A UE receives a handover command from a source eNB, and transmits a handover indication message to the source eNB while maintaining a connection to the source eNB. After transmitting the handover indication message, the UE disconnects the connection to the source eNB. Further, the UE accesses to a target eNB. A handover command includes information indicating timing advance if a handover without a random access procedure is configured.

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.

A method and an apparatus for synchronized handover in a mobile communication system are provided. A source base station providing data to a terminal transmits a handover command message for handover to a target base station to the terminal, and interrupts transmission of data to the terminal when the source base station receives a message for informing a handover execution timing from the terminal later. In addition, the source base station forwards data on the terminal to the target base station.

A communication control system, user terminal, and processor for controlling a user terminal in which a user terminal controls communication by using a first data bearer and a second data bearer, where the first data bearer does not pass through a Wireless Local Area Network (WLAN), but passes through the cellular base station, and the second data bearer passes through the WLAN and the cellular base station. The cellular base station controls communication with the user terminal by using the first data bearer and the second data bearer. The user terminal receives information transmitted from the cellular base station, where the information is for the user terminal to transmit a status report indicating a delivery status regarding data received via the WLAN and data directly received from the cellular base station. The user terminal transmits the status report to the cellular base station on a basis of the information.

User equipment (UE) handover (HO) techniques for reducing or eliminating interruption time during an HO process are described. In one embodiment, for example, an apparatus may include at least one memory and logic for an evolved node B (eNB), at least a portion of the logic comprised in hardware coupled to the at least one memory. The logic may be operative to forward downlink (DL) data received from a serving gateway (SGW) to user equipment (UE), transmit a handover command to the UE to trigger execution of a handover (HO) process to handover the UE to a target eNB, continue forwarding at least a portion of the DL data to the UE following transmission of the handover command, and terminate transmission of the DL data to the UE responsive to detecting a stop DL data event. Other embodiments are described and claimed.

Embodiments of a Next Generation Node-B (gNB) and methods of communication are disclosed herein. The gNB may be configurable to operate as a source gNB (S-gNB). The S-gNB may transfer, from a control plane (CU-CP) of the S-gNB to a CU-CP of a target gNB (T-gNB), an XnAP handover request message that indicates an Xn handover of a User Equipment (UE) from the S-gNB to the T-gNB. The S-gNB may initiate data forwarding, from a user plane (CU-UP) of the S-gNB to a CU-UP of the T-gNB, of downlink data packets. The data forwarding may be terminated based on reception of end marker packets from a user plane function (UPF) entity. The CU-UP of the S-gNB may transfer end marker packets to the CU-UP of the S-gNB to indicate termination of the data forwarding.

A wireless communication system, a mobile station, a base station, and a wireless communication method that improve communication efficiency between wireless communication stations are provided. A wireless communication apparatus includes a communication unit, which includes a first logical processing subject and a second logical processing subject that operates in association with the first logical processing subject and which performs multiple communications with a wireless communication apparatus, and includes a notifying unit that notifies the wireless communication apparatus of data related information. The wireless communication apparatus includes a second communication unit that transmits data, and a notifying unit that receives the data related information from the controller and controls an amount of data transmitted by the second communication unit.

A network comprising a first BS and a second BS for handling a handover comprises at least one storage device storing instructions of: the first BS transmitting a first RRC message configuring a DRB on a SRB to a communication device; the first BS receiving a first RRC response message on the SRB; the first BS receiving a first plurality of PDCP SDUs; the first BS performing a handover preparation procedure with the second BS for the communication device; the first BS transmitting a second RRC message on the SRB to the communication device; the second BS receiving a second RRC response message on the SRB; the first BS transmitting at least one of a RX_NEXT, a RX_DELIV and a RX_REORD; the second BS receiving a second plurality of PDCP SDUs; and the second BS processing the second plurality of PDCP SDUs according to the at least one.

In a method for transferring packet data remaining in a first SeNB to a second SeNB via an MeNB, use of a communication line is inefficient. A base station in a communication system that includes a master cell base station, a secondary cell base station, a core network, and a terminal device, wherein: the base station has a reception unit for receiving, from the master cell base station, downlink user data received from the core network by the master cell base station, and a transmission unit for transmitting the downlink user data received to the terminal device; the reception unit receives, from the master cell base station, switching information indicating that the base station from which the master cell base station receives downlink user data is to be switched; and the transmission unit transmits remaining data to the secondary base station when the reception unit has received the switching information.

A method is disclosed for avoiding unnecessary keepalive data transfers, comprising: receiving, at an upstream TCP connection endpoint in a radio access network (RAN) from an operator core network, an Internet Protocol (IP) packet; performing, at the upstream TCP connection endpoint, shallow packet inspection on the IP packet; and forwarding the IP packet to the downstream TCP connection endpoint in the RAN if the IP packet is not a keepalive packet, based on the performed shallow packet inspection. The upstream TCP connection endpoint in the RAN may be one of a nodeB, an eNodeB, a base transceiver station (BTS), a coordinating server, and a mobile edge computing (MEC) gateway. The downstream TCP connection endpoint in the RAN may be one of the nodeB, the eNodeB, or the base transceiver station (BTS).