# US 12,120,568 B2 · Method and apparatus for system information acquisition, beam failure recovery and cell reselection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,120,568 B2 - Document ID: US12120568B2 - Status: Granted - Kind: B2 - Application number: 18/528,089 - Filed: 2023-12-04 - Published: 2024-04-04 - Granted: 2024-10-15 - Earliest claimed: 2018-09-17 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Anil Agiwal; Soenghun Kim; Jaehyuk Jang - Web page: https://patentgrep.com/patent/US12120568B2 ## CPC - H04W 48/14: using user query {or user detection} - H04W 80/02: Data link layer protocols - H04B 7/0695: {using beam selection} - H04B 7/06964: {Re-selection of one or more beams after beam failure} - H04B 7/088: {using beam selection} - H04L 5/001: {the frequencies being arranged in component carriers} - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04L 5/0055: {Physical resource allocation for ACK/NACK (for physical mapping arrangements in ARQ protocols H04L1/1861)} - H04W 24/08: Testing, {supervising or monitoring} using real traffic - H04W 36/08: Reselecting an access point - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04W 76/11: Allocation or use of connection identifiers - H04W 76/27: Transitions between radio resource control [RRC] states - H04W 48/20: Selecting an access point - 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) - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract The disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. An apparatus, a method and a system for system information acquisition, beam failure recovery, and cell reselection in wireless communication system are provided. ## Claims ### Claim 1 A method performed by a terminal in a wireless communication system, the method comprising: detecting a beam failure for a special cell (SpCell); and in case that a physical random access channel (PRACH) occasion is not configured for an active uplink (UL) bandwidth part (BWP) of the SpCell, switching the active UL BWP to an initial UL BWP and an active downlink (DL) BWP to an initial DL BWP; and performing a random access procedure for a beam failure recovery of the SpCell based on a first beam failure recovery configuration of the initial UL BWP. ### Claim 2 (depends on 1) The method of claim 1, further comprising: in case that the PRACH occasion is configured for the active UL BWP, performing the random access procedure for the beam failure recovery of the SpCell based on a second beam failure recovery configuration of the active UL BWP. ### Claim 3 (depends on 1) The method of claim 1, further comprising: in case that the PRACH occasion is configured for the active UL BWP, applying at least one of power ramping step parameter, preamble received target power parameter, or preamble transmission maximum parameter of a second beam failure recovery configuration for the random access procedure; and in case that the PRACH occasion is not configured for the active UL BWP, applying at least one of power ramping step parameter, preamble received target power parameter, or preamble transmission maximum parameter of the first beam failure recovery configuration for the random access procedure. ### Claim 4 (depends on 1) The method of claim 1, wherein a beam failure recovery timer is started based on an initiation of the random access procedure. ### Claim 5 (depends on 1) The method of claim 1, wherein the first beam failure recovery configuration and a second beam failure recovery configuration are received by a radio resource control (RRC) signaling for the initial UL BWP and the active UL BWP, respectively. ### Claim 6 A method performed by a base station in a wireless communication system, the method comprising: transmitting, to a terminal, a radio resource control (RRC) signaling associated with a beam failure recovery; and in case that a physical random access channel (PRACH) occasion is not configured for an active uplink (UL) bandwidth part (BWP) of a special cell (SpCell), switching the active UL BWP to an initial UL BWP and an active downlink (DL) BWP to an initial DL BWP for the terminal which detected the beam failure recovery of the SpCell; and performing, with the terminal, a random access procedure for the beam failure recovery of the SpCell based on a first beam failure recovery configuration on the initial UL BWP. ### Claim 7 (depends on 6) The method of claim 6, further comprising: performing, with the terminal, the random access procedure for the beam failure recovery of the SpCell based on a second beam failure recovery configuration of the active UL BWP, in case that the PRACH occasion is configured for the active UL BWP. ### Claim 8 (depends on 6) The method of claim 6, wherein, in case that the PRACH occasion is configured for the active UL BWP, at least one of power ramping step parameter, preamble received target power parameter, or preamble transmission maximum parameter of a second beam failure recovery configuration is applied for the random access procedure, and wherein, in case that the PRACH occasion is not configured for the active UL BWP, at least one of power ramping step parameter, preamble received target power parameter, or preamble transmission maximum parameter of the first beam failure recovery configuration is applied for the random access procedure. ### Claim 9 (depends on 6) The method of claim 6, wherein a beam failure recovery timer is started based on an initiation of the random access procedure. ### Claim 10 (depends on 6) The method of claim 6, wherein the first beam failure recovery configuration and a second beam failure recovery configuration are transmitted by the RRC signaling for the initial UL BWP and the active UL BWP, respectively. ### Claim 11 A terminal in a wireless communication system, the terminal comprising: a transceiver configured to transmit and receive a signal; and a controller configured to: detect a beam failure for a special cell (SpCell), and in case that a physical random access channel (PRACH) occasion is not configured for an active uplink (UL) bandwidth part (BWP) of the SpCell, switch the active UL BWP to an initial UL BWP and an active downlink (DL) BWP to an initial DL BWP, and perform a random access procedure for a beam failure recovery of the SpCell based on a first beam failure recovery configuration of the initial UL BWP. ### Claim 12 (depends on 11) The terminal of claim 11, wherein the controller is further configured to: in case that the PRACH occasion is configured for the active UL BWP, perform the random access procedure for the beam failure recovery of the SpCell based on a second beam failure recovery configuration of the active UL BWP. ### Claim 13 (depends on 11) The terminal of claim 11, wherein the controller is further configured to: in case that the PRACH occasion is configured for the active UL BWP, apply at least one of power ramping step parameter, preamble received target power parameter, or preamble transmission maximum parameter of a second beam failure recovery configuration for the random access procedure, and in case that the PRACH occasion is not configured for the active UL BWP, apply at least one of power ramping step parameter, preamble received target power parameter, or preamble transmission maximum parameter of the first beam failure recovery configuration for the random access procedure. ### Claim 14 (depends on 11) The terminal of claim 11, wherein a beam failure recovery timer is started based on an initiation of the random access procedure. ### Claim 15 (depends on 11) The terminal of claim 11, wherein the first beam failure recovery configuration and a second beam failure recovery configuration are received by a radio resource control (RRC) signaling for the initial UL BWP and the active UL BWP, respectively. ### Claim 16 A base station in a wireless communication system, the base station comprising: a transceiver configured to transmit and receive a signal; and a controller configured to: transmit, to a terminal, a radio resource control (RRC) signaling associated with a beam failure recovery, and in case that a physical random access channel (PRACH) occasion is not configured for an active uplink (UL) bandwidth part (BWP) of a special cell (SpCell), switch the active UL BWP to an initial UL BWP and an active downlink (DL) BWP to an initial DL BWP for the terminal which detected the beam failure recovery of the SpCell, and perform, with the terminal, a random access procedure for the beam failure recovery of the SpCell based on a first beam failure recovery configuration on the initial UL BWP. ### Claim 17 (depends on 16) The base station of claim 16, wherein the controller is further configured to: perform, with the terminal, the random access procedure for the beam failure recovery of the SpCell based on a second beam failure recovery configuration of the active UL BWP, in case that the PRACH occasion is configured for the active UL BWP. ### Claim 18 (depends on 16) The base station of claim 16, wherein, in case that the PRACH occasion is configured for the active UL BWP, at least one of power ramping step parameter, preamble received target power parameter, or preamble transmission maximum parameter of a second beam failure recovery configuration is applied for the random access procedure, and wherein, in case that the PRACH occasion is not configured for the active UL BWP, at least one of power ramping step parameter, preamble received target power parameter, or preamble transmission maximum parameter of the first beam failure recovery configuration is applied for the random access procedure. ### Claim 19 (depends on 16) The base station of claim 16, wherein a beam failure recovery timer is started based on an initiation of the random access procedure. ### Claim 20 (depends on 16) The base station of claim 16, wherein the first beam failure recovery configuration and a second beam failure recovery configuration are transmitted by the RRC signaling for the initial UL BWP and the active UL BWP, respectively.