Abstract: A method and system for performing re-association in a WLAN mesh network are provided. A mobile node transmits authentication request information to an old node via a new node along with a mesh re-association request message for re-association of the mesh network. Upon receiving the mesh re-association request message, the old node performs re-association and authentication according to the mesh re-association request message, and transmits a mesh re-association reply message to the mobile node via the new node.

Abstract: A method and system for performing re-association in a WLAN mesh network are provided. A mobile node transmits authentication request information to an old node via a new node along with a mesh re-association request message for re-association of the mesh network. Upon receiving the mesh re-association request message, the old node performs re-association and authentication according to the mesh re-association request message, and transmits a mesh re-association reply message to the mobile node via the new node.

Abstract: A channel scanning method and system at an MP within a mesh network associated with a local network are provided. A MAP sends a local management frame including information about a mesh network on an allocated local channel and sends a mesh management frame on a mesh channel indicated by the mesh network information. An MP scans a plurality of channels including the local channel and the mesh channel in an order of channels numbers, receives the local management frame by scanning the local channel, and receives the mesh management frame by scanning the mesh channel based on the mesh network information of the local management frame.

Abstract: Provided is a constellation rotation relay system and constellation rotation relay method which can acquire full diversity gain by performing constellation rotation for a channel matrix in a relay network when configuring a virtual MIMO channel. The constellation rotation system includes a matrix creator for creating a symbol matrix by configuring a symbol transmitted in parallel from a source of a relay network; and a constellation rotation unit constellation rotating the symbol in the symbol matrix by adding a constellation rotation matrix to the created symbol matrix.

Abstract: A method and system of relaying data are provided. The data is encoded into a turbo codeword by using a convolutional turbo code encoder, and the turbo codeword is transmitted from a source to a relay and a destination after puncturing by a first puncturing operation. The first punctured turbo codeword which is received in the relay is de-punctured and regenerated in a decoding operation and the regenerated turbo codeword is transmitted from the relay to the destination in punctured form after puncturing by a second puncturing operation. The punctured turbo codewords received from the source and the relay by the destination are totaled together as a totaled single turbo codeword and the totaled single turbo codeword is completely decoded to recover the data.

Abstract: A method and apparatus for controlling power of a transmitter in a mesh network. A controller, if it sets a reference power to one of a first measured transmission power and a maximum power, compares the reference power with a first power in level, and compares the first power with a second power in level. A cumulation factor calculator calculates a cumulation factor by comparing the first power with the second power. A reference power setter sets the reference power according to a scope to which a value obtained by adding a reference power to a sum of the calculated cumulation factors belongs. A power controller controls transmission power according to the set reference power.

Abstract: In general, an Internet gateway assigns an address to a node of an ad-hoc network on receipt of request for an address assignment. However, a load exerted to the Internet gateway increases. Accordingly, one (proxy node) of the nodes of an ad-hoc network can serve as a proxy node to perform an address assignment function of the Internet gateway. That is, if a node of the ad-hoc node does not receive an advertisement message, it requests the Internet gateway for address assignment to perform the proxy node function. The node is assigned with at least two addresses from the Internet gateway, and then assigns the address to the requesting node. Accordingly, a load exerted to the Internet gateway can be reduced.

Abstract: A power saving method and apparatus are provided for saving power by reducing the number of changes between active mode and sleep mode using multiple channels. A process for negotiating which of multiple channels will be assigned a transmission opportunity (TXOP) is performed. A TXOP MAP is configured by exchanging a packet through a common channel during a predetermined time at every monitoring time according to a negotiated channel. The TXOP is allocated to each channel according to the TXOP MAP. As a change between the active mode and the sleep mode is reduced, power can be saved, resources of the mesh network can be efficiently used, and interference between nodes can be reduced.

Abstract: Embodiments of the present invention provide a method for tracking link mobility between two mobile nodes. Each node estimates a link mobility state of a link between itself and each of its neighbor nodes, accumulates successively the link mobility states, estimates link mobility parameters using the successively estimated link mobility states, and predicts a link availability probability using the link mobility parameters. The link mobility tracking can be applied to various routing protocols so as to implement mobility aware routing which enhance the routing performance.

Abstract: An ad-hoc network and routing method that takes account of mobility are provided. The ad-hoc network includes at least one node, which calculates a probability that a neighbor node is present in a transmission range of the node, generates a message containing the calculated probability, and transmits the message to the neighbor node. The at least one node may also update the message with a lower probability of the calculated probability and a probability contained in the message, and transmit the updated message to the neighbor node. The node may also determine as a route a path along which a message is transmitted from the message containing the highest probability among probabilities contained in messages that are received.

Abstract: A communication method for a mobile communication system having a node for sending data to a gateway via neighboring nodes and gateways for sending the data from the nodes to an Internet network, and for setting a path for data transmissions between a gateway and a node, including: transmitting via the gateway a message including path information and a prefix; and setting a path for sending data to the node that sent the message, when a node that received the message, directly or via another node, has the data to be sent to the gateway; and sending the data via the set path.

Abstract: Provided is a constellation rotation relay system and constellation rotation relay method which can acquire full diversity gain by performing constellation rotation for a channel matrix in a relay network when configuring a virtual MIMO channel. The constellation rotation system includes a matrix creator for creating a symbol matrix by configuring a symbol transmitted in parallel from a source of a relay network; and a constellation rotation unit constellation rotating the symbol in the symbol matrix by adding a constellation rotation matrix to the created symbol matrix.

Abstract: Provided are a network-coding apparatus and method which can increase a data communication capacity in a communication environment to which an error-correction code (ECC) is applied. The network-coding apparatus includes a received signal processing unit receiving at least two signals, and decoding the at least two received signals; and a transmission signal processing unit receiving the at least two decoded signals from the received signal processing unit, merging the at least two decoded signals, and generating a merged transmission signal.

Abstract: Provided is a constellation rotation relay system and constellation rotation relay method which can acquire full diversity gain by performing constellation rotation for a channel matrix in a relay network when configuring a virtual MIMO channel. The constellation rotation system includes a matrix creator for creating a symbol matrix by configuring a symbol transmitted in parallel from a source of a relay network; and a constellation rotation unit constellation rotating the symbol in the symbol matrix by adding a constellation rotation matrix to the created symbol matrix.

Abstract: A method and system for establishing multiple channels between nodes each having a single radio interface in a mesh network supporting multiple channels are provided. Each node in the mesh network initially generates a neighbor node table, taking into account at least one traffic channel temporarily established for data transmission to a neighbor node. The neighbor node table is updated when a traffic channel is established for data transmission to the neighbor node, and the neighbor node table is updated according to channel use information of the neighbor node received from the neighbor node or channel use information of a node two hops away.

Abstract: Provided is a fine frequency synchronization method of a WiBro system, and particularly, a fine frequency synchronization method which measures a spread degree of a received signal of an adjacent subcarrier using orthogonality of PN sequences and thereby estimates a frequency offset, in a base station or a wireless repeater without using a GPS receiver. The fine frequency synchronization method includes: (a) performing despreading on received adjacent subcarrier sequences, using a PN sequence transmitted from a transmitting party; (b) obtaining ratios of correlative values obtained by the despreading; and (c) estimating a frequency offset on the basis of the ratio of correlative values. Accordingly, fine frequency offset estimation with relatively low complexity is possible without using a GPS receiver in a WiBro environment where interference signals of other base stations or repeaters exist.

Abstract: A service provider discovery method in a wireless network environment, includes receiving, by the gateway, a service request (SREQ) packet which is broadcast from a first mobile node in the ad-hoc network; updating and transmitting, by the gateway, the SREQ packet to a service repository which stores at least one service provider information, in the infrastructure network; transmitting, by the service repository, a service reply (SREP) packet containing information relating to a service provider which provides a service requested by the SREQ packet to the gateway, and updating and transmitting, by the gateway, the SREP packet to the first mobile node. Accordingly, the service can be used in association with the ad-hoc network and the infrastructure network.

Abstract: A multi-channel Media Access Control (MAC) method and apparatus for a Wireless Local Area Network (WLAN) device with a single radio interface are provided. The multi-channel MAC method includes sensing a common channel when a channel coordination window starts from a start point of a window repeating at regular periods, allocating at least two devices to a destination channel for the started channel coordination window using a channel utilization vector indicating use/nonuse for each of multiple channels, and transceiving a frame over the allocated destination channel.

Abstract: An apparatus, method and system are provided for routing a broadcast data frame in a mesh network with multiple mesh portals. In the mesh network, every mesh point selects and registers its default mesh portal. A mesh portal enters its address in a destination address field of a broadcast data frame received from outside of the mesh network and broadcasts the data frame to inside of the mesh network. The mesh point processes a received broadcast data frame relating to its registered mesh portal, thereby preventing the broadcast data frame from being redundantly transmitted in the mesh network.

Abstract: An ad-hoc network for routing extension by supporting the IPv6 protocol and a method for routing extension. The ad-hoc network comprises a gateway for appending an address configuration message to an ad-hoc Routing REPly (RREP) message and transmitting an extended ad-hoc RREP message; and a node for separating the address configuration message from the received extended ad-hoc RREP message, establishing a packet transmission path using the ad-hoc RREP message, and configuring a global address using the separated address configuration message. Accordingly, the present invention provides efficiency and improves the network scalability by utilizing the existing IPv6 protocol without amendments and reducing the size of the packet transmitted.