Abstract: 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.

Abstract: A method and apparatus for performing a L3 handover between CNs in a packet-switched network are provided. When a UE moves from an old RAN to a new RAN, the UE sends a measurement report message including cell information to the old RAN. The old or new RAN determines whether to perform a L3 handover. If the L3 handover is required, a tunnel is established between the new RAN and a new CN. The UE performs a handover from the old RAN to the new RAN, without establishing a tunnel between the new RAN and an old CN. Upon detection of the movement of the UE, the new RAN sends a L2 handover complete message to the old RAN. After moving to the new RAN, the UE acquires a new IP address, performs the L3 handover, and communicates with the new CN through the new RAN.

Abstract: A method and apparatus for transmitting and receiving CQI in a wireless communication system are provided.

Abstract: A method and apparatus for performing a L3 handover between CNs in a packet-switched network are provided. When a UE moves from an old RAN to a new RAN, the UE sends a measurement report message including cell information to the old RAN. The old or new RAN determines whether to perform a L3 handover. If the L3 handover is required, a tunnel is established between the new RAN and a new CN. The UE performs a handover from the old RAN to the new RAN, without establishing a tunnel between the new RAN and an old CN. Upon detection of the movement of the UE, the new RAN sends a L2 handover complete message to the old RAN. After moving to the new RAN, the UE acquires a new IP address, performs the L3 handover, and communicates with the new CN through the new RAN.

Abstract: A method and apparatus for performing a L3 handover between CNs in a packet-switched network are provided. When a UE moves from an old RAN to a new RAN, the UE sends a measurement report message including cell information to the old RAN. The old or new RAN determines whether to perform a L3 handover. If the L3 handover is required, a tunnel is established between the new RAN and a new CN. The UE performs a handover from the old RAN to the new RAN, without establishing a tunnel between the new RAN and an old CN. Upon detection of the movement of the UE, the new RAN sends a L2 handover complete message to the old RAN. After moving to the new RAN, the UE acquires a new IP address, performs the L3 handover, and communicates with the new CN through the new RAN.

Abstract: A method and apparatus for transmitting and receiving CQI in a wireless communication system are provided.

Abstract: A method and apparatus for transmitting and receiving CQI in a wireless communication system are provided, in which when a UE transitions from a continuous reception state to a DRX state, CQI report resources are reallocated to the UE according to a CQI report resource reallocation rule agreed between the UE and an E-RAN, which obviates the need for signaling information about allocated new CQI report resources.

Abstract: This invention relates to the area of Mobility and Handover between heterogeneous wireless networks. The scope of the invention also covers the case when the UE is capable of accessing both the WLAN and EUTRAN access systems simultaneously and also the case where the UE is not capable of accessing both the WLAN and EUTRAN access systems simultaneously. This invention provides a system and method to perform Mobility between the access systems with optimized authentication procedure using security context transfer between the access systems and also minimize the data loss by buffering the data during the handover. More specifically, this invention provides a system and method to support handover between the I-WLAN and the EUTRAN access systems.

Abstract: A method for controlling a rate of a voice service in a mobile communication system supporting the voice service via a packet network. The method includes the steps of receiving a control message at a terminal from a radio network controller (RNC); if the control message indicates control of a downlink rate, determining a downlink rate according to the control message; setting a Change Mode Request (CMR) field of an uplink Voice over Internet Protocol (VoIP) packet according to the downlink rate, and transmitting the uplink VoIP packet from the terminal to the RNC; if the received control message indicates control of an uplink rate, determining an uplink rate according to the control message; and generating an uplink VoIP packet including uplink voice data generated according to the determined uplink rate and frame type (FT) information indicating the determined uplink rate, and transmitting the uplink VoIP packet from the terminal to the RNC.

Abstract: 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.

Abstract: A method for controlling a rate of a voice service in a mobile communication system supporting the voice service via a packet network. The method includes the steps of receiving a control message at a terminal from a radio network controller (RNC); if the control message indicates control of a downlink rate, determining a downlink rate according to the control message; setting a Change Mode Request (CMR) field of an uplink Voice over Internet Protocol (VoIP) packet according to the downlink rate, and transmitting the uplink VoIP packet from the terminal to the RNC; if the received control message indicates control of an uplink rate, determining an uplink rate according to the control message; and generating an uplink VoIP packet including uplink voice data generated according to the determined uplink rate and frame type (FT) information indicating the determined uplink rate, and transmitting the uplink VoIP packet from the terminal to the RNC.

Abstract: A method and terminal apparatus for transmitting a status report comprising a received status of packet data in a mobile communication system are provided, in which whether transmission of an implicit Negative Acknowledge (NACK) signal is required for requesting retransmission of at least one non-received data packet whose sequence number is unidentified is determined, if transmission of the implicit NACK signal is required, the implicit NACK signal including a sequence number of the last packet is generated among successfully received data packets, and a status report including the implicit NACK signal is transmitted to the transmitter, and if transmission of the implicit NACK signal is not required, a status report is transmitted to the transmitter including at least one of an ACK signal comprising a sequence number of a successfully received data packet and an explicit NACK signal comprising a sequence number of a non-received data packet whose sequence number is identified.

Abstract: Disclosed is a method and system for mutually exchanging capability information of UEs for communication between a Circuit-Switched (CS) and IMS services (CSI) UE, which can use a CS call for voice communication while using an IMS session for PS service, and an IMS UE which uses an IMS session for both voice communication and PS service. A MGCF performs interworking of capability information between a CS message and an IMS message so that the IMS UE can process UE capability information through an IMS session request/response. When a call request message containing no capability information is created from a UE not supporting capability exchange, a CSI AS transfers the call request message to a peer UE after inserting estimable capability information of the UE into the call request message, and stores capability information of the counterpart UE for the UE.

Abstract: Provided is a handover method, in which a call manager of a network having a Circuit Switching (CS) network, a Long Term Evolution (LTE) network, and an Internet Protocol Multimedia Subsystem (IMS) network, provides handover, from the LTE network to the CS network, to a terminal that uses one radio channel. The handover method includes upon receiving a request for handover from the terminal via a node of the LTE network, establishing a line to a Mobile Switching Center (MSC) of the CS network; sending, to the call manager, a request for a change in a session to another party's terminal in communication with the terminal, to establish an Internet Protocol (IP) bearer between the call manager and the other party's terminal; and sending a handover command to the terminal during the establishment of an IP bearer, to establish a radio channel to the base station of the CS network.

Abstract: Disclosed is a method and system of deriving new keys for accessing a new system. The method enables an optimized authentication procedure during handover form an existing system to a new system by using the existing system access keys. The user equipment that is accessing the new system receives a temporary ID during handover preparation which enables the user equipment to perform a fast re-authentication. The method uses existing system access keys to derive system access keys for the new network.

Abstract: This invention relates to the area of Mobility and Handover between heterogeneous wireless networks. The scope of the invention also covers the case when the UE is capable of accessing both the WLAN and EUTRAN access systems simultaneously and also the case where the UE is not capable of accessing both the WLAN and EUTRAN access systems simultaneously. This invention provides a system and method to perform Mobility between the access systems with optimized authentication procedure using security context transfer between the access systems and also minimize the data loss by buffering the data during the handover. More specifically, this invention provides a system and method to support handover between the I-WLAN and the EUTRAN access systems.

Abstract: A method and apparatus are provided for transmitting a Session Initiation Protocol (SIP) message by a User Equipment (UE) in an idle mode in an Internet Protocol Multimedia Subsystem (IMS) system. The UE transmits one combined message of an AS control message and a NAS control message including information indicating transmission of an SIP message, thereby having an effect on an upper node to reduce a delay due to message processing.

Abstract: 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.

Abstract: An efficient uplink timing synchronization procedure performed with a target cell upon handover of a User Equipment (UE) in active mode in a mobile communication system is provided, in which a cell transmitter signals to the UE that the uplink timing synchronization procedure is not required in the target cell, and the UE carries out uplink transmission to the target cell at an uplink timing used in a source cell without the uplink timing synchronization procedure.

Abstract: 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.