• Journal of Advanced Marine Engineering and Technology
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• v.33 no.1
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• pp.120-130
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• 2009

In recent years, many mobile wireless communication devices and applications have been deployed on the planet. The mobile multi-hop wireless network models appeared to provide means to access to networks where few infrastructure exists. However, the mobile multi-hop wireless networks have weaker points in attacks and intrusions than the wired and one-hop wireless networks. In this paper, the secure routing issues in most mobile multi-hop wireless network models are surveyed in depth. The state-of-the-art technologies and research activities are explained. Finally, the issues and technologies for the secure routing specific to a maritime network model are sufficiently discussed as conclusions.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.153-156
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• 2003

Conventional simulations for mobile ad hoc network so far are based on the "random walk" of the mobile nodes, which are not constrained by their surrounding spatial environments. In this paper, we present a geography-based mobility model, which reflects more realistic movements of the real world. This mobility model is used for performance evaluation of MANET routing protocols.protocols.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.5
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• pp.775-784
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• 2008

It is not easy to access very high speed Internet services at sea due to some technical and economical problems. In order to realize the very high speed Internet services at sea like on land, new communication network models based on MANET should be adopted. In this paper, a new MANET model at sea is provided, which considered the ocean environments, and the characteristics and movement of vessels. On the basis of the fact that most vessels navigate on the predetermined courses, which are the shortest paths between source and destination ports in most cases, a type of location oriented routing protocol is proposed in this paper. The Hybrid Course-Based Routing Protocol(HCBR) makes use of the static information such as courses and positions of ports to proactively find the shortest paths not only among ports but also the cross points of courses. HCBR also makes use of the locational information of vessels obtained via GPS and AIS systems to reactively discover the shortest route by which data packets are delivered between them. We have simulated the comparison of the performance of HCBR with those of LAR scheme 1 and scheme2, the most typical protocols using geographical information. The simulation results show that HCBR guarantees the route discovery even without using any control packet. They also show that HCBR is more reliable(40%) and is able to obtain more optimal routes(10%) than LAR scheme1 and scheme2 protocols.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.05a
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• pp.781-784
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• 2008

최근 멀티미디어 콘텐츠가 빠르게 확산되고, 초고속 광대역 IP 네트워크 기술이 발전하면서 통신과 방송의 독자적 개별 서비스가 서로 공존하여 통합융합 서비스로 진화발전하고 있다. 대표적 방송/통신융합 서비스인 IPTV는 통합융합서비스의 가장 강력한 응용분야이며, IPTV와 같은 서비스들이 증가함으로 인해 다양한 인터넷 서비스를 구현하기 위해서 인터넷 프로토콜을 통한 고화질의 데이터 처리에 대한 관심이 통신업계의 화두로 등장하고 있다. 본 연구에서는 소규모에서 사용되는 표준 라우팅 프로토콜인, RIP 환경과 대규모 자율 네트워크에서 사용되는 링크 상태 라우팅 프로토콜인, OSPF 환경을 구현하여 IPTV 서비스 중에서 방송 화질의 PSNR값으로 성능을 측정하고 평가하여 효율적인 IPTV 서비스를 위한 네트워크 구축 방안을 제시하고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.572-575
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• 2009

With the advent of integration environment of broadcasting and communication, IPTV has been widely used. It provides services such as information, movie contents and broadcasting through TV using super-high speed networks. Developments of Wireless LAN and IP network technology create various and fusional services such as IPTV, VoIP that are based on IP network. The development of Wireless LAN is very important in IPTV network field which requires the best quality of service on the security, QoS and bandwidth. In this Paper, We configure the experimental network in its RIP and OSPF environment to test the Video Quality of IPTV in Wireless LAN. We measure and evaluate broadcasting quality by using PSNR to show the corelation of Routing Protocols in Wireless LAN in which how they affect to the IPTV real-time Video Quality.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.8
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• pp.1505-1510
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• 2008

In large-scale wireless sensor networks, the deployed nodes cannot be replaced or recharged after first deployment. Also, dead nodes maγ lead to the partition of whole networks. While performing data dissemination under a battery power constraint, energy efficiency is a key design factor of routing protocol. As a solution for the efficient data dissemination, in this paper, we propose a protocol namely Hierarchical Data Dissemination (HDD) which provides scalable and efficient data delivery to multiple sources and mobile sinks. HDD uses the facts that sink nodes are central gathering Points and source-centric data forwarding paths are constructed and it is maintained with two-tier communications. The performance of HDD is compared with TTDD about the energy consumption, data delivery time and data success ration. The extensive simulation results show that HDD Routing Protocol outperforms TIDD by more than $1.5{\sim}3times$ on energy consumption.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.6
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• pp.1113-1119
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• 2008

In IP-USN for replacing the sensor network based on Zigbee by IP-based it, routing and the address assignment technique for sensor node are important focuses. But, there is a weak point in existing hierarchical routings. It is that all paths must be searched because the end node isn't considered. And the end node based muting is not sufficient in the mobile sensor network environment because it supports the only simple-path-search. Hereupon, this thesis suggests ComHRP(Complement HRP) that have the only merits of existing methods. The address assignment technique and search method are also proposed. ComHRP simplifies the organization of sensor networks and reduces network complexity. Also, It can efficiently deal with restructuring networks for the unpredictable ubiquitous sensor network feature.

• Smart Media Journal
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• v.5 no.1
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• pp.55-60
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• 2016

Mobility of the sensor networks proposed a new way to the efficient design of sensor networks and improvement of network system performance. Mobility results in a number of functional changes in the MAC protocol and routing protocol. Especially, the mobility of the nodes may occur the increase of the overhead of transmission or disconnection of the link. Therefore, the study of the energy efficient transmission is very important in mobile sensor networks. This paper proposed adaptive transmission mechanism on the distance-based power control. The proposed mechanism was analyzed better than conventional method in the average energy consumption and network life by simulation results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.8
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• pp.1729-1735
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• 2009

The hierarchical routing could cause a lot of energy consumption for transferring data by assigning hierarchical routes although actual nodes could be located in physically near spots. Also, when Node Failure or Association Error occurs, the Hierarchical routing could waste more energy to deliver the control messages. This paper evaluate performance of SHP(Shortest Hop Routing) algorithm that suggests short-cut routing algorithm using NL(Neighbor List) and Redirect_ACK message to improve problem of hierarchical routing algorithm. We do a computer simulation by the size of network, deployment of sensor nodes, sink position and POS. As a result of simulation, SHP has better performance than Zigbee Hierarchical routing and HiLow.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06d
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• pp.115-117
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• 2006

IEEE 802.11 표준은 채널 상태에 따라 다양한 전송 속도를 지원하며, 무선랜 환경에서 이러한 특성을 활용하는 연구들이 진행되어 왔다. 그러나, 모바일 애드 혹 네트워크 환경에서 다중전송속도를 활용하는 연구는 거의 이루어지지 않았다. 본 논문은 모바일 애드 혹 네트워크에서 동적으로 다중전송속도를 활용하여 채널 효율을 높이는 알고리즘을 제안한다. 제안 기법은 MAC 계층과 네트워크 계층 중간에 위치하며 각 계층에 독립적으로 동작한다. 라우팅 프로토콜에서 결정한 다음 홉에 더불어, 제안 기법은 더 빠른 전송 속도를 갖는 중계 경로를 탐색한다. 또한, 패킷의 크기에 따라 경쟁 부하를 고려하여 선택적으로 전송 경로를 변경한다. 모의 실험을 통한 성능 평가는 제안 기법의 우수한 성능을 입증한다.