Electronics and Telecommunications Research Institute

Other

Yonsei University

Seong Soon Joo

Jong Suk Chae

Wun Cheol Jeong

Anseok Lee

Chang Sub Shin

Cheol Sig Pyo

Tae Joon Park

So Young Hwang

Byung Sun Lee

Tae Rim Park

Kee Seong Cho

Bong Soo Kim

Se Han Kim

Ho Yong Kang

Jong Arm Jun

Jeong Dong Ryoo

Hoon Jeong

Jae Hong Ruy

Myung Jong Lee

Kyo Hoon Son

Moon Kyun Oh

Jong Jun Park

Kang Yong Lee

Jong Moon Chung

Mi S Han

Ki Yong Jin

Provided are an infrastructure apparatus and method of providing collaboration between thing devices. Since a plurality of thing devices located in a specific space share an experience where the plurality of thing devices have performed a collaboration service, each of the thing devices may search for peripheral thing devices for performing the collaboration service without intervention of a center server and may generate a collaboration group including the found thing devices, and tasks for performing through negotiation may be autonomously distributed to the thing devices included in the collaboration group, thereby providing autonomous collaboration between the thing devices.

Infrastructure apparatus and method of providing collaboration between thing devices

Provided is a personal content providing system for providing customized content according to a personalization context. The personal content providing system includes a context reader configured to receive a context beacon including the personalization context from one or more of a context terminal and a context tag, a content generation device configured to generate personal content, based on the personalization context, a content service device including a content output device that outputs the generated personal content, a local space switch configured to connect the context terminal, the context tag, the context reader, and the content service device which are disposed in a predetermined local space, and an infrastructure management device configured to manage the context terminal, the context tag, the context reader, and the content service device which are disposed in the predetermined local space.

System and method of providing personal content

A super frame structure supporting a mesh network, and a beacon scheduling method. The super frame structure and the beacon scheduling method may support a mesh topology in a beacon enabled mode, may have an algorithm that is simple and easily realized via beacon scheduling using a distribution method, and may easily adapt to changes in a network environment.

Super frame structure and beacon scheduling method for mesh networking

A constant amplitude decoding apparatus and method for multiplexed direct-sequence spread spectrum communication system are provided. The constant amplitude decoding apparatus includes: a despreading and demultiplexing module receiving a data stream of a constant amplitude and despreading and demultiplexing the received data stream to restore it to a 2D signal; a decoding module first performing a vertical decoding on the 2D signal and then performing horizontal decoding thereon; a control module determining whether to repeatedly perform vertical decoding and horizontal decoding; and a bit stream information output module outputting the decoding results from the decoding module as a bit stream.

Constant amplitude decoding apparatus and method for multiplexed direct-sequence spread communication system

A medium access control (MAC) technique of a multihop sensor network. In the multihop sensor network, the MAC technique may contribute to significantly reducing transmission delay, and allow real-time services to be provided to all nodes by extending a guaranteed time slot (GTS) restricted to one hop in a personal area network (PAN) coordinator (PNC) to all nodes. Furthermore, the MAC technique may allow the number of available GTSs to be significantly increased, by using all 16 frequency band channels instead of using only a single frequency band and setting a multi-superframe.

Sensor network medium access control (MAC) system for multihop communication

There is provided a mesh routing method in beacon-enabled wireless AD-HOC networks that includes: broadcasting, by nodes constituting a wireless AD-HOC network, a beacon message loading neighbor node information on a beacon payload; managing, by a node receiving the broadcasted beacon message, its own neighbor node table by extracting the neighbor node information loaded on the beacon payload; and performing, by a source node attempting to transmit data or commands, mesh routing on the basis of its own neighbor node table.

Mesh routing method and mesh routing apparatus in beacon enabled wireless AD-HOC networks

There are provided an adaptive collision avoidance apparatus and a method in a channel-hopping based wireless AD-HOC networks. The adaptive collision avoidance apparatus is configured to include a channel quality measuring unit that measures the quality of each channel by using receiving frames; an unavailable channel classifying unit that classifies unavailable channels not to perform communications in the future based on information on the quality of each channel; an unavailable channel propagating unit that transfers a list of unavailable channels classified as unavailable channels to adjacent nodes; and a transceiver that transmits and receives frames through channels not classified as the unavailable channels.

Adaptive collision avoidance apparatus and method in channel-hopping based wireless AD-HOC networks

Disclosed are an apparatus and method for constant amplitude encoding of a transmission signal in a CDM (Code Division Multiplexing) communication system. The apparatus for constant amplitude encoding of a transmission signal includes: an encoding module sequentially performing horizontal encoding and vertical encoding on an input signal; and a spreading and multiplexing module spreading the signal which has been encoded by the encoding module and multiplexing the spread signal in a vertical direction to output a data stream having a constant amplitude.

Constant amplitude encoding apparatus and method for code division multiplexing communication system

A distributed channel hopping communication method in a low power wireless ad-hoc network. A beacon transmission and reception scheduling method using a distributed channel hopping method in a wireless ad-hoc network, the method includes: transmitting beacons using channel hopping, before establishing the wireless ad-hoc network including a plurality of nodes having a BP including at least one time slot, and receiving beacons of a plurality of neighboring nodes of each of the plurality of nodes; collecting information about the wireless ad-hoc network and information about the plurality of neighboring nodes from the received beacons; scheduling the receiving of the beacons that are transmitted from the plurality of neighboring nodes in the BP, using TDMA in each of the at least one time slot based on the information about the plurality of neighboring nodes; and scheduling transmitting of a beacon in each of the at least one time slot.

Distributed channel hopping method in wireless ad-hoc network

Provided is a resource allocation method performed in a wireless network formed of a plurality of nodes, the resource allocation method including the operations of forming clusters and electing cluster heads respectively for the clusters; determining whether a node from among the plurality of nodes forming the wireless network is an edge node; if the node is not the edge node according to a result of the determining, collecting link information related to other nodes in a cluster that comprises the node, and delivering the link information to a cluster head of the cluster; and if the node is the edge node according to a result of the determining, otherwise, obtaining link information and scheduling information from an edge node of another cluster within a communication range with the cluster comprising the edge node, and delivering the link information and scheduling information to the cluster head. The resource allocation method decentralizes a load of calculations to several nodes, wherein the load may be centralized to one node in a large ad-hoc network, so that an energy efficiency of the node may be increased, and since the several nodes sequentially perform simple calculation, a total of the resource allocation time may be reduced.

Resource allocation method in wireless network

A wireless network system using a cyclic frame including a beacon period (BP), a mesh contention access period (MCAP), and a slot period (SP). The cyclic frame has a frame structure that shares a channel hopping sequence of a node, thereby sharing the channel hopping sequence that operates as an existing mesh node without generating an additional channel hopping sequence, and supporting mesh and star type topologies together in order to efficiently operate a network.

Wireless network system using cyclic frame

Provided is a method and apparatus for controlling congestion of a node in an ad-hoc network comprising: classifying a channel state into a busy channel state and an idle channel state and then monitoring the channel state; performing contention for acquiring a channel with neighboring nodes when data to be transmitted is present during the monitoring of the channel state; calculating an available bandwidth on the basis of the channel state when wins the contention; and determining the amount of data to be transmitted on the basis of the available bandwidth. The nodes in the ah-hoc network monitor their own wireless channel state so as to obtain channel contention information, calculate an available bandwidth from the channel contention information, and control a transmission amount on the basis of the available bandwidth. Accordingly, the nodes can avoid excessive traffic which exceeds channel capacity. Channel contention, which is the most immediate and important cause of a decrease in network performance, can be loosened.

Growing community of inventors

Daejeon, South Korea

Seong Soon Joo