Abstract: A network broadcast method using a MAC unicast and an MPR node allows a source node to transmit a data packet to at least one MPR node which is located within one-hop distance from the source node and allows the at least one MPR node to transmit the data packet to each next-ranked MPR nodes. At least one normal node, which is not an MPR node while being located within one-hop distance from the source node, receives the data packet of the source node, which is transferred from the source node to an MPR node or transferred between MPR nodes through overhearing. Although the source node and MPR nodes are in a hidden-node relationship, collision is prevented, thereby minimizing data packet loss to improve the transmission reliability, and enabling the data packet of the source node to be reliably broadcasted on a network.

Abstract: A gateway for interconnection of heterogeneous middleware includes a high level architecture (HLA) federate; a data distribution service (DDS) participant; a clock federate for a wall clock; and a time manger configured to synchronize times of the HLA federate and the DDS participant to the wall clock provided by the clock federate.

Abstract: Disclosed are a computing apparatus for providing an entity search means so as to perform data communication between different entities of a Data Distribution Service (DDS) in a multi-network domain environment, and a method of operating the same. A method of operating a computing system for a Data Distribution Service (DDS) service in a DDS system including a first network domain and a second network domain includes: searching for search information of DDS entities included in the first network domain; determining at least a DDS entity among the DDS entities as a representative entity of the first network domain; and providing the search information of the DDS entities to a representative entity of the second network domain through the representative entity of the first network domain.

Abstract: Disclosed herein is a method of selecting a relay node in a mobile ad-hoc network. The relay node selection method includes updating a neighbor node list based on messages received from one or more other nodes, and selecting a 1-hop neighbor node having a highest Multi-Point Relay (MPR) selector counter (MSC) value, from among one or more 1-hop neighbor nodes included in the updated neighbor node list, as an MPR node. Therefore, the present invention can prevent unnecessary channel competition and conflicts between nodes and improve network performance.

Abstract: A multicast routing apparatus in a wireless mesh network and a method thereof are disclosed. The multicast routing apparatus in the wireless mesh network includes: an information obtaining unit configured to obtain group identification (ID) information of neighboring mesh stations corresponding to the respective mesh stations; a selecting unit configured to select a multicast forwarding candidate corresponding to a candidate of the mesh stations capable of participating in forwarding multicast data packet using the group ID information; a tree generating unit configured to generate a tree corresponding to a transmission path of the multicast data packet; and a packet transmitting unit configured to transmit data packet from a transmitting mesh station to a receiving mesh station of the mesh stations using the tree.

Abstract: A network broadcast method using a MAC unicast and an MPR node allows a source node to transmit a data packet to at least one MPR node which is located within one-hop distance from the source node and allows the at least one MPR node to transmit the data packet to each next-ranked MPR nodes. At least one normal node, which is not an MPR node while being located within one-hop distance from the source node, receives the data packet of the source node, which is transferred from the source node to an MPR node or transferred between MPR nodes through overhearing. Although the source node and MPR nodes are in a hidden-node relationship, collision is prevented, thereby minimizing data packet loss to improve the transmission reliability, and enabling the data packet of the source node to be reliably broadcasted on a network.

Abstract: The present invention relates to an apparatus and method for providing and controlling multimedia group communication service based on a mesh network. The apparatus for providing a group communication service includes a group communication management module, and an audio and video management module. The group communication management module controls and manages group communication between a plurality of user terminals connected to an internal network independent of an external network. The audio and video management module receives audio and video data for group communication from the microphone and camera of each of the user terminals and manages the audio and video data. The group communication management module includes a packet management unit configured to generate packets that are used to control the group communication, a terminal search unit, and a group communication control unit.

Abstract: Disclosed herein is a method of selecting a relay node in a mobile ad-hoc network. The relay node selection method includes updating a neighbor node list based on messages received from one or more other nodes, and selecting a 1-hop neighbor node having a highest Multi-Point Relay (MPR) selector counter (MSC) value, from among one or more 1-hop neighbor nodes included in the updated neighbor node list, as an MPR node. Therefore, the present invention can prevent unnecessary channel competition and conflicts between nodes and improve network performance.

Abstract: A collision avoidance method and an apparatus thereof in a wireless network are provided. The collision avoidance method in the wireless network includes receiving first data from a source node, determining whether a history in which data has been previously received from the source node is present, and determining a data transmission period of the source node based on the history when the history is present, and the data transmission period is calculated when data is received from the source node. Accordingly, a collision probability can be reduced in an environment in which wireless data is periodically transmitted in a CSMA/CA manner.