Abstract: According to an exemplary embodiment of the present invention, a method for time synchronization of a first node in a peer aware communication (PAC) environment is provided. The first node obtains medium access control authority by performing contention with a second node neighboring the first node. The first node adds a time synchronization offset to the first beacon frame. In addition, the first node transmits the first beacon frame in a beacon period of a superframe when obtaining the media access control authority.

Abstract: A received signal strength indicator is provided. The received signal strength indicator includes a plurality of differential amplifiers forming an amplifier chain for amplifying differential signals and a plurality of rectifiers for rectifying signals output from the plurality of differential amplifiers and the differential signals, and a low pass filter for combining the signals rectified by the plurality of rectifiers to output received signal strength. Each rectifier includes a class AB voltage-current converter for converting a differential voltage into a current, and two triode transistors.

Abstract: A wireless communication method using a control channel between wireless communication devices including: exchanging profile information between a node and intermediate relay nodes therearound so as to allow the node to transmit/receive data to/from a destination node; determining, by the node, a first intermediate relay node using the profile information and determining a wireless communication mode with the first intermediate relay node; and transmitting/receiving data between the node and the first intermediate relay node by the determined wireless communication mode is provided.

Abstract: A method of operating a device capable of periodically hopping a predetermined interval using a channel hopping sequence in order to improve low radio frequency (RF) reliability caused by single frequency based channel access.

Abstract: A method and apparatus for encoding a constant amplitude that is applied to a code division multiplexing communication system are provided. By dividing a data bit into a block unit, the receiving side can easily determine an error, and by reducing power consumption in outdoor wide area communication using a bit string of a small length in a basic unit of an input frame, efficiency can be improved, and thus a physical layer of a ubiquitous sensor network can be optimized.

Abstract: A method and apparatus for allocating a management resource of a channel of a node that is included in a wireless personal area network (WPAN) are provided. A resource of a channel performs communication with a specific node using a multi-superframe including a plurality of superframes, limits a position area of a time slot including a channel that is allocated to communication with a specific node to a predetermined superframe of the plurality of superframes, gives a logical connection ID to the time slot, and is allocated by matching the logical connection ID and a management resource that manages the time slot.

Abstract: An end device transmits a request command for requesting a slot management to a coordinator, and receives a reply command including a result of the slot management request from the coordinator. Each of the request command and the reply command includes an allocation order for indicating a slot allocation interval request.

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: A hybrid virtual multiple-input multiple-output (V-MIMO) transmission method of a management node in a wireless ad-hoc network in which a transmission path from a source node to a destination node is divided into one or more sections is provided. The hybrid V-MIMO transmission method includes obtaining one or more pieces of node information of one or more nodes by transmitting an information request message to the nodes in response to a transmission request message for data transmission from the source node to the destination node; setting a shortest path (SP) from the source node to the destination node based on the obtained node information; determining transmission schemes individually for nodes present on the SP; issuing a transmission preparation request by transmitting the determined transmission schemes to the respective corresponding nodes; and transmitting a transmission start message to the source node in response to transmission ready responses from the respective nodes.

Abstract: 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.

Abstract: 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.

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 quickly adapts to changes and reduces power consumption.

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: 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: 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.

Abstract: Provided is a method of performing a routing and allocating a resource in a wireless sensor network. The method includes electing one or more cluster heads, each representing each of one or more clusters comprised of a plurality of sensor nodes, selecting a routing path between the cluster heads and the plurality of sensor nodes, selecting a frame length based on elements and distribution methods of the wireless sensor network and the routing path, forming a time slot resource allocation table for communication between the cluster heads, and exchanging the time slot resource allocation table between the cluster heads separated by one hop. The present invention can enhance the reliability of the wireless sensor network and QoS by effectively performing routing and allocating resources in such a manner that various data requirements can be satisfied.

Abstract: In a wireless sensor network system including at least one sensor network, when a network message received from a sensor node of a sensor network corresponds to a predetermined service, the wireless sensor network system forms a wireless local area network (WLAN) overlay network which is based on a WLAN system within a service area at which the sensor node is located. Data corresponding to the predetermined service is transmitted and received through the WLAN overlay network.

Abstract: A complex communication apparatus transmits/receives voice information with other complex communication apparatuses through a set voice channel. The complex communication apparatus broadcasts a signaling packet expressing a destination identifier representing a desired communication type of one-to-one communication, group communication, and broadcast communication with other complex communication apparatuses and information of the set voice channel and performs voice communication with a complex communication apparatus corresponding to a destination identifier of other complex communication apparatuses, having received the signaling packet.

Abstract: A slot managing method and apparatus is provided. A first layer of a destination node receives a request command for requesting a slot management from a source node, and transfers a first primitive for reporting a receipt of the request command to a second layer that is an upper layer of the first layer. The second layer transfers a second primitive to the first layer as a response to the slot management request. The first layer broadcasts a reply command including a result of the slot management request to neighboring nodes in response to the second primitive. The source node broadcasts a notify command including a result of the slot management request.

Abstract: A method of operating a device capable of periodically hopping a predetermined interval using a channel hopping sequence in order to improve low radio frequency (RF) reliability caused by single frequency based channel access.