Samsung Electronics Co., Ltd.

Yonsei University

OSok Song

Sung-Ho Choi

Han-Na Lim

Eun-Hui Bae

Tae-Sun Yeoum

Gert Jan Van Lieshout

Himke Van Der Velde

Soeng-hun Kim

Kyung-Min Kim

Jai-Yong Lee

Hyun-Duk Jung

A method for transmitting packet data units Packet Data Units (PDUs) at a PDU transmitter in a communication system is provided. The method includes transmitting a first PDU comprising a PDU header and a data portion, receiving Negative Acknowledgement NACK information for the first PDU, segmenting the first PDU to form one or more PDU segments if a size of a second PDU for retransmission is smaller than a size of the first PDU, wherein each of the one or more PDU segment comprises a PDU segment header and a data portion, and transmitting the one or more PDU segment to a PDU receiver.

Method and apparatus for transmitting and receiving status report comprising received status of packet data in a mobile communication system

A method and apparatus is provided for communication between a first terminal capable of using both a Circuit Switched (CS) call and an Internet Protocol Multimedia Subsystem (IMS) session, and a second terminal capable of using the IMS session, in a communication system supporting a Combined CS call and IMS session (CSI service). If the second terminal sends a Session Initiation Protocol (SIP) request (INVITE) message to originate a voice service or a multimedia service including the voice service with the first terminal, a CSI Application Server (AS) of an IMS domain managing the first terminal separates a voice service-related component included in the request message from a multimedia service-related component, and generates and sends first and second request messages to the first terminal. Upon receipt of first and second response messages corresponding to the first and second request messages from the first terminal, the CSI AS generates a combined response message and sends the combined response message to the second terminal.

Method and apparatus for interworking voice and multimedia services between CSI terminal and IMS terminal

A method and system in which upon occurrence of a P-CSCF failure, a network sends an IMS reregistration request message to a UE. An S-CSCF or an AS monitors a P-CSCF to detect occurrence of a failure in the P-CSCF. Upon detecting the occurrence of a P-CSCF failure, the S-CSCF or the AS sends a request message for IMS reregistration to the UEs being served by the failed P-CSCF. In this manner, the UE can continuously receive the service even though a failure occurs in the P-CSCF.

IMS reregistration method and system therefor

A method and apparatus are provided for handing over from a Long Term Evolution (LTE) network to a Circuit Switching (CS) network by a call manager in a wireless communication system. The method includes receiving, from an Enhanced Node B (ENB) of the LTE network, a handover required message for a Packet Switching (PS) to CS handover from the LTE network to the CS network, when the PS to CS handover is decided based on measurement reports of a User Equipment (UE); sending, to a Mobile Switching Center (MSC) of the CS network, a PS to CS handover request message including an International mobile subscriber identity (IMSI) for identifying the UE and a target IDentifier (ID) for a target cell of the CS network; receiving a PS to CS handover response message from the MSC; and sending, to the UE via the ENB, a handover command message.

Handover apparatus and method in a heterogeneous wireless communication system

Growing community of inventors

Suwon-si, South Korea

OSok Song