Abstract: A method and apparatus for resuming only signaling radio bearers (SRBs) in a wireless communication system is provided. A wireless device triggers a signaling while the wireless device is in a radio resource control (RRC) inactive state, and resumes only SRB and transmits a message 3 (MSG3) of a random access procedure to a network when an early data transmission (EDT) triggering condition for transmission via the MSG3 is fulfilled. The MSG3 includes the signaling.

Abstract: Disclosed are a method for requesting an RRC connection and an apparatus supporting same. The method comprises the steps of: generating a message for an RRC connection request; generating a header including an indicator indicating a use relating to the RRC connection request of the generated message, and generating a medium access control protocol data unit (MAC PDU) including the generated message; and transmitting the generated MCA PDU to a base station.

Abstract: Provided is a method for changing, by a user equipment (UE), packet data convergence protocol (PDCP) version. The method may include: receiving a security mode command message, which includes a first security algorithm configuration for a PDCP of a first system and a second security algorithm configuration for a PDCP of a second system, from a base station (BS); deriving a first security key for the PDCP of the first system, based on the first security algorithm configuration; when the security mode command message passes an integrity protection check based on the first security key, changing the PDCP version from the PDCP of the first system to the PDCP of the second system; deriving a second security key for the PDCP of the second system, based on the second security algorithm configuration; and transmitting a security mode complete message, based on the second security key, to the BS.

Abstract: A method and apparatus for supporting security in a radio resource control (RRC) inactive state in a wireless communication system is provided. A user equipment (UE) receives information on multiple security variables, of which each variable is mapped to each of multiple counter values, respectively. The UE calculates a security parameter and/or updating a UE identifier (ID) based on a security variable among the security variables which is mapped to a corresponding counter value among the multiple counter values, and transmits a radio resource control (RRC) resume request message including the calculated security parameter and/or the updated UE ID. The counter value may be increase whenever a timer expires or an RRC reject message is received as a response to the RRC resume request message.

Abstract: Provided are a method of managing UE context and a device supporting the method. According to one embodiment of the present invention, a method for managing UE context in a wireless communication system includes: receiving a UE context request message including a radio resource control (RRC) establishment cause from a second BS, wherein the first BS and the second BS are located in a same radio access network (RAN)-based notification area (RNA); and when the RRC establishment cause is related to RNA update, transmitting a UE context response message to the second BS, wherein the UE context response message piggybacks a RRC message requesting a UE to move to a RRC inactive state.

Abstract: A method and apparatus for performing a conditional cell change in a wireless communication system is provided. A wireless device receives a conditional mobility configuration associated with multiple target cells from a serving node. The conditional mobility configuration includes mobility commands for each of the multiple target cells. The wireless device receives information on one target cell among the multiple target cells from the serving node, and performs a mobility towards the one target cell based on a mobility command for the one target cell.

Abstract: Provided are a method for performing, by a user equipment (UE), transmission via only a primary path in a wireless communication system, and an apparatus supporting the same. The method may include: configuring a split bearer, which has multiple L2 entities for both a master cell group (MCG) and a secondary cell group (SCG); when the UE transits from a first state to a second state, reconfiguring the primary path of the split bearer autonomously; and performing the transmission via only the primary path of the split bearer, wherein the primary path is related to an L2 entity for the MCG.

Abstract: A method and apparatus for controlling radio resource of a redundant route for a dual-connecting Integrated Access and Backhaul (IAB) node in a wireless communication system will be provided. The CU of the IAB-donor is connected with a dual-connecting IAB-node via a master cell group (MCG) IAB-node. The CU of the IAB-donor initiates an establishment of a connection with the dual-connecting IAB-node via a secondary cell group (SCG) IAB-node. The CU of the IAB-donor transmits, to the SCG IAB-node, a first information which informs not allocating radio resource for a bearer. The CU of the IAB-donor determines to use the connection with the dual-connecting IAB-node via the SCG IAB-node. The CU of the IAB-donor transmits, to the SCG IAB-node, a second information to request allocating the radio resource for the bearer.

Abstract: A first network device receives a request associated with data notification for a user equipment (UE). When the UE is in a mode in which communication of mobile terminated data is restricted and the first network device detects that the UE is in a non-allowed area, the first network device rejects the request unless the data notification is for a regulatory prioritized service.

Abstract: A method and apparatus for resuming only signaling radio bearers (SRBs) in a wireless communication system is provided. A wireless device triggers a signaling while the wireless device is in a radio resource control (RRC) inactive state, and resumes only SRB and transmits a message 3 (MSG3) of a random access procedure to a network when an early data transmission (EDT) triggering condition for transmission via the MSG3 is fulfilled. The MSG3 includes the signaling.

Abstract: Provided are a method of performing RRC establishment procedure a device supporting the method. According to one embodiment of the present invention, the method includes: configuring a master cell group (MCG) cell and a secondary cell group (SCG) cell; receiving configuration related to MCG failure; detecting the MCG failure on the MCG cell; suspending MCG bearer and MCG transmission of split bearer; and transmitting a message to the SCG cell based on the configuration.

Abstract: A method and apparatus for transmitting data in a wireless communication system is provided. A user equipment (UE) transmits the data in a first cell during a first random access procedure, i.e. early data transmission. The UE detects that transmission of the data in the first cell during the first random access procedure has failed, and prioritizes a second cell based on candidate cell information. After selecting the second cell, the UE transmits a failed part of the data in the second cell during a second random access procedure.

Abstract: Provided are a method by which an access stratum (AS) layer of a terminal determines a radio resource control (RRC) state in a wireless communication system, and a device for supporting the same. The method can comprise the steps of: entering an RRC_INACTIVE state; receiving, from a core network (CN), CN paging in the RRC_INACTIVE state; forwarding a UE ID of the terminal and a CN domain to a non-access stratum (NAS) layer of the terminal; receiving an RRC connection release request from the NAS layer of the terminal; and entering an RRC_IDLE state on the basis of the received RRC connection release request.

Abstract: Provided are a method of reporting mobility history of an UE and a device supporting the method. According to one embodiment of the present invention, the method includes: leaving radio resource control (RRC) connected state; logging altitude information of the aerial UE when a specific condition is satisfied; and transmitting the altitude information when the aerial UE enters RRC connected state.

Abstract: A method for transmitting a packet by a Packet Data Convergence Protocol (PDCP) entity of a user equipment in a wireless communication system is disclosed. The method comprises delivering a packet to a first Radio Link Control (RLC) entity; and when a radio link failure (RLF) related to the first RLC entity is detected, retransmitting the packet through a second RLC entity if acknowledgement information of the packet is not received from the first RLC entity.

Abstract: Disclosed are a method for requesting an RRC connection and an apparatus supporting same. The method comprises the steps of: generating a message for an RRC connection request; generating a header including an indicator indicating a use relating to the RRC connection request of the generated message, and generating a medium access control protocol data unit (MAC PDU) including the generated message; and transmitting the generated MCA PDU to a base station.

Abstract: Provided is a method for changing, by a user equipment (UE), packet data convergence protocol (PDCP) version. The method may include: receiving a security mode command message, which includes a first security algorithm configuration for a PDCP of a first system and a second security algorithm configuration for a PDCP of a second system, from a base station (BS); deriving a first security key for the PDCP of the first system, based on the first security algorithm configuration; when the security mode command message passes an integrity protection check based on the first security key, changing the PDCP version from the PDCP of the first system to the PDCP of the second system; deriving a second security key for the PDCP of the second system, based on the second security algorithm configuration; and transmitting a security mode complete message, based on the second security key, to the BS.

Abstract: Provided are a method for keeping, by a user equipment (UE), a first dual connectivity (DC) configuration in a wireless communication system. The method may include: receiving information for validation of a DC configuration, from a network, wherein the DC configuration includes the first DC configuration and a second DC configuration; determining whether or not the first DC configuration is valid in a radio resource control (RRC) resume procedure, based on the information for validation of DC configuration; if the first DC configuration is valid, keeping the first DC configuration in an RRC resume procedure; and releasing the second DC configuration before initiating the RRC resume procedure.

Abstract: Provided is a method for a terminal performing an RRC connection reestablishment process in a wireless communication system. The method comprises the steps of: the terminal moving from a first base station to a second base station; transmitting, to the second base station, an RRC connection reestablishment request message; receiving, from the second base station, an RRC connection reestablishment message, wherein the RRC connection reestablishment message includes a state conversion indicator indicating an RRC state into which the terminal should enter; and entering the RRC state corresponding to the state conversion indicator.

Abstract: A method and apparatus for supporting a fast link recovery and link status reporting in a wireless communication system is provided. When a node detects a radio link problem on a wireless backhaul link between integrated access and backhaul (IAB) nodes from the node to a donor node of an TAB network, the node reselects a cell operated by a gNB which is directly connected to the donor node, and performs a random access procedure towards the cell operated by the gNB to report information on the radio link problem to the cell. The donor node may establish a new path for the node.