• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3176-3182
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• 2009

The PBNM on MANET is being researched to ensure the reliability and efficiency between mobile nodes. Therefore, it is essential to determine the cluster effectively which will perceive the movements of nodes and distribute the policies. In PBNM mechanism, to determine the node cluster for PDP and manage PEP nodes, Active PDP Discovery Protocol is proposed as a mechanism which is more efficient than preexistent techniques. While k-hop cluster selects the PEP nodes which PDP node manages, Active PDP Discovery actively selects the PDP node among the moving PEP node. This method prevents orphan nodes that are not connected to PDP and reduces continual broadcasting messages. This paper implements Active PDP Discovery which determines cluster in the real networks and analyzes its capability, expanding COPS-PR to detect the movement of nodes and adding MNL to PDP node.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.4
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• pp.781-787
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• 2007

Network Mobility (NEMO) basic support protocol doesn't execute the process of route optimization and has not presented the particular security mechanism in other blocks except hi-directional tunnel between Mobile Router (MR) and its Home Agent (HA). Therefore in this paper we process secure route optimization courses through authenticated binding update protocol between MR and its Correspondent Node (CN) and the protocol of the competency of mandate between MR and its Mobile Network Node (MNN); its block also uses an bi-directional tunnel as the block between MR and its HA. The address of each node are generated by the way of Cryptographically Generated Address (CGA) for proving the ownership of address. Finally we analyze the robustness of proposed protocol using security requirements of MIPv6 and existing attacks and the efficiency of this protocol using the connectivity recovery and end-to-end packet transmission delay time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6329-6335
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• 2014

In the Strut-Tie-Model(STM), the width of a node is important in both analysis and design. Its effects on the force distribution at truss analogy system. In addition, it effects the verification of all struts and nodes, which need to be checked to satisfy the code of design. Code here refers to the ACI-318 code. Four methods were used to define the width of node: 1) effective depth is assumed to equal to 0.9 of the overall depth of beam, 2) moment equilibrium 3) assumption of the width of node at the bottom equal to 380mm, and 4) the new proposed method by this study. 106 selected samples of a parametric study obtained from the four methods were analyzed. Because total steel requirement from these four methods are similar, the easiest would be a good choice for a time saving calculation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.11
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• pp.1909-1928
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• 2011

Node cooperation during packet forwarding operations is critically important for fair resource utilization in Community Wireless Mesh Networks (CoWMNs). In a CoWMN, node cooperation is achieved by using fairness protocols specifically designed to detect and isolate malicious nodes, discourage unfair behavior, and encourage node participation in forwarding packets. In general, these protocols can be split into two groups: Incentive-based ones, which are managed centrally, and use credit allocation schemes. In contrast, reputation-based protocols that are decentralized, and rely on information exchange among neighboring nodes. Centrally managed protocols inevitably suffer from scalability problems. The decentralized, reputation-based protocols lacks in detection capability, suffer from false detections and error propagation compared to the centralized, incentive-based protocols. In this study, we present a new fairness protocol management scheme, called Hybrid FPMS that captures the superior detection capability of incentive-based fairness protocols without the scalability problems inherently expected from a centralized management scheme as a network's size and density grows. Simulation results show that Hybrid FPMS is more efficient than the current centralized approach and significantly reduces the network delays and overhead.

• ETRI Journal
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• v.36 no.1
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• pp.1-11
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• 2014

In this paper, we propose a distributed synchronization algorithm for wireless mesh networks based on orthogonal frequency division multiple access. For time and frequency synchronization, a node requests its neighbor nodes for a change of fast Fourier transform starting points, transmission times, and carrier frequencies needed for synchronization. The node also updates its own time and frequency elements through simple formulas based on request messages received from neighbor nodes using a guard interval and a cyclic prefix. This process with the cooperation of neighbor nodes leads to a gradual synchronization of all nodes in the network. Through a performance comparison with a conventional scheme, we obtain simulation results indicating that the proposed scheme outperforms the conventional scheme in random topologies and a grid topology.

• ETRI Journal
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• v.36 no.1
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• pp.183-186
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• 2014

In this letter, we consider a cooperation system with multiple untrusted relays (URs). To keep the transmitted information confidential, we obtain joint channel characteristics (JCCs) through combining the channels from the source to the destination. Then, in the null space of the JCCs, jammers construct artificial noise to confuse URs when the source node broadcasts its data. Through a distributed implementation algorithm, the weight of each node can be obtained from its own channel state information. Simulation results show that high-level security of the system can be achieved when internal and external eavesdroppers coexist.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.306-310
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• 2012

Location tracking system represents position by searching objects and humans. In this paper I would like to write about RF chip support Zigbee which is called CC2420. In simulated network circumstance, we can get the information about mobile-node by sending it to sink-node. Position finding is in error by 3m at outdoor environment. The error scale is acceptable within easy range of naked eyes. It can be overcome by using GPS information and Google maps with the wireless networking background.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.1C
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• pp.99-106
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• 2005

This Paper suggests the cooperation scenarios between Diameter protocol and Mobile IPv6 protocol. First, this paper designs cooperation scenarios and designs mobility support technology based on the designed scenarios. This paper deanes the interfaces between mobile node and local AAA client using ICMPv6 messages. In addition, this paper designs handoff procedures according to the area, which mobile node moves to.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1647-1652
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• 2008

The PEGASIS protocol is more effective about energy consumption more than LEACH in USN environment. However, PEGASIS is weakness enemy in change of sensor network net composition because It changes BS node frequently. Therefore, we propose new routing protocol that use Sub-Cluster Chaining to solve this problem in this paper. It can reduce overhead that happen in election of middle node doing so and reduce energy consumption. Also, It can supplement limitation that PEGASIS has. This is treatise shows that new protocol that propose than existent PEGASIS through simulation is superior.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.1-10
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• 2021

The interest in underwater acoustic sensor networks (UWASNs), along with the rapid development of underwater industries, has increased. To operate UWASNs efficiently, it is important to adopt well-designed medium access control (MAC) protocols that prevent collisions and allow the sharing of resources between nodes efficiently. On the other hand, underwater channels suffer from a narrow bandwidth, long propagation delay, and low data rate, so existing terrestrial node pairing schemes for non orthogonal multiple access (NOMA) cannot be applied directly to underwater environments. Therefore, a multi-dimensional node pairing scheme is proposed to consider the unique underwater channel in UWASNs. Conventional NOMA schemes have considered the channel quality only in node pairing. Unlike previous schemes, the proposed scheme considers the channel gain and many other features, such as node fairness, traffic load, and the age of data packets to find the best node-pair. In addition, the sender employs a list of candidates for node-pairs rather than path loss to reduce the computational complexity. The simulation results showed that the proposed scheme outperforms the conventional scheme by considering the fairness factor with 23.8% increases in throughput, 28% decreases in latency, and 5.7% improvements in fairness at best.