# US 11,445,567 B2 · Method and apparatus for RRC state transition > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,445,567 B2 - Document ID: US11445567B2 - Status: Granted - Kind: B2 - Application number: 16/537,414 - Filed: 2019-08-09 - Published: 2020-02-13 - Granted: 2022-09-13 - Earliest claimed: 2018-08-10 - Assignees: FG Innovation Company Limited - Applicants: FG Innovation Company Limited - Inventors: Mei-Ju Shih; Yung-Lan Tseng; Hung-Chen Chen; Chie-Ming Chou - Web page: https://patentgrep.com/patent/US11445567B2 ## CPC - H04W 76/27: Transitions between radio resource control [RRC] states - H04W 48/20: Selecting an access point - Y02D 30/70: in wireless communication networks - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract A user equipment (UE) includes one or more non-transitory computer-readable media having computer-executable instructions embodied thereon and at least one processor coupled to the one or more non-transitory computer-readable media. The at least one processor is configured to execute the computer-executable instructions to: receive, from a cell, a radio access network (RAN) notification area (RNA) configuration, when the UE is in an RRC_INACTIVE state; and discard the RNA configuration and transitioning to an RRC_IDLE state when the UE finds and camps on an acceptable cell. ## Claims ### Claim 1 A user equipment (UE), comprising: one or more non-transitory computer-readable media having computer-executable instructions embodied thereon; and at least one processor coupled to the one or more non-transitory computer-readable media, the at least one processor being configured to execute the computer-executable instructions to cause the UE to: receive, from a serving cell, a radio access network (RAN) notification area (RNA) configuration when the UE is in a radio resource control (RRC) inactive (RRC_INACTIVE) state; transition from the RRC_INACTIVE state to an RRC idle (RRC_IDLE) state when the UE finds and camps on an acceptable cell that fulfills a minimum set of requirements to initiate an emergency call and to receive Earthquake & Tsunami Warning System (ETWS) and Commercial Mobile Alert System (CMAS) notifications, wherein the UE obtains limited service within a coverage area of the acceptable cell, and the serving cell and the acceptable cell are associated with a same core network; and discard the RNA configuration that comprises at least one of a list of tracking area identities (IDs) and a list of RAN area IDs in response to the transitioning from the RRC_INACTIVE state to the RRC_IDLE state. ### Claim 2 (depends on 1) The UE of claim 1, wherein the at least one processor is further configured to execute the computer-executable instructions to cause the UE to: transition to a first sub-state of the RRC_INACTIVE state when the UE does not find any suitable cell during a cell reselection evaluation process; and attempt to find a suitable cell that is configured in the RNA configuration when the UE is in the first sub-state of the RRC_INACTIVE state. ### Claim 3 (depends on 2) The UE of claim 2, wherein the at least one processor is further configured to execute the computer-executable instructions to cause the UE to: receive, via one of system information from a camped cell and dedicated signaling of the serving cell, a priority order used in the cell reselection evaluation process. ### Claim 4 (depends on 3) The UE of claim 3, wherein the at least one processor is further configured to execute the computer-executable instructions to cause the UE to: ignore the priority order when a timer expires. ### Claim 5 (depends on 2) The UE of claim 2, wherein the at least one processor is further configured to execute the computer-executable instructions to cause the UE to: transition to a second sub-state of the RRC_INACTIVE state when the UE finds a suitable cell that is configured in the RNA configuration; and trigger an RNA update procedure. ### Claim 6 (depends on 2) The UE of claim 2, wherein the at least one processor is further configured to execute the computer-executable instructions to cause the UE to: receive, from the serving cell, a periodic RNA update timer; and stay in the first sub-state of the RRC_INACTIVE state when the UE is in the first sub-state of the RRC_INACTIVE state and the periodic RNA update timer expires. ### Claim 7 (depends on 2) The UE of claim 2, wherein the at least one processor is further configured to execute the computer-executable instructions to cause the UE to: receive, from the serving cell, a periodic RNA update timer; and restart the periodic RNA update timer when the UE is in the first sub-state of the RRC_INACTIVE state and the periodic RNA update timer expires. ### Claim 8 (depends on 2) The UE of claim 2, wherein the at least one processor is further configured to execute the computer-executable instructions to cause the UE to: receive, from the serving cell, a periodic RNA update timer; pause the periodic RNA update timer when the UE transitions to the first sub-state of the RRC_INACTIVE state; and resume the periodic RNA update timer when the UE leaves the first sub-state of the RRC_INACTIVE state. ### Claim 9 (depends on 1) The UE of claim 1, wherein the at least one processor is further configured to execute the computer-executable instructions to cause the UE to: receive a paging message from a suitable cell, wherein the paging message comprises a paging record, and the paging record comprises a UE identity; and initiate an RRC connection resumption procedure when the UE identity in the paging record matches an inactive radio network temporary identifier (I-RNTI) stored in the UE. ### Claim 10 (depends on 1) The UE of claim 1, wherein the at least one processor is further configured to execute the computer-executable instructions to cause the UE to: receive public land mobile network (PLMN) information from a camped cell, wherein the PLMN information comprises a PLMN identity that is configured in the RNA configuration; report, by an access stratum (AS) layer of the UE, the PLMN identity to a non-access stratum (NAS) layer of the UE; and perform a PLMN selection procedure. ### Claim 11 A method performed by a user equipment (UE), the method comprising: receiving, from a serving cell, a radio access network (RAN) notification area (RNA) configuration when the UE is in a radio resource control (RRC) inactive (RRC_INACTIVE) state; transitioning from the RRC_INACTIVE state to an RRC idle (RRC_IDLE) state when the UE finds and camps on an acceptable cell that fulfills a minimum set of requirements to initiate an emergency call and to receive Earthquake & Tsunami Warning System (ETWS) and Commercial Mobile Alert System (CMAS) notifications, wherein the UE obtains limited service within a coverage area of the acceptable cell, and the serving cell and the acceptable cell are associated with a same core network; and discarding the RNA configuration that comprises at least one of a list of tracking area identities (IDs) and a list of RAN area IDs in response to the transitioning from the RRC_INACTIVE state to the RRC_IDLE state. ### Claim 12 (depends on 11) The method of claim 11, further comprising: transitioning to a first sub-state of the RRC_INACTIVE state when the UE does not find any suitable cell during a cell reselection evaluation process; and attempting to find a suitable cell that is configured in the RNA configuration when the UE is in the first sub-state of the RRC_INACTIVE state. ### Claim 13 (depends on 12) The method of claim 12, further comprising: receiving, via one of system information from a camped cell and dedicated signaling of the serving cell, a priority order used in the cell reselection evaluation process. ### Claim 14 (depends on 13) The method of claim 13, further comprising: ignoring the priority order when a timer expires. ### Claim 15 (depends on 12) The method of claim 12, further comprising: transitioning to a second sub-state of the RRC_INACTIVE state when the UE finds a suitable cell that is configured in the RNA configuration; and triggering an RNA update procedure. ### Claim 16 (depends on 12) The method of claim 12, further comprising: receiving, from the serving cell, a periodic RNA update timer; and staying in the first sub-state of the RRC_INACTIVE state when the UE is in the first sub-state of the RRC_INACTIVE state and the periodic RNA update timer expires. ### Claim 17 (depends on 12) The method of claim 12, further comprising: receiving, from the serving cell, a periodic RNA update timer; and restarting the periodic RNA update timer when the UE is in the first sub-state of the RRC_INACTIVE state and the periodic RNA update timer expires. ### Claim 18 (depends on 12) The method of claim 12, further comprising: receiving, from the serving cell, a periodic RNA update timer; pausing the periodic RNA update timer when the UE transitions to the first sub-state of the RRC_INACTIVE state; and resuming the periodic RNA update timer when the UE leaves the first sub-state of the RRC_INACTIVE state. ### Claim 19 (depends on 11) The method of claim 11, further comprising: receiving a paging message from a suitable cell, wherein the paging message comprises a paging record, and the paging record comprises a UE identity; and initiating an RRC connection resumption procedure when the UE identity in the paging record matches an inactive radio network temporary identifier (I-RNTI) stored in the UE. ### Claim 20 (depends on 11) The method of claim 11, further comprising: receiving public land mobile network (PLMN) information from a camped cell, wherein the PLMN information comprises a PLMN identity that is configured in the RNA configuration; reporting, by an access stratum (AS) layer of the UE, the PLMN identity to a non-access stratum (NAS) layer of the UE; and performing a PLMN selection procedure.