• Journal of the Korea Society of Computer and Information
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• v.17 no.11
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• pp.73-81
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• 2012

This paper proposes an ETWAD(Encapsulation and Tunneling Wormhole Attack Detection) design based on positional information and hop count on Ad-Hoc Network. The ETWAD technique is designed for generating GAK(Group Authentication Key) to ascertain the node ID and group key within Ad-hoc Network and authenticating a member of Ad-hoc Network by appending it to RREQ and RREP. In addition, A GeoWAD algorithm detecting Encapsulation and Tunneling Wormhole Attack by using a hop count about the number of Hops within RREP message and a critical value about the distance between a source node S and a destination node D is also presented in ETWAD technique. Therefore, as this paper is estimated as the average probability of Wormhole Attack detection 91%and average FPR 4.4%, it improves the reliability and probability of Wormhole Attack Detection.

• Journal of Communications and Networks
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• v.17 no.4
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• pp.370-383
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• 2015

Effective link quality estimation is a vital issue for reliable routing in wireless networks. This paper studies the performance of expected transmission count (ETX) under different traffic loads. Although ETX shows good performance under light load, its performance gets significantly worse when the traffic load is high. A broadcast packet storm due to new route discoveries severely affects the link ETX values under high traffic load, which makes it difficult to find a good path. This paper presents the design and implementation of a variation of ETX called high load - ETX (HETX), which reduces the impact of route request broadcast packets to link metric values under high load. We also propose a reliable routing protocol using link quality metrics, which is called link quality distance vector (LQDV). We conducted the evaluation of the performance of three metrics - HETX, ETX and minimum hop-count. The simulation results show that HETX improves the average route throughput by up to 25% over ETX under high traffic load. Minimum hop-count has poor performance compared with both HETX and ETX at all of the different traffic loads. Under light load, HETX and ETX show the same performance.

• Convergence Security Journal
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• v.8 no.1
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• pp.19-26
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• 2008

In wireless sensor networks, an adversary can launch the wormhole attacks, where a malicious node captures packets at one location and tunnels them to a colluding node, which retransmits them locally. The wormhole attacks are very dangerous against routing protocols since she might launch these attacks during neighbor discovery phase. A strategic placement of a wormhole can result in a significant breakdown in communication across the network. This paper presents a compromise-resilient tunneled packet filtering method for sensor networks. The proposed method can detect a tunneled message with hop count alteration by a comparison between the hop count of the message and one of the encrypted hop counts attached in the message. Since the proposed method limits the amount of security information assigned to each node, the impact of wormhole attacks using compromised nodes can be reduced.

• Korean Management Science Review
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• v.12 no.2
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• pp.89-103
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• 1995

Traditionally, the scarce and expensive resources in communication networks has been the bandwidth of transmission facilities; accordingly, the techniques used for networking and switching have been chosen so as to optimize the efficient use of that resource. One of them is the packet switching for data communications, which is much different from the circuit switching. It allows multiple users to share the data network facilities and bandwidth, rather than providing specific amounts of dedicated bandwidth to each users. One main challenge therefore has been to design and build cost-effective packet switching networks. In this paper, we develop a mathematical programming medel and heuristic algorithm for designing the packet switching networks with hop-count constraints. To develop an efficient heuristic, we apply the Lagrangian relaxation method. Some valid inequalities, which have been known as the tight constraints, are considered to improve the bound for Lagrangian sub-problem. The computational experiments show that the performance of the proposed heuristic is very satisfactory in both the speed and the quality of design solutions generated.

• Journal of Computing Science and Engineering
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• v.5 no.1
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• pp.19-31
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• 2011

In this paper, we propose two new routing schemes for double-layered peer-to-peer systems; a shorter-lower mobility routing scheme and a reverse path routing scheme. The shorter-lower mobility routing scheme first chooses shortest routing paths among possible routing paths and selects the path associated with the relay peer who has lower mobility to improve the reliability of the system. The reverse path routing scheme carries out unicasting (instead of multicasting) based on the reverse path information that can be obtained during the initial file search to further reduce network traffic. The experimental results showed that a double-layered peer-topeer system with the proposed hybrid scheme improved the reliability of the system about 1.5% over the hop count scheme and reduced network traffic by about 0.5% compared to the hop count scheme.

• The KIPS Transactions:PartC
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• v.11C no.3
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• pp.401-408
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• 2004

The Bluetooth Scatternet based on tree structure has several merits such as small numb of links and simple routing method. This paper proposes an algorithm which satisfies the constraints of Bluetooth Specification and forms the topology of scatternet as close as the tree structure that has the shortest average inter-node distance among trees. Also we show that the proposed method reduces the average hop count between any two devices compared to early works without higher formation delay by a simulation.

• Journal of Communications and Networks
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• v.18 no.2
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• pp.238-245
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• 2016

A sequence number checking technique is proposed to improve the performance of TCP connections in mobile ad hoc networks. While a TCP connection is initialized, a routing protocol takes the responsibility for checking the hop count between a source and destination pair. If the hop count is greater than a predefined value, the routing protocol decides to use a proxy node. The responsibility of a proxy node is to check the correctness of data packets and inform the missing packets by sending an acknowledgement from a proxy node to the source node. By doing so, the source node is able to retransmit any missing packet in advance without waiting until an end-to-end acknowledgement is received from the destination. Simulation results show that the proposed mechanism is able to increase throughput up to 55% in static network and decrease routing overhead up to 95%in mobile network.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.1
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• pp.64-71
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• 1999

본 논문에서는 공중 광역 ATM망 환경에서 비연결형 서비스 제공에 사용되는 CLS에 적용될 수 있는 홉 카운터를 이용한 우선 순위 제어 알고리즘(Priority Control Algorithm using Hop-Count : HC-PC)의 망 자원 손실 비용을 분석하였다. 분석을 통해 우선 순위가 없을 경우 (No Priority Controls Algorithm: NO-Pc) 의 평균 셀 손실률이 HC-PC 의 평균 셀 손실률의 가중 평균보다 크거나 같은 경우 항상 NO-PC 이 평균 망 자원 손실 비용이 HC-PC 의 평균 망 자원 손실 비용에 비해 크다는 사실을 보였다. 시뮬레이션 결과는 분석에 의해 찾아진 조건이 만족됨을 보여주며 HC-PC가 NO-PC에 비해 어떠한 환경에서든지 항상 낮은 평균 망 자원 손실 비용을 가짐을 보여 준다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.18-18
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• 1995

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12B
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• pp.1535-1541
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• 2009

In this paper, we suggest an efficient path searching algorithm that reduces the hop count when each node sends a data in ZigBee networks. As the hop count reduces, the network traffic is also reduces and leads to less energy consumption. This enables the sensor network live longer with limited node power. The proposed path searching algorithm consists of two sub-algorithms. One for upstream process and the other for downstream process. When a node selects its proper routing path, the node not only uses the information of the parent and child node, but it also uses the neighbor nodes for each node. In the simulation, we changed various network environment factors such as network parameters, number of nodes, and number of neighbor nodes and observed their performances. We compare the performance to the previous ZigBee Tree routing algorithm with separate two algorithms, the upstream and the downstream, and then compare the performance when all two algorithms are applied.