The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method performed by a first node in a wireless communication system, including receiving, from a second node, downlink user data through a first radio bearer, the downlink user data including multicast service data; transmitting, to at least one UE, the downlink user data through a second radio bearer; and transmitting, to the second node, a downlink data delivery status including PDCP sequence number information, wherein the PDCP sequence number information includes a higher PDCP sequence number between a highest PDCP sequence number successfully delivered in sequence associated with a first transmission mode and a highest PDCP sequence number transmitted to lower layers associated with a second transmission mode.

The present 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 present 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. According to an aspect of the embodiments of the present disclosure, a method for supporting handover is provided, comprising: receiving a message from a central unit control plane entity of a target base station; receiving a data packet from a source base station; and discarding a packet data convergence protocol (PDCP) service data unit (SDU) including the PDCP sequence number (SN) in the received data packet according to the indication of the message. The problem of coordinated work between the source base station and the target base station during the handover process may be solved. Especially when the source base station and/or the target base station support the separation of the control plane and the user plane, ensure that the central unit control plane entity of the source base station, the central unit user plane entity of the source base station, the central unit control plane entity of the target base station and/or the central unit user plane entity of the target base station may fully coordinately work.

This disclosure describes systems, methods, and devices related to multi-link devices (MLDs). A MLD may identify a first security key received from a first access point MLD (A-MLD); identify a second security key received from the first A-MLD; transmit, from a first physical location, a first packet to the first A-MLD, the first packet including the first security key; identify a first subset of N packets, the first subset received from the first A-MLD; transmit, from a second physical location, a second packet to the second A-MLD, the second packet including the second security key; identify a second subset of the N packets, the second subset received from the second A-MLD; determine that a third packet of the N packets was not received; and transmit, to the first A-MLD or the second A-MLD, an indication that the third packet was not received.

The present 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 present 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. According to an aspect of the embodiments of the present disclosure, a method for supporting handover is provided, comprising: receiving a message from a central unit control plane entity of a target base station; receiving a data packet from a source base station; and discarding a packet data convergence protocol (PDCP) service data unit (SDU) including the PDCP sequence number (SN) in the received data packet according to the indication of the message. The problem of coordinated work between the source base station and the target base station during the handover process may be solved. Especially when the source base station and/or the target base station support the separation of the control plane and the user plane, ensure that the central unit control plane entity of the source base station, the central unit user plane entity of the source base station, the central unit control plane entity of the target base station and/or the central unit user plane entity of the target base station may fully coordinately work.

A communication control method is used in a mobile communication system for providing a multicast broadcast service (MBS) from a base station to user equipment, and includes receiving, by the base station from a core network or another base station, a specific Packet Data Convergence Protocol (PDCP) sequence number specified to be applied to an MBS packet; associating, by the base station, the MBS packet with the specific PDCP sequence number; and transmitting, by the base station to the user equipment, the MBS packet associated with the specific PDCP sequence number.

Embodiments of this application provide a data processing method and a related device. In the method, a radio link control RLC entity in a network device receives a first data packet corresponding to a first sequence number SN from a terminal device. The RLC entity determines, based on the first SN and a second SN, whether the first SN jumps abnormally, where the second SN is an SN of any data packet received before a current moment. The RLC layer entity may determine whether the SN jumps abnormally, to perform a subsequent operation such as handover, thereby reducing occurrence of a one-way audio event.

A method is provided, including: configuring a conditional candidate primary secondary cell group cell PSCell addition or change for a terminal device; and performing, by a master network device, early data transmission oriented to a network device to which a candidate PSCell belongs, and for example, before the terminal device accesses the candidate PSCell, sending a data packet to the network device to which the candidate PSCell belongs, where a form of the data packet is a packet data convergence protocol protocol data unit, and the data packet includes a data packet on an MN terminated secondary cell group bearer and/or a data packet on an MN terminated split bearer. In this way, after the terminal device accesses a candidate network device, the candidate network device may send forwarded data to the terminal device, to reduce a data transmission delay.

Embodiments of the present disclosure relate to methods, devices and computer readable media for communications. A method comprises receiving, at a terminal device and from a network device, a first message indicative of a switching condition for the terminal device to switch to a second service providing mode, the terminal device being served by the network device in a first service providing mode. The method further comprises: in accordance with a determination that the switching condition is satisfied, establishing a connection with the network device to be served by the network device in the second service providing mode. In this manner, a dynamic and efficient switching process between multicast mode and unicast mode can be autonomously triggered at the terminal device.

The disclosure is directed to an RLC SDU transmission method, and an IAB node using the same method. In as aspect, the RLC SDU transmission method is used by a first IAB node and includes: receiving a control signal from an IAB donor node; identifying a stray RLC SDU destined for the UE, associated with a sequence number, and not acknowledged by the second IAB node in response to receiving the control signal; and transmitting an RLC PDU to the second IAB node to inform the second IAB node of the stray RLC SDU.

A buffer control method, a network element, and a system. The method includes: receiving, by a network element, a flow table message from a controller, where the flow table message includes buffer information of a data packet matching a flow table; processing, by the network element, a buffer of the data packet based on the buffer information, and sending a flow table response message to the controller. In the method, the network element can save, based on a corresponding saving manner, at least one data packet matching the flow table to the buffer corresponding to the flow table. Thus a data flow granularity-based buffer processing manner can be supported in an OpenFlow protocol, and a data buffering requirement of a mobile network can be met.