Technology Inc. - Applicants: Wilus Institute of Standards and Technology Inc. - Inventors: Minseok Noh; Kyungjun Choi; Jinsam Kwak - Web page: https://patentgrep.com/patent/US12225595B2 ## CPC - H04L 5/001: {the frequencies being arranged in component carriers} - H04W 74/085: {collision avoidance} - H04W 16/14: Spectrum sharing arrangements {between different networks} - H04W 72/1263: Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04W 74/0816: with collision avoidance - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04W 74/0866: {using a dedicated channel for access} - H04L 5/0098: {Signalling of the activation or deactivation of component carriers, subcarriers or frequency bands} - H04W 74/0808: using carrier sensing, e.g. carrier sense multiple access [CSMA] - 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 A base station of a wireless communication system is disclosed. The base station of wireless communication includes a communication module and a processor. The processor is configured to receive a grant for scheduling a plurality of uplink transmissions from the base station, and when the UE attempts to a first fixed duration-based channel access for a first transmission which is one of the plurality of uplink transmission and fails in the first fixed duration-based channel access, attempt to a second fixed duration-based channel access for a second transmission which is a transmission following the first transmission. ## Claims ### Claim 1 A user equipment (UE) for use in a wireless communication system, the UE comprising: a communication module; and a processor controlling the communication module, wherein the processor is configured to: attempt to transmit a transmission using a first channel access procedure, the first channel access procedure including a channel sensing for a time interval of 16 μs before the transmission; and if the first channel access procedure for the transmission is failed, and the transmission is in a set of contiguous transmissions prior to a last transmission of the set, attempt to transmit a next transmission in the set using a second channel access procedure, the second channel access procedure including a channel sensing for a time interval of 25 μs before the next transmission. ### Claim 2 (depends on 1) The UE of claim 1, wherein the transmission includes a physical shared channel transmission. ### Claim 3 (depends on 1) The UE of claim 1, wherein the set of contiguous transmissions is within a channel occupancy time (COT). ### Claim 4 (depends on 1) The UE of claim 1, wherein the UE attempts to transmit the set of contiguous transmissions in association with one or more grants. ### Claim 5 (depends on 1) The UE of claim 1, wherein, if the first channel access procedure is succeeded, the transmission is transmitted immediately after the time interval of 16 μs. ### Claim 6 (depends on 1) The UE of claim 1, wherein, if the second channel access procedure is succeeded, the next transmission is transmitted immediately after the time interval of 25 μs. ### Claim 7 (depends on 1) The UE of claim 1, wherein the first and second channel access procedures do not include a random-backoff operation. ### Claim 8 (depends on 1) The UE of claim 1, wherein the wireless communication system includes a 3rd generation partnership project new radio (3GPP NR)-based wireless communication system supporting unlicensed band operations. ### Claim 9 A method for use by a user equipment (UE) in a wireless communication system, the method comprising: attempting to transmit a transmission using a first channel access procedure, the first channel access procedure including a channel sensing for a time interval of 16 μs before the transmission; and if the first channel access procedure for the transmission is failed, and the transmission is in a set of contiguous transmissions prior to a last transmission of the set, attempting to transmit a next transmission in the set using a second channel access procedure, the second channel access procedure including a channel sensing for a time interval of 25 μs before the next transmission. ### Claim 10 (depends on 9) The method of claim 9, wherein the transmission includes a physical shared channel transmission. ### Claim 11 (depends on 9) The method of claim 9, wherein the set of contiguous transmissions is within a channel occupancy time (COT). ### Claim 12 (depends on 9) The method of claim 9, wherein the UE attempts to transmit the set of contiguous transmissions in association with one or more grants. ### Claim 13 (depends on 9) The method of claim 9, wherein, if the first channel access procedure is succeeded, the transmission is transmitted immediately after the time interval of 16 μs. ### Claim 14 (depends on 9) The method of claim 9, wherein, if the second channel access procedure is succeeded, the next transmission is transmitted immediately after the time interval of 25 μs. ### Claim 15 (depends on 9) The method of claim 9, wherein the first and second channel access procedures do not include a random-backoff operation. ### Claim 16 (depends on 9) The method of claim 9, wherein the wireless communication system includes a 3rd generation partnership project new radio (3GPP NR)-based wireless communication system supporting unlicensed band operations.