• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.749-753
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• 2006

최근 Mobile Ad-hoc Networks(MANET)에서 보안 요소를 추가한 라우팅 연구가 활발히 진행되어 왔다. 하지만 기존 연구들은 대부분 secure 라우팅 또는 패킷 자체에 대한 악의적인 행위가 이루어지는 부분 중 어느 한 측면에 대해서만 연구되어져 왔다. 이와 같은 방법들은 악의적인 노드를 확인하더라도 라우팅 경로 설정과정에서 악의적인 행위가 이루어지거나 라우팅 경로 설정에 대한 공격은 차단하더라고 패킷에 대한 악의적인 행위가 이루어지면 네트워크 내 보안 측면에서 큰 효율성을 기대할 수 없다. 따라서 본 논문에서는 일정기간 악의저인 행위가 이루어지는 노드를 확인하여 각 노드에 대한 신뢰단계를 구성 후, 획득한 각 노드의 신뢰레벨에 따라 라우팅 경로를 설정함으로써 패킷 및 라우팅 경로 설정에 대해 이루어질 수 있는 악의적인 행위를 효율적으로 대응 할 수 있는 방안인 IMSec(A identification of malicious node and secure communications in MANET)을 제안한다. IMSec은 AODV(Ad-hoc On-demand Distance Vector Routing)를 기반으로 하였다. NS-2 네트워크 시뮬레이션 결과를 통해, 제안된 IMSec은 기존 프로토콜보다 네트워크의 부하를 감소시킨 상태에서 악의적인 노드를 더 정확하고 신속하게 찾아냄을 보였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.9
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• pp.1267-1270
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• 2021

In this paper, we propose a distributed routing algorithm for mobile ad hoc networks (MANET) where mobile devices can be utilized as relays for communication between remote source-destination nodes. The objective of the proposed algorithm is to minimize the end-to-end communication delay caused by transmission failure with deep channel fading. In each hop, the node needs to select the next relaying node by considering a tradeoff relationship between the link stability and forward link distance. Based on such feature, we formulate the problem with partially observable Markov decision process (MDP) and apply deep reinforcement learning to derive effective routing strategy for the formulated MDP. Simulation results show that the proposed algorithm outperforms other baseline schemes in terms of the average end-to-end delay.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.5B
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• pp.390-396
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• 2006

Policy-based Network Management(PBNM) in the Mobile Ad-hoc network(MANETs) requires additional, reliable and efficient mechanism over PBNM in wired network. Thus, it is important that the management system in MANETs should cluster the moving nodes and manage their movements in an effective manner. In this thesis, I propose a mechanism for the policy-based management in ad hoc networks in which I consider several methods to discover the Policy Decision Point(PDP), set the management area, and manage the movements of Policy Enforcement Point(PEP) nodes in the PBNM system. Moreover, COPS-PR is extended for the mechanism. Finally, I analyze and validate the results through simulations.

• Journal of information and communication convergence engineering
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• v.19 no.3
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• pp.136-141
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• 2021

Research on wireless sensor networks has focused on the monitoring and characterization of large-scale physical environments and the tracking of various environmental or physical conditions, such as temperature, pressure, and wind speed. We propose a stochastic mobility model that can be applied to a MANET (Mobile Ad-hoc NETwork). environment, and apply this mobility model to a newly proposed clustering-based routing protocol. To verify its stability and durability, we compared the proposed stochastic mobility model with a random model in terms of energy efficiency. The FND (First Node Dead) was measured and compared to verify the performance of the newly designed protocol. In this paper, we describe the proposed mobility model, quantify the changes to the mobile environment, and detail the selection of cluster heads and clusters formed using a fuzzy inference system. After the clusters are configured, the collected data are sent to a base station. Studies on clustering-based routing protocols and stochastic mobility models for MANET applications have shown that these strategies improve the energy efficiency of a network.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.2
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• pp.542-558
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• 2016

Vehicular Ad Hoc Networks (VANETs) are self-configuring networks where the nodes are vehicles equipped with wireless communication technologies. In such networks, limitation of signal coverage and fast topology changes impose difficulties to the proper functioning of the routing protocols. Traditional Mobile Ad Hoc Networks (MANET) routing protocols lose their performance, when communicating between vehicles, compromising information exchange. Obviously, most applications critically rely on routing protocols. Thus, in this work, we propose a methodology for investigating the performance of well-established protocols for MANETs in the VANET arena and, at the same time, we introduce a routing protocol, called Genetic Network Protocol (G-NET). It is based in part on Dynamic Source Routing Protocol (DSR) and on the use of Genetic Algorithms (GAs) for maintenance and route optimization. As G-NET update routes periodically, this work investigates its performance compared to DSR and Ad Hoc on demand Distance Vector (AODV). For more realistic simulation of vehicle movement in urban environments, an analysis was performed by using the VanetMobiSim mobility generator and the Network Simulator (NS-3). Experiments were conducted with different number of vehicles and the results show that, despite the increased routing overhead with respect to DSR, G-NET is better than AODV and provides comparable data delivery rate to the other protocols in the analyzed scenarios.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.4
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• pp.493-498
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• 2011

In this paper, Transmission performance over MANET(Mobile Ad-hoc Networks) under DDoS Intrusions is evaluated. Intrusion counterplan requirement, which have to be used for MANET under DDoS intrusions, is suggested through this evaluation. VoIP simulator based on NS-2 network simulator is used for performance measurement. MOS, network delay, packet loss rate and call connection rate is measured with this simulation. Finally, requirement of intrusion continuing time shorter then 10 seconds is suggested for VoIP service over MANETs under DDoS intrusions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.11
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• pp.4701-4719
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• 2015

A Mobile Ad hoc Network (MANET) consists of mobile nodes which co-operate to forward each other's packets without the presence of any centralized authority. Due to this lack of centralized monitoring authority, MANETs have become vulnerable to various kinds of routing misbehaviour. Sometimes, nodes exhibit non-cooperating behaviour for conserving their own resources and exploiting others' by relaying their traffic. A node may even drop packets of other nodes in the guise of forwarding them. This paper proposes an efficient Reputation and Collaboration technique through route-request for handling such misbehaving nodes. It lays emphasis not only on direct observation but also considers the opinion of other nodes about misbehaving nodes in the network. Unlike existing schemes which generate separate messages for spreading second-hand information in the network, nodes purvey their opinion through route-request packet. Simulation studies reveal that the proposed scheme significantly improves the network performance by efficiently handling the misbehaving nodes in the network.

• The KIPS Transactions:PartC
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• v.13C no.4 s.107
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• pp.455-460
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• 2006

Currently, the IETF group is working on service differentiation in the Internet. However, in wireless environments such as Ad-hoc networks, where channel conditions are variable and bandwidth is scarce, the Internet differentiated services are suboptimal without lower layers' support. The IEEE 802.11 standard for Wireless LANs is the most widely used WLAN standard today. 1t has a mode of operation that can be used to provide service differentiation, but it has been shown to perform badly. In this paper, we present a new service differentiation scheme for support QoS in the wireless IEEE 802.11, which is based on a multiple queuing system to provide priority of user's flow. We simulate and analyze the performance of our algorithm and compare its performance with the original IEEE 802.11b protocol. Simulation results show that our approach increases overall throughput in the MAC layer.

• Journal of the Korean Data and Information Science Society
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• v.19 no.2
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• pp.645-655
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• 2008

As wireless connectivity is integrated into many handheld devices, streaming multimedia content among mobile ad-hoc peers is becoming a popular application. In this paper, we propose a dynamic service replication algorithm for providing guaranteed continuous streaming services to all nodes in mobile ad-hoc networks (MANETs). First, a MANET is comprised of logical grid hierarchy, and a streaming service is replicated to a lower server region of the logical grid hierarchy by considering the link availability between a mobile node and the streaming server within a server region or the popularity of the streaming service. We evaluate analytically the performance of the proposed algorithm, and compared with that of existing Qin's algorithm. Evaluation results show that our algorithm can achieve better streaming performance than Qin's algorithm. Therefore, the proposed algorithm not only improves the sharing availability of replicated streaming services but also controls efficiently the number of streaming service replications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.719-721
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• 2010

VoIP over MANET is an important IP phone technique used in mobile ad-hoc networks. VoIP system over wired networks is based on SIP, SIP UA and SIP server which process the users invite, register and so on. Since no base stations in MANETs to perform as SIP servers, VoIP service on MANETs is being done with tiny SIP server which is done on each node. In this paper, VoIP system is implemented with pseudo SIP server which can process 1 call based on modification of standard SIP server which is used on communication environment such as wired networks. The propesed system is performed well and compatible with SIP and SIP UA.