Electronics and Telecommunications Research Institute

Samsung Electronics Co., Ltd.

Sk Telecom Company, Ltd.

Kt Corporation

Ktfreetel Co., Ltd

Hanaro Telecom., Inc.

Curitel Communications, Inc.

Ae-Soon Park

Jae Wook Shin

Kwang-Ryul Jung

Mi Jeong Yang

Sung-Min Oh

Soon-Yong Lim

Seok-Heon Cho

Kyung-Soo Kim

Chul-Sik Yoon

Changhee Lee

Wooram Shin

Hyun Seo Park

Jee Hwan Ahn

Jee-Hwan Ahn

Pyeong Jung Song

Yeong-Jin Kim

Soon Yong Lim

Hyun-Seo Park

Sook-Yang Kang

JaeSheung Shin

Kwang Ryul Jung

Nak-Woon Sung

Sun-Hwa Lim

Eunah Kim

Jeong Hwan Lee

Kyung-Yul Cheon

Mi-Jeong Yang

Jae-Wook Shin

You-sun Hwang

Sook Yang Kang

Hye-Yeon Kwon

There are provided a method for processing an exceptional case of establishing a default bearer and a device therefor in order to solve a problem in that a user equipment cannot actually receive an IP service by accessing a packet network while failing in establishing the default bearer in a mobile communication system. A method for processing an exceptional ease of establishing a default hearer in a mobility management entity includes: receiving a network attachment request from a user equipment; transmitting a network attachment acceptance including an activation request of the default bearer to the user equipment in response to the network attachment request; and cancelling a network attachment procedure when a completion response to the activation request of the default bearer is not received from the user equipment within a predetermined time.

Method for processing exceptional case of establishing default bearer in mobile communication system and device therefor

There are provided a method for processing an exceptional case of establishing a default bearer and a device therefor in order to solve a problem in that a user equipment cannot actually receive an IP service by accessing a packet network while failing in establishing the default bearer in a mobile communication system. A method for processing an exceptional case of establishing a default bearer in a mobility management entity includes: receiving a network attachment request from a user equipment; transmitting a network attachment acceptance including an activation request of the default bearer to the user equipment in response to the network attachment request; and cancelling a network attachment procedure when a completion response to the activation request of the default bearer is not received from the user equipment within a predetermined time.

A method for synchronization by a D2D terminal in a D2D communication network through receiving a first D2D synchronization signal from at least one D2D synchronization source and performing synchronization according to a synchronization timing reference provided through the first D2D synchronization signal, and a method for negotiating whether to perform a role as a synchronization source with another D2D synchronization source through determining, when a D2D synchronization signal and a D2D synchronization channel are received from at least one D2D synchronization source, whether to maintain a role as the independent synchronization source based on negotiation information for negotiation between synchronization sources included in the D2D synchronization channel, and operating as a relaying synchronization source when the role as the independent synchronization source is not maintained, are provided.

Method and apparatus for synchronization in D2D communication network

A method and apparatus for handover is provided. In a network environment in which a plurality of beams are provided within a base station, a terminal measures signal strength of a serving beam and signal strength of a target beam and transmits a measurement report message when a first condition or a second condition is satisfied. The base station determines inter-beam coordinated scheduling when the signal strength of the serving beam and target beam satisfy the first condition, and determines handover between beams when the signal strength of the serving beam and target beam satisfy the second condition. The base station transmits a message for commanding handover to the terminal when the handover between beams is determined. The terminal then stops communicating with the serving beam and performs handover to the target beam.

Method and apparatus for handover

A UE does not immediately perform handover after receiving a handover command from a serving base station, but instead backups that message and continuously compares the signal strength of a serving base station and the signal strength of a target base station and performs a handover to the target base station at the best timing when handover is required. Once the timing of handover is determined, the UE transmits a handover indication message to the serving base station, and thereafter the UE performs a handover to the target base station.

Handover method and apparatus

Disclosed are a method for requesting, generating and distributing a service-specific traffic encryption key in a wireless portable Internet system, an apparatus for the same, and a protocol configuration method for the same. In the present invention, a subscriber station sends a Key Request message for requesting a service-specific traffic encryption key to the base station using a PKM-REQ MAC message, and a base station analyzes the Key Request message to generate the requested service-specific traffic encryption key. Subsequently, the base station sends a Key Reply message, including the generated service-specific traffic encryption key, to the subscriber station using a PKM-RSP MAC message. If the base station fails to generate the key, the base station sends a Key Reject message, including a reason for the failure, to the subscriber station.

Method for requesting, generating and distributing service-specific traffic encryption key in wireless portable internet system, apparatus for the same, and protocol configuration method for the same

User equipment and a base station in a carrier aggregation system, and a call admission method thereof are discussed. The user equipment includes multiple physical layers, and the base station provides multiple component carriers. When messages for connection setup are transmitted and received between the user equipment and base station, the messages may include information about what component carriers are selected for the physical layers, information about what component carriers are selectable for the physical layers, information about calculations for uplink timing alignment. Call admission control and load balancing may be performed based on the information included in the messages. Accordingly, a carrier aggregation system providing call admission and load balancing is achieved.

User equipment and base station in carrier aggregation system, and call admission control method for use with the user equipment and base station

A method for controlling uplink IP packet filtering in a mobile terminal in a 3GPP Evolved Packet System (EPS) is provided, including an information receiving operation of receiving IP address information allocated to user equipment, and filtering information required for delivering an uplink IP packet received from the user equipment; and a filtering operation for determining which packet data network and a bearer the IP packet is delivered to, based on the IP address information and the filtering information. In a 3GPP evolved packet system supporting a default bearer function, a packet data network to which an uplink IP packet is delivered and a bearer identifier can be efficiently determined when the user equipment simultaneously accesses one or more packet data networks and is allocated several IP addresses, resulting in effective uplink packet filtering.

Method of uplink IP packet filtering control in mobile terminal

A method is provided for managing a tunnel when a mobile node moves from an existing visiting network to a visiting network which supports a mobile IP. A mobile node may detect a movement of the mobile node, configure a care-of address (CoA) and thereafter transmit a location registration (Binding Update) message to a home agent. The mobile node may create a second tunnel in the visiting network and set the second tunnel as a receiving-only tunnel while maintaining a first tunnel which is already used in the existing visiting network. The mobile node may receive a location registration completion (Binding Acknowledgement) message from the home agent, change the second tunnel to the tunnel capable of transmitting/receiving by modifying a routing table, and cancel the first tunnel.

Tunnel management method and apparatus for reducing packet losses of mobile node in mobile IP environment

Provided are an inter-carrier member handover apparatus and method. In the inter-carrier member handover apparatus and method, data is transmitted or received by allocating a plurality of carriers to a single mobile terminal, a carrier aggregation, which includes a plurality of carrier members that process the allocated carriers, is managed, and a handover between the carrier members in the managed carrier aggregation is processed when the handover is required. Therefore, an intra-base station handover can be performed when a mobile terminal and a base station exchange data using a plurality of carrier frequency bands.

Inter-carrier member handover apparatus and method

The present invention relates to a multi-mode communication system and a method thereof. The multi-mode communication system uses a first mode among a plurality communication modes for accessing a first mobility control entity (MCE) among a plurality of MCEs, and communicates data with the first MCE. The multi-mode communication system receives a paging request that has been transmitted from a multi-mode control entity (MMCE) for accessing a second MCE from the first MCE and analyzes the paging request, and puts the first mode into a sleep mode and a second mode for accessing the second MCE into an awake mode based on the analysis. Subsequently, multi-mode UE accesses the second MCE by using the second mode in the awake mode. According to the present invention, an MMCE for multi-mode control is provided to integrate and manage an idle state for each access mode of multi-mode user equipment, thereby minimizing power consumption due to access of the multi-mode UE to a radio access system. In addition, a change of the access of the multi-mode UE to the radio access system due to a paging request can be efficiently performed.

Multi-mode communication system and method thereof

The present invention relates to a handover method between systems of a multi-mode terminal. A multi-cast based protocol is added to an Internet protocol (IP) based wireless network to cooperate with the wireless access protocol of the terminal. In addition, minimized processes are added to use the wireless access protocol having wide area coverage. Accordingly, the handover between the systems may be performed while packet loss or service delay caused by a movement of a user may be minimized, and terminal complexity may not be increased.

Handover method between systems of multi-mode terminal

Disclosed are a subscriber station authentication method, a protocol configuration method, and a device thereof in a wireless portable Internet system. In the subscriber station authentication method, an authentication mode between a subscriber station () and a base station () is negotiated, and the authentication mode is negotiated by the base station () according to the authentication mode negotiation. The authentication modes include an authentication mode based on the IEEE 802.16 privacy standard protocol and an authentication mode based on the standardized authentication protocol of the upper layer. Authentication is performed by the base station () in the case of the authentication mode based on the IEEE 802.16 privacy standard protocol, and the authentication is performed through message transmission using a diameter protocol between a base station () and an authentication server () in the case of the authentication mode based on the standardized authentication protocol of the upper layer.

Growing community of inventors

Daejeon, South Korea

Ae-Soon Park