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) are provided. The communication method and system 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. A method, terminal, and base station for performing a random access procedure in a wireless communication system are provided. The terminal method includes, receiving, from a base station, a radio resource control (RRC) reconfiguration message including dedicated configuration information for an RA, identifying whether information on a maximum number for message A (MSGA) transmissions is configured in the dedicated configuration information, and in case that the information on the maximum number is configured in the dedicated configuration information, performing the RA procedure based on the information on the maximum number.

A method of configuring a set of active cells among neighboring cells to reduce latency and interruption for inter-cell mobility is proposed. The set of active cells is an active set of cells among which UE can do fast cell switching. The set of active cells is configured by the network based on UE measurement report or network deployment information. UE maintains the configuration and can perform pre-synchronization to the configured active cells in downlink (DL) only or in both DL and uplink (UL). UE maintains the DL/UL synchronization with the active cells, and applies configuration once UE is indicated to switch to an active cell as the target cell. Because UE maintains the configuration and DL/UL timing of the target cell before receiving the cell-switch command, the mobility latency and interruption time for inter-cell mobility is reduced.

Aspects of the subject disclosure may include, for example, receiving a notification from a serving base station regarding a communication device over a mobile network indicating discovery of a target base station, and obtaining a device type of the communication device and a first cell identifier of the target base station. Further embodiments include providing instructions to the serving base station to request the communication device to obtain a second cell identifier of the target base station, and obtaining the second cell identifier of the target base station from the serving base station over the mobile network. Additional embodiments include providing instructions to the serving base station to generate a communication link between the serving base station and the target base station based on the second cell identifier. Other embodiments are disclosed.

Various solutions for uplink synchronization in non-terrestrial network (NTN) communications are proposed. An apparatus implemented in a user equipment (UE) receives a system information block (SIB) of a target cell via a non-terrestrial (NT) network node of the NTN. The apparatus obtains an explicit epoch time from the SIB of the target cell. Then, the apparatus performs an uplink (UL) synchronization with the target cell through adjusting an uplink transmit time according to the explicit epoch time.

The present disclosure relates to a user equipment (UE) that comprises a receiver of the UE receives, from a source base station of a source radio cell, a common timing advance value for a target radio cell. The UE is connected to the source radio cell and is involved in a handover procedure to hand over the UE from the source radio cell to the target radio cell. Further, the common timing advance value is received from the source base station in a first message of the handover procedure, which also comprises a timing indication for transmitting a second message from the UE to the target base station. Then, a processor of the UE determines a first uplink timing of uplink transmissions to the target base station with respect to downlink transmissions from the target base station, based on the received common timing advance value and the timing indication. A transmitter of the UE transmits a second message of the handover procedure to the target base station based on the determined uplink timing. The processor determines a UE-specific timing advance value, specific to the UE and the target radio cell, to be used by the UE for performing uplink transmissions in the target radio cell.

Systems, methods, apparatuses, and computer program products for conditional handover (CHO) execution with network slice service continuity prioritization are provided. A radio resource control (RRC) reconfiguration message sent by a source radio access network (RAN) node to the user equipment (UE) may include, for each CHO configuration, an associated network slice-related priority index. The UE may take this index into account when selecting a suitable cell during CHO recovery. Additionally, or alternatively, the RRC reconfiguration message sent by a source RAN node may include, for each CHO configuration, an associated network slice support information of the candidate target cell. The message may also include network slice remapping information for any network slice associated with one of the candidate target cells. Using the above network slice-related information received from the network, the UE can prioritize the cell to select during CHO recovery in case more than one suitable cell is available.

Systems, methods, apparatuses, and computer program products for conditional handover (CHO) execution with network slice service continuity prioritization are provided. A radio resource control (RRC) reconfiguration message sent by a source radio access network (RAN) node to the user equipment (UE) may include, for each CHO configuration, an associated network slice-related priority index. The UE may take this index into account when selecting a suitable cell during CHO recovery. Additionally, or alternatively, the RRC reconfiguration message sent by a source RAN node may include, for each CHO configuration, an associated network slice support information of the candidate target cell. The message may also include network slice remapping information for any network slice associated with one of the candidate target cells. Using the above network slice-related information received from the network, the UE can prioritize the cell to select during CHO recovery in case more than one suitable cell is available.

The disclosure relates to a communication technique for converging a 5G communication system for supporting a higher data transfer rate beyond a 4G system with an IoT technology, and a system therefor. The disclosure may be applied to intelligent services based on a 5G communication technology and an IoT-related technology. A method of a terminal is provided that includes receiving, from a source base station, configuration information for a handover to a target base station, the configuration information including information on at least one of a first type random access procedure and a second type random access procedure, identifying a type of random access procedure based on the configuration information, and performing a random access procedure to the target base station based on the identified type.

A method by a user plane breakout function in a mobile core network for providing dynamic distributed local breakout. The method includes receiving, from one or more neighboring user plane breakout functions, service instance information of one or more instances of a service, processing capacity information of one or more edge clouds, and link quality information of one or more links between other user plane breakout functions. The method further includes, calculating, for each of the one or more instances of the service, a service instance access score for that instance of the service based on the service instance information, the processing capacity information, and the link quality information.

A technique for managing mobility configuration in a UE includes obtaining conditional configuration information including (i) a conditional configuration related to a candidate cell in the RAN, and (ii) a condition to be satisfied before the UE applies the configuration (1202). The technique further includes detecting that a non-conditional procedure related to the UE and the RAN has been initiated, when the UE is connected to the RAN via at least one cell (1204); determining, subsequently to the detecting and when the non-conditional procedure has not been completed, that the condition is satisfied (1206); and completing, by the processing hardware, (i) the conditional procedure in accordance with the conditional configuration and (ii) the non-conditional procedure (1208).