Samsung Electronics Co., Ltd.

Korea Advanced Institute of Science and Technology

Jin-Youn Cho

Kyung-Hun Jang

Chang-Woo Seo

Hyo-Sun Hwang

Dong-Ho Cho

Dong-jun Lee

Ki-Ho Lee

Sung-Jea Ko

Sang-Hyun Woo

Tae-Soo Kwon

Jin-Bong Chang

Ae-Ri Lim

Choong-hun Lee

Chun-su Park

Rae-Jin Uh

Ki-Hyun Pyun

Jin-bong Chang

Jin-Bong Cahng

Gang-Youl Yu

Kyung-Ho Hwang

A terminal location estimation method in a wireless communication system in which an access point (AP) provides an access service to a plurality of terminals includes defining a plurality of beam spaces around the AP through space multiplexing; scheduling the beam spaces according to a predetermined pattern; simultaneously forming a beam in at least one beam space; and detecting the existence and location of a terminal according to whether a response message in response to the formed beam is received. Accordingly, an AP forms beams in a predetermined scheduling pattern, and each of the terminals detecting the beams registers its location by informing the AP that each of the terminals exists in a relevant beam area, and thus, a location of each of the terminals can be estimated without using a complex DOA algorithm.

Method of estimating location of terminal in switched-beamforming based wireless communication system

A method and apparatus controls power consumption of stations having a hierarchical structure when the stations transmit and receive a wireless signal to and from one another on a CSMA/CA wireless LAN. The controlling involves extracting information on frame transmission speed and transmission period information on first and second layers of the hierarchical structure from the wireless signal; determining a power-controlled period for each of the first and second layers based on the extracted information; and reducing the power consumption of the first and second layers by switching a current mode of the first and second layers to a predetermined mode for the power-controlled period if a reception address included in the extracted information is not identical to an address of the station.

Method and apparatus for controlling power consumption of stations on a CSMA/CA-based wireless LAN

Local communication system in wireless communication system includes a main wireless terminal negotiating with each of the peripheral wireless terminals during a time period for which a frame will be transmitted, generating a schedule map including negotiated time information and a transmission sequence of each of the peripheral wireless terminals, and transmitting the generated schedule map to all peripheral wireless terminals; and the peripheral wireless terminals storing the schedule map received from the main wireless terminal, and performing communication with the main wireless terminal according to the sequence determined in the schedule map for the negotiated time period.

Local communication system and method in wireless communication system

A Medium Access Control (MAC) apparatus and method for use in a channel overlay network of a wireless access system. The wireless access system, which is based on a multi-carrier, includes a plurality of physical modules for receiving signals from a plurality of terminals, a plurality of MAC (Medium Access Control) modules for processing the signals received via the physical modules while being classified according to predetermined traffic classes, and a controller connected to the MAC modules for integratedly managing the MAC modules. The MAC apparatus includes an additional MAC module used for a control channel and a plurality of MAC modules for supporting various QoS traffic data according to individual classes, thereby improving scheduling complexity in a MAC layer.

Medium access control apparatus for use in a channel overlay network

A method for transmitting data at a high rate in a wireless LAN is provided. A wireless access point requests reliable node information from a wireless terminal having a transfer rate equal to or less than a predetermined transfer rate if data to be transmitted to the terminal occurs. The terminal produces a frame containing information related to reliable nodes that can communicate with the terminal and information of greatest transfer rates between the reliable nodes and the terminal, and transmits the frame to the access point. The access point selects an optimal relay node from the reliable nodes, based on the greatest transfer rates between the reliable nodes and the access point and transfer rates between the reliable nodes and the terminal, and determines if a relay gain exists when using the optimal node. If the relay gain exists, the access point performs relay transmission to the terminal; otherwise, it performs direct transmission to it.

Method for transmitting a frame at a high rate in a wireless local area network

A handoff method is provided in a communication network including a plurality of fixed nodes attached to a router connected to at least one external network, and at least one mobile node associated with a current fixed node. The method detects movement of a mobile node; prepares a handoff of the mobile node from a current fixed node to potential fixed nodes upon detecting movement of the mobile node; decides whether to handoff to one of the potential fixed nodes as a target fixed node; and performs the handoff from the current fixed node to the target fixed node. The handoff method enables the mobile station to quickly move its association from one access point to another by minimizing a probe delay which is a primary contributor to handoff delay.

Seamless handoff method in wireless local area network

An HARQ method for guaranteeing a QoS in a wireless communication system is provided. In a transmitting apparatus using a HARQ for transmitting packet data in a wireless communication system, a retransmission controller determines the size of redundancy information for correcting transmission errors in packet data, and a transmitter transmits the redundancy information of the determined size upon request for a retransmission of the packet data. Transmission of redundancy information of a variable size at each retransmission satisfies the QoS required for each user, maximizes a data throughput, and allows for the efficient reception of an ACK or a NACK for the redundancy information.

HARQ method for guaranteeing QoS in a wireless communication system

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Seoul, South Korea

Jin-Youn Cho