• Journal of Korea Multimedia Society
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• v.20 no.8
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• pp.1357-1368
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• 2017

Sensor networks are used in various fields such as marine, defense, and smart home etc. Among the components of the sensor network, the sensor node collects sensor data, as one of the representative sensor network roles, and the sensor node makes a greate influence on the overall performance of the sensor network. Therefore, how to design the sensor node is an important issue in the sensor network field. However, the research on the sensor network architecture suitable for the sensor network installation environment has been made more important than the research on how to configure the sensor node. In this paper, we propose to identify elements to be considered for designing a sensor node that makes a large influence on the performance of the sensor network, and to easily implement the sensor node through the state transition model based on these elements.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.3
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• pp.333-343
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• 2009

Tactical Information Communication Network(TICN) is a concept-type integrated Military Communication system that enables precise command control and decision making by unifying the diversified military communication network and conveying diverse range of battle field information on real-time, at right place at right time. TICN is designed to advance into high speed, large capacity, long distance wireless relay transmission. To support mobility in battlefield environments, the application of Ad-hoc networking technology to its wireless communication has been examined. Ad-hoc network is consist of mobile nodes and nodes in the network depends on the cooperation of other nodes for forwarding of packets. In this context, some non-cooperating nodes may delay forwarding of packets or drop the packets. This may hamper the network as a whole and disrupt communication between the cooperating nodes. To solve this problem, we present a solution with a Node Weight Management Server(NWMS), which manages each node's weight according to its behavior in local area. When the NWMS detects misbehaving node, it increases the node's weight. If the node's weight exceeds a predefined threshold then the NWMS broadcasts the node's information into network to isolate the misbehaving node from the network. These mechanisms show that they are highly effective and can reliably detect a multitude of misbehaving node.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.1529-1532
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• 2004

A Mobile Ad Hoc NETwork (MANET) is a collection of wireless mobile nodes that forms a temporary network without the need for any existing network infrastructure or centralized administration. Therefore, such a network is designed to operate in a highly dynamic environment due to node mobility. In mobile ad hoc network, frequent topological changes cause routing a challenging problem and without the complete view of the network topology, establishing the shortest path from the source node to the destination node is difficult. In this paper, we suggest a routing approach which utilizes location information to setup the shortest possible path between the source node and the destination node. Location information is obtained through Global Positioning System (GPS) and this geographical coordinate information of the destination node is used by the source node and intermediate nodes receiving route request messages to determine the shortest path to the destination from current node.

• Journal of Information Processing Systems
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• v.2 no.1
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• pp.6-12
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• 2006

Peer-to-Peer (P2P) networks are attracting considerable research interest because of their scalability and high performance relative to cost. One of the important services on a P2P network is the streaming service. However, because each node in the P2P network is autonomous, it is difficult to provide a stable streaming service on the network. Therefore, for a stable streaming service on the P2P network, a fault-tolerant scheme must be provided. In this paper, we propose two new node selection schemes, Playback Node First (PNF) and Playback Node first with Prefetching (PNF-P) that can be used for a service migration-based fault-tolerant streaming service. The proposed schemes exploit the fact that the failure probability of a node currently being served is lower than that of a node not being served. Simulation results show that the proposed schemes outperform traditional node selection schemes.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.917-918
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• 2009

This study evaluated the level of performance improvement in the form of a simulated experiment by adding fixed node in the middle of the network as a way to improve mobile ad.hoc network performance. The result showed that the performance level was much higher when fixed node was used together than when mobile node was used only, and the comparison of the mobile speed of mobile node also showed that use of fixed node together had higher performance. Moreover, the evaluation in accordance with the number of fixed node showed that more number of fixed node had shorter time delay. Further study following this on how many fixed node should be added on the ad.hoc network will ensure establishment of more reliable ad.hoc network.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.3
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• pp.1481-1501
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• 2019

In opportunistic network, the behavior of a node is autonomous and has social attributes such as selfishness.If a node wants to forward information to another node, it is bound to be limited by the node's own resources such as cache, power, and energy.Therefore, in the process of communication, some nodes do not help to forward information of other nodes because of their selfish behavior. This will lead to the inability to complete cooperation, greatly reduce the success rate of message transmission, increase network delay, and affect the overall network performance. This article proposes a hybrid incentive mechanism (Mim) based on the Reputation mechanism and the Credit mechanism.The selfishness model, energy model (The energy in the article exists in the form of electricity) and transaction model constitute our Mim mechanism. The Mim classifies the selfishness of nodes and constantly pay attention to changes in node energy, and manage the wealth of both sides of the node by introducing the Central Money Management Center. By calculating the selfishness of the node, the currency trading model is used to differentiate pricing of the node's services. Simulation results show that by using the Mim, the information delivery rate in the network and the fairness of node transactions are improved. At the same time, it also greatly increases the average life of the network.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.3
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• pp.91-98
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• 2013

Node which plays the role of cache server does not exist in the wireless ad-hoc network consisting of only mobile nodes. Even if it exists, it is difficult to provide cache services due to the movement of nodes. Therefore, the cooperative cache technique is necessary in order to improve the efficiency of information access by reducing data access time and use of bandwidth in the wireless ad-hoc network. In this paper, the whole network is divided into zones which don't overlap and master node of each zone is elected. General node of each zone has ZICT and manages cache data to cooperative cache and gateway node use NZCT to manage cache information of neighbor zone. We proposed security structure which can accomplish send and receive in the only node issued id key in the elected master node in order to prepare for cache consistent attack which is vulnerability of distributed caching techniques. The performance of the proposed method in this paper could confirm the excellent performance through comparative experiments of GCC and GC techniques.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.1
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• pp.39-45
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• 2014

This paper proposes an architecture of a sensor network for gathering data under a powerful beam cluster tree architecture. This architecture is used when there is a need to gather data from sensor node where there is no sink node connected to an existing network, or it is required to get a series of data specific to an event or time. The transmit distance of the beam signal is longer than that of the usual sensor node. The nodes of the network make a tree network when receiving a beam message transmitting from the powerful root node. All sensor nodes in a sink tree network synchronize to the superframe and know exactly the sequence value of the current superframe. When there is data to send to the sink node, the sensor node sends data at the corresponding allocated channel. Data sending schemes under the guaranteed time slot are tested and the delay and jitter performance is explained.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.4
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• pp.95-101
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• 2013

MANET has an advantage that can build a network quickly and easily in difficult environment to build network. In particular, routing protocol that uses in existing mobile environment cannot be applied literally because it consists of only mobile node. Thus, routing protocol considering this characteristic is necessary. Malicious nodes do extensive damage to the whole network because each mobile node has to act as a router. In this paper, we propose technique that can detect accurately the suspected node which causes severely damage to the performance of the network. The proposed technique divides the whole network to zone of constant size and is performed simultaneously detection technique based zone and detection technique by collaboration between nodes. Detection based zone translates the information when member node finishes packet reception or transmission to master node managing zone and detects using this. The collaborative detection technique uses the information of zone table managing in master node which manages each zone. The proposed technique can reduce errors by performing detection which is a reflection of whole traffic of network.

• Journal of the Korea Society of Computer and Information
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• v.11 no.1 s.39
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• pp.195-201
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• 2006

This thesis proposes hybrid routing protocol that mix proactive routing protocol and reactive routing protocol used in Ad hoc network. Proposed method is that establish special node offering network service of nods which construct Ad hoc network and do routing different from existing hybrid routing protocol, ZRP. Special node doing these parts is called C-node. Routing using C-node can accompany efficient routing by decreasing path institution time and flooding time than existing routing protocol.