Abstract: Provided is a method for forming a customized-quality integrated transport network based on synch and asynch frames, and a transport network forming apparatus thereof. The method of the present invention includes: a) synchronizing a transmission bit rate in a network; b) when the transmission bit rate is synchronized in the network and a connection request is received, establishing a connection by determining a route and a start cycle time of the link based on a quality of the connection request and transporting it to nodes of the link; and c) transmitting data to be transported to a link of an adjacent node within the virtual cycle time when the data are synch frames; or when the data are asynch frames and the data are not transmitted within a virtual cycle time of a link to be switched, keeping the data waiting for a next cycle time.

Abstract: 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.

Abstract: There is provided an asynchronous multi-channel adaptation method. An asynchronous multi-channel adaptation method according to an aspect of the invention may include: a channel scanning operation in which a new node, participating in a wireless ad-hoc network, scans channels and selects a receiving channel thereof; and a receiving channel information transmission operation in which the new node transmits information on the selected receiving channel thereof to a neighboring node.

Abstract: There is provided a data communication method using a body area network superframe including an advertisement period, a contention medium access period, a beacon period, and a data transmit period, the data communication method including: broadcasting, by a coordinator node, predetermined information during the advertisement period; transmitting, by nodes, which wish to transmit data, the data only when carrier is not in use as a result of sensing the carrier after the contention medium access period is initiated and a predetermined backoff time elapses; broadcasting, by each of the nodes, periodic beacon signals during the beacon period; and transmitting, by each of the nodes, continuous data and periodic data during the data transmit period

Abstract: The present research relates to s a transmission frame structure supporting a data service and a circuit service of diverse bands in a Synchronous Optical Network (SONET)/Synchronous Digital Hierarchy (SDH) network. This research provides a transmission frame structure including a sync period, an async period, and a control period and provides a multiplexing apparatus that can add or extract a fixed length frame in the synch period of the transmission frame and add or extract a variable length frame in the asynch period, and a method for transmitting the transmission frame. The transmission frame structure includes a sync period for transmitting a fixed length frame; an async period for transmitting a variable length frame; and a control period for transmitting a control frame storing information for discriminating between the sync period and the async period. The technology of this research can be applied to a synchronous optical network system.

Abstract: A decentralized scheduling method in a wireless ad hoc network is provided which includes grouping nodes in the network cluster by cluster, determining a cluster head of each cluster, and sequentially performing scheduling cluster by cluster. Accordingly, it is possible to provide an efficient cluster-based scheduling method which is quickly adapt to changes and reduces power consumption.

Abstract: Provided is a method of determining an operation mode of a node in an ad hoc network. The method includes: monitoring a measured amount of residual energy of the node and comparing the measured amount of residual energy of the node with an amount of residual energy theoretically calculated for the node; identifying an amount of information in a queue included in the node; calculating a relay probability of the node by reflecting the identified amount of information in the queue and the result of comparing the measured amount of residual energy of the node with the theoretically calculated amount of residual energy for the node; and determining the operation mode of the node to be one of a relay mode and a transmission mode, based on the calculated relay probability of the node. The method enables nodes to exchange information about their respective amounts of residual energy and analyze the information without using additional resources and processes.

Abstract: Disclosed are a sensor node having a self localization function and a self localization method of the sensor node. The sensor node calculates a location thereof by receiving location information measured at each of two mobile nodes at different times and using four location information of the received location information. Additional cost and power consumption required for installing additional equipment such as an anchor node, a ultrasonic transceiver and a signal amplifier are reduced.

Abstract: Provided are a sensor node included in a sensor network, an update server updating the sensor node, and a method of updating a sensor node. The update server updating a sensor node included in a sensor network includes an execution code manager managing execution codes for a plurality of sensor nodes included in the sensor network, a rule generator generating an update rule based on a result of comparing an existing execution code managed by the execution code manager with an update execution code required for a new function update of the sensor node, and a downloader causing the sensor node to download the update rule generated by the rule generator. Accordingly, an execution code can be updated by a small amount of data transmission.

Abstract: An apparatus and method for establishing a routing path in a ZigBee network including a device in sleep mode is provided. The method includes receiving a route request command, and establishing a path with reference to sleep information of a destination device and of all devices located on a path to the destination device. Accordingly, while the devices are allowed to sleep for energy efficiency even in a non-beacon-enabled mode, an ad-hoc on-demand distance vector (AODV)-based mesh routing method which uses a route request command (RREQ) and a route reply command (RREP) can be used as is, and thus the ZigBee network can be utilized in more various application fields.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Provided is a method of synchronizing time for a multihop sensor network. According to the method, receiving nodes accurately synchronize time by adding a delay transmission time value to a beacon frame in a beacon mode, or by using a time synchronization frame and time synchronization acknowledgement frame containing time information and superframe structure information in a non-beacon mode. Accordingly, a mesh topology is supported, and a media access control (MAC) structure having high reliability and low delay time is provided.

Abstract: A method for transferring data frame end-to-end in a local area network is provided. In the method, a virtual synch frame shaper is loaded on a frame transmission layer structure provided in end stations in transmitting and receiving sides, which transmits data frame passing through a plurality of Ethernet switches in the LAN. Then, slot counters, which are counted through the virtual synch frame shaper, are exchanged between the end stations, and the slot counters are synchronized. Afterward, the transmit time slot is allocated based on the synchronized slot counters for transmitting data frames between the end stations. Finally, data frames are transmitted based on the synchronized slot counters and the allocated transmit time slot.

Abstract: Provided is a method for forming a customized-quality integrated transport network based on synch and asynch frames, and a transport network forming apparatus thereof. The method of the present invention includes: a) synchronizing a transmission bit rate in a network; b) when the transmission bit rate is synchronized in the network and a connection request is received, establishing a connection by determining a route and a start cycle time of the link based on a quality of the connection request and transporting it to nodes of the link; and c) transmitting data to be transported to a link of an adjacent node within the virtual cycle time when the data are synch frames; or when the data are asynch frames and the data are not transmitted within a virtual cycle time of a link to be switched, keeping the data waiting for a next cycle time.

Abstract: The present research relates to s a transmission frame structure supporting a data service and a circuit service of diverse bands in a Synchronous Optical Network (SONET)/Synchronous Digital Hierarchy (SDH) network. This research provides a transmission frame structure including a sync period, an async period, and a control period and provides a multiplexing apparatus that can add or extract a fixed length frame in the synch period of the transmission frame and add or extract a variable length frame in the async period, and a method for transmitting the transmission frame. The transmission frame structure includes a sync period for transmitting a fixed length frame; an async period for transmitting a variable length frame; and a control period for transmitting a control frame storing information for discriminating between the sync period and the async period. The technology of this research can be applied to a synchronous optical network system.

Abstract: 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.

Abstract: A multi-dimensional optical cross-connect switching system. The system is capable of multi-dimensionally using wavelength resources, such as in the forms of optical fibers, optical wavelength bands and optical wavelengths. The system can three-dimensionally use the wavelength resources by being matched with an optical transport network through the optical fiber layer, optical wavelength band layer and optical wavelength layer. In addition, the multi-dimentional optical cross-connect switching system is constructed in such a way that two cross-connect switches are symmetrically arranged and an insertion/extraction switch is added to switch addition/dropping links between the two switches.