An enhanced handover procedure is provided to facilitate communication routing changes in an integrated access and backhaul (IAB) network. In an IAB network a network node can be connected to the core network via multiple different paths, and when the path changes, (e.g., when an intermediate network node performs a handover procedure with another network node), messages can be sent to relevant network nodes informing them of the route change so as to reduce the number of protocol data units (PDUs) that are transmitted to network nodes that are no longer part of the communication path to the target network node. The network node that is no longer part of the communication path can also inform a parent node of which PDUs have been successfully transmitted to the target network node so that the parent node can retransmit the PDUs that were not transmitted successfully.

An example method is provided in one example embodiment and may include maintaining a count of packets forwarded to a target evolved Node B (eNodeB) from a source eNodeB during a handover of a user equipment (UE) from the source eNodeB to the target eNodeB; and communicating an end marker indication message from the source eNodeB to the target eNodeB including the count of packets forwarded to the target eNodeB upon handover of the UE to the target eNodeB. A count of packets can be maintained for each bearer of the UE. A separate end marker indication message can be communicated to the target eNodeB for each bearer of the UE. The count of packets can be included in a Private Extension Information Element (IE) of the end marker indication message. In some embodiments, Radio Link Control (RLC) tuning parameters can be included in the Private Extension IE.

Some embodiments of this disclosure include systems, apparatuses, methods, and computer-readable media for the reduction of handover interruptions. Some embodiments include a user equipment (UE) that supports simultaneous connectivity with a source 5G Node B (gNB) and a target gNB during a handover. Some embodiments include the UE receiving source path data packets from the source gNB and target path data packets from a target gNB. The UE performs a first reorder of the one or more source path data packets and the one or more target path data packets by sequence number (SN), and the UE performs header decompression on the reordered source path data packets, separately from the reordered target path data packets. After the header decompressions the UE performs a second reorder of the source path data packets and the target path data packets together by SN, and discards any duplicate data packets based on SNs.

Certain aspects of the present disclosure provide a method for wireless communication at a wireless node, generally including communicating, via a first link, with a first access point (AP) device affiliated with a single mobility domain (SMD) entity, outputting, for transmission to the first AP device, a first message including a first indication that the wireless node is initiating a handover of the wireless node from the first AP device to a second AP device affiliated with the SMD entity, communicating with the second AP device via a second link during the handover after obtaining a second indication that context information has been transferred from the first AP device to the second AP device, and disabling the first link with the first AP device after obtaining a third indication that triggers the wireless node to disable the first link with the first AP device.

Described herein is a User Plane Function, UPF, network node, configured for data forwarding for selective activation of a Secondary Cell Group, SCG, for serving a User Equipment, UE, the UPF network node comprising: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the UPF network node at least to: receive an indication message for starting data forwarding; and execute data forwarding on the basis of the received indication message.

A user equipment (UE) and source base station may use data compression techniques for data packets sent between them. During a handover, the source base station may provide data compression context to a target base station, thus enabling the target base station to continue the data compression following the handover without having to reestablish the data compression context. The source base station may determine data compression capabilities of the UE or the target base station, or both, and may communicate the determined data compression capabilities to the UE or target base station. The source base station may identify at least one gap in a sequence of packets received from the UE, and communicate the existence of the gap to the target base station, which may request retransmission of packets associated with the gap.

A method for managing handover procedure in a radio access network (RAN) includes initiating, by a source base station, a handover procedure for a first user equipment with a target base station, wherein the first user equipment is connected to the source base station; identifying, by the source base station, a second user equipment that functions as a relay device, for relaying data related to the first user equipment from the source base station to the first user equipment during the handover procedure; establishing, by the source base station, a first connection between the identified second user equipment and the first user equipment; transmitting, by the source base station, buffered data corresponding to the first user equipment, to the target base station; transmitting, by the source base station, at least one block of data from the buffered data to the first user equipment, via the second user equipment, during the handover procedure for the first user equipment from the source base station to the target base station; and disconnecting, by the source base station, the established first connection between the second user equipment and the first user equipment, upon receiving a sequence number (SN) status request message from the target base station.

A radio network (6) and a radio terminal (4) are configured to, when the radio terminal (4) is using a first cell (10) served by a first radio station (1) as a primary cell and a second cell (20) served by a second radio station (2) as a secondary cell, change the primary cell from the first cell (10) to a third cell (30) served by a third radio station (3) while keeping communication status information regarding the radio terminal (1) on the second cell (20). It is thus, for example, possible to enable a communication service in the secondary cell to he continued even after the primary cell is changed when the primary cell is changed during execution of carrier aggregation (e.g., Inter-eNB CA) on a plurality of cells served by different radio stations.

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. A method for supporting handover and a corresponding base station and network node for performing the method is provided. The method includes forwarding data to a target base station, receiving a first end marker packet from a core network, and transmitting, for a quality of service, quality of service (QoS), flow for which the data forwarding has been completed, a second end marker packet to the target base station, the end marker packet containing a QoS flow identity (QFI). The methods of embodiments of the disclosure may reduce the packet transmission delay and improve the user experience.

An apparatus and method for performing procedures (protocols) of a PDCP (Packet Data Convergence Protocol) layer and an RLC (radio layer in an E-UMTS (Evolved Universal Mobile Telecommunications System) which has evolved from UMTS, among radio protocols of a mobile communication system. The PDCP layer performs ciphering on data (i.e., PDCP SDU) received from an upper layer, generates an indicator discriminating ciphered data and non-ciphered data (i.e., an ROHC feedback packet directly generated by the PDCP layer), and transmits the same to a lower layer (i.e., MAC layer). A PDCP SN (Sequence Number) is defined as an algorithm for ciphering the data in the PDCP layer to perform ciphering in the PDCP layer.