• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.541-542
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• 2009

MANET은 유선 기반망의 도움 없이 무선 노드들 간에 서로 협력하여 다중-홉으로 정보를 주고 받을 수 있도록 해주는 네트워크이다. 최근 MANET과 인터넷 망과의 통신이 요구되고 있고 이를 위해 무선 노드가 글로벌 IP 주소를 할당 받을 수 있어야 한다. 본 논문에서는 인터넷 게이트웨이를 통해 인터넷 망과 연결된 MANET 구조에서 무선 노드가 빠르게 글로벌 IP 주소를 설정할 수 있는 기법을 제안한다. 제안하는 기법의 성능 평가를 위해 NS-2로 실험을 수행했으며, 그 결과 기존 방법보다 빠르게 글로벌 IP 주소를 설정하고 네트워크 부하를 감소 시킬 수 있음을 입증하였다.

• Journal of the Korea Society of Computer and Information
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• v.12 no.6
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• pp.219-228
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• 2007

End-to-end path setup and maintenance are very important for mobile ad-hoc wireless communications, because of the mobility and the limited battery capacity of the nodes in the networks. the AODV routing protocol is the one of mary proposed protocols. However, there are route failure problem with the Proposed protocols between intermediate nodes due to such mobility and exhausted battery characteristics, and this is because only the shortest hop count is considered for the route setup. If route failure happens. Problem such as the waste of bandwidth and the increment of the energy consumption occur because of the discarding data packets in the intermediate nodes and the path re-setup process required by the source node. In addition, it obviously causes the network lifetime to be shortened. This paper proposes a routing protocol based on the AODV routing protocol that it makes use of the remaining energy, signal strength and SNR of the MAC layer resources to setup a path.

• Journal of the Korea Society of Computer and Information
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• v.17 no.5
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• pp.41-48
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• 2012

A Vehicular Ad-hoc Network (VANET) is a vehicular specific type of a mobile ad-hoc network, to provide temporary communications among nearby vehicles. Mobile node of VANET consumes energy and resource with participating in the member of network. In a VANET, data replication and cooperative caching have been used as promising solutions to improve system performance. Existing cooperative caching scheme in a VANET mostly focuses on weak consistency is not always satisfactory. In this paper, we propose an efficient cache management scheme to maintain strong data consistency in a VANET. We make an adaptive scheduling scheme to broadcast Invalidation Report (IR) in order to reduce query delay and communication overhead to maintain strong data consistency. The simulation result shows that our proposed method has a strength in terms of query delay and communication overhead.

• Journal of KIISE:Information Networking
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• v.35 no.5
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• pp.409-414
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• 2008

In mobile ad hoc networks, most of on demand routing protocols such as DSR and AODV do not deal with traffic load during the route discovery procedure. To solve the congestion and achieve load balancing, many protocols have been proposed. However, the existing load balancing schemes has only considered avoiding the congested route in the route discovery procedure or finding an alternative route path during a communication session. To mitigate this problem, we have proposed a new scheme which considers the packet bursting mechanism in congested nodes. The proposed packet bursting scheme, which is originally introduced in IEEE 802.11e QoS specification, is to transmit multiple packets right after channel acquisition. Thus, congested nodes can forward buffered packets promptly and minimize bottleneck situation. Each node begins to transmit packets in normal mode whenever its congested status is dissolved. We also propose two threshold values to define exact overloaded status adaptively; one is interface queue length and the other is buffer occupancy time. Through an experimental simulation study, we have compared and contrasted our protocol with normal on demand routing protocols and showed that the proposed scheme is more efficient and effective especially when network traffic is heavily loaded.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06d
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• pp.105-108
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• 2011

OLSR(Optimized Link State Routing) 프로토콜은 모바일 애드 혹 네트워크(Mobile Ad hoc Networks)에서 사용되는 프로액티브(proactive) 프로토콜이다. OLSR에서는 각 노드가 자신의 MPR(multi-point relay) 노드를 선정하고, MPR 노드를 통해 모든 메시지를 전달한다. 만약 공격자가 네트워크 정보를 조작 하여 자신이 다른 노드들의 MPR로 선정되도록 한다면, 공격자는 주변의 노드의 메시지를 폐기시킬 수 있다. 본 논문에서는 이러한 OLSR의 취약점을 보안하기 위한 SE-OLSR(Secure Enhanced OLSR) 프로토콜을 제안한다.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.4
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• pp.433-438
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• 2014

The demanding in construction of the stand-alone networks and interconnection between convergence devices have led an increase in research on MANET and the application of MANET has been paid much attention as a Ubiquitous computing which is growing fast in the field of computer science. With performance both as hosts and routers, easy network configuration, and fast response, mobile nodes participating in MANET are suitable for Embedded computing but have vulnerable points, about lack of dynamic network topology due to mobility, network scalability, passive attacks, and active attacks which make it impossible to manage continuous security authentication service. In this study, proposes S-EKE authentication mechanism for a robust authentication based on MANET and through identify wireless environment security vulnerabilities, currently being used in OTP S/Key and DH-EKE analyzes.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.17-22
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• 2013

In this paper, we propose a multi-hop cooperative transmission protocol over Rayleigh fading channels. In the proposed protocol, the multi-hop cooperative transmission is used to improve the system performance. Due to broadcast nature, we do not limit the receiving node to be only the next node, but the destination and all the nodes between the transmitting node and the destination. The proposed protocol can hence save the average transmit power, compared with multi-hop direct transmission protocol due to the skipped transmissions from some intermediate nodes or chosen relays. The proposed scheme is implemented and evaluated in mobile ad-hoc wireless networks.

• Journal of Digital Convergence
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• v.14 no.9
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• pp.309-315
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• 2016

The node mobility in the wireless mobile network environment increases the energy consumption. This paper proposes a CNMA (cluster-based node management algorithm) to reduce the energy consumption caused by node mobility, and to prolong the life cycle for cluster member nodes. The proposed CNMA traces the mobility for nodes between cluster header and member, and it analyses the energy capacity as monitoring periodically their relationship. So, it makes a division and merges by analysing the state transition for nodes. This paper is to reduce the energy consumption due to the node mobility. The simulation results show that the proposed CNMA can efficiently control the energy consumption caused by mobility, and it can improve the energy cycle.

• Journal of Korea Multimedia Society
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• v.11 no.10
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• pp.1376-1384
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• 2008

Numerous researches on network self-configuration have been conducted on Wireless Sensor Network (WSN) and Ad Hoc network but the results have not been applied yet for factory automation. This paper presents development of intelligent process management systems conducting process monitoring and control irrelevant to physical position of a plant operator. The systems are indispensable for diagnosis of rotating machines which cannot exploit wired network. The system was implemented in a Personal Digital Assistant (PDA) using Bluetooth communication protocol. When a mobile terminal reaches to communication range of the process management server, the server detects the mobile terminal to reconfigure plant network automatically. The server authenticates a user of the terminal to download and installs monitoring and control program considering authorized level of the user. If the terminal leaves communication range of the server, it deletes the node from the network and removes the program automatically to save resources and prevent security problems such as missing terminal. Operation of developed functions was verified in a testbed emulating steel-making plant.

• Journal of Korea Spatial Information System Society
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• v.10 no.3
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• pp.45-54
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• 2008

This paper designs and Implements a connectivity analyzer for the hybrid vehicular network based on the real-life movement history data achieved from the Taxi telematics system currently in operation, aiming at providing a useful guideline and information to build a telematics network. The simulator traces the location of each vehicle, sets the vehicle type, either gateway or normal, decides whether it can be connected to a mobile gateway, keeps track of status of the vehicle, and calculates the duration of disconnected state. With this analysis considering the transmission range and gateway ratio, we can decide the cost-effective number of mobile gateways having both cellular and ad-hoc network interfaces, and buffer space requirement based on the measured disconnection time and message generation ratio.