A UE (100) receives a handover command from a source cell to perform a handover to a target cell in response to the handover command. The handover command includes a notification indicating omitting a random access procedure during the handover. The UE (100) omits, in response to the notification, the random access procedure during the handover.

A communication device for handling a pre-allocated uplink (UL) grant comprises a storage device and a processing circuit, coupled to the storage device. The storage device stores, and the processing circuit is configured to execute instructions of: using a first temporary identity to perform a data communication with a first base station (BS) via a first cell; receiving a handover command from the first BS, wherein the handover command configures the pre-allocated UL grant and configures the communication device to perform a handover to a second cell; and releasing the pre-allocated UL grant in response to a failure, when detecting the failure before completing the handover to the second cell.

A communication apparatus includes an acquisition unit to acquire, from a base station apparatus being connected, switching information including information used for wireless communication with a movably configured base station apparatus to be a switching destination candidate, a determination unit configured to determine whether or not to switch a base station apparatus to be a connection destination, and a connection unit configured to, upon determining by the determination unit to switch the base station apparatus to be the connection destination, execute connection to the base station apparatus to be the switching destination candidate on a basis of the switching information.

A base station may communicate with a wireless device. A control message may direct the wireless device to switch from one link to another link and maintain the same cell identifier. The control message may specify whether the wireless device should perform or skip a random access channel procedure.

Methods and apparatuses for a RACH-less handover for a mobility operation in a wireless communication system. A method of a UE comprises: receiving a first message including configuration information for a RACH-less HO; determining whether the configuration information includes the CG configuration or the beam indication; identifying: a CG PUSCH occasion based on a determination that the configuration information includes the CG configuration, or a TCI state ID or a SSB index based on a determination that the configuration information includes the beam indication; and transmitting, to the target cell: an uplink signal including a second message in response to the first message at the identified CG PUSCH occasion when the configuration information includes the CG configuration, or the uplink signal based on an uplink grant received in a PDCCH, the PDCCH being monitored based on the beam indication when the configuration information includes the beam indication.

A user equipment apparatus (UE) includes processor(s) and memory storing instructions. The instructions, when executed by the processor(s), cause the UE at least to, establish a connection with a control network node via a serving cell, where the serving cell is supported by a source network node; receive, from the control network node and/or the source network node, timing advance (TA) cell configurations for a set of timing advance (TA) cells, where the TA cell configurations include a TA-associated random access (RA) configuration, where the set of TA cells includes first TA cells that include candidate target cells with which the UE may connect and/or other TA cells which are requested by at candidate target cells and which the UE may connect with in case the UE connects with the one of the candidate target cells; and acquire TA for the TA cell based on the TA-associated RA configuration.

Methods and apparatuses for uplink transmissions and receptions for random access channel (RACH)-less handover. A method includes receiving information for a first configuration for RACH-less handover procedure in a system information block (SIB) from a source cell, a first set of synchronization signal (SS) and physical broadcast channel (PBCH) (SS/PBCH) block indexes, a physical uplink shared channel (PUSCH) for a transmission of the PUSCH on a target cell, and a number of repetitions of the transmission of the PUSCH on the target cell. The method further includes determining a spatial setting for the transmission of the PUSCH and transmitting the PUSCH with the number of repetitions using the spatial setting on the target cell.

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. There is disclosed a method, for a second base station in a network comprising a User Equipment (UE), a first base station, and the second base station. The method is for performing Random Access Channel (RACH)-less handover of the UE from the first base station to the second base station. The method comprises: obtaining a Conditional Handover (CHO) configuration (e.g., execution condition); determining a RACH-less Uplink (UL) grant configuration; transmitting, to the first base station, the RACH-less UL grant (e.g., in a HANDOVER REQUEST ACK message); and monitoring for UL RACH-less transmissions from the UE (e.g., a RRCConnectionReconfigurationComplete message) or scheduling Physical Downlink Control Channel (PDCCH) assignments to the UE, based on the CHO configuration.

A method for receiving a radio resource control (RRC) message by a user equipment (UE) is described. The method includes receiving, from a base station, a radio resource control (RRC) connection reconfiguration message including data radio bearer (DRB) configuration parameters for remapping a DRB that is established on a master cell group (MCG), to a split DRB; and coupling a packet data convergence protocol (PDCP) that is established on the MCG to a radio link control (RLC) of the MCG and a RLC of a secondary cell group (SCG) based on the RRC connection reconfiguration message.

A method for receiving a radio resource control (RRC) message by a user equipment (UE) is described. The method includes receiving, from a base station, a radio resource control (RRC) connection reconfiguration message including data radio bearer (DRB) configuration parameters for remapping a DRB that is established on a master cell group (MCG), to a split DRB; and coupling a packet data convergence protocol (PDCP) that is established on the MCG to a radio link control (RLC) of the MCG and a RLC of a secondary cell group (SCG) based on the RRC connection reconfiguration message.