• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.10C
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• pp.902-911
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• 2002

A wireless ad-hoc network is a collection of wireless mobile hosts forming a temporary network without the aid of any centralized adminstration or standard support services. Wireless ad-hoc networks may be quite useful in that they can be instantly deployable and resilient to change. In this environment, for many crucial distributed applications, it is necessary to design robust virtual infrastructures that are fault-tolerant, self-stabilized, and resource-efficient. For this task this paper proposes a scheme of maintaining robust spanning trees which are little affected by topological changes. By maintaining such a spanning tree and adapting it to the environments with frequent topological changes, one can improve the reliability and efficiency of many applications that use the spanning tree.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.9
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• pp.1665-1671
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• 2007

Mobile Ad hoc Networks (MANETs) refer to autonomous networks in which wireless data communications are established between multiple nodes in a given coverage area without a base station or centralized administration. Because of node mobility and limited battery life, the network topology may changes frequently. Selecting the most reliable path during route discovery process is important to improve performance in ad-hoc networks. In this study, we proposed an enhanced routing protocol based on AODV by monitoring variation of receiving signal strength. New metric function that consists of node mobility and hops of path is used for routing decision. From extensive experiments by using NS-2, The performance of the proposed routing scheme has been imp개ved by comparison to AODV protocol.

• Journal of KIISE:Information Networking
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• v.32 no.1
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• pp.100-109
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• 2005

A Mobile Ad-Hoc Network (MANET) supports a multi-hop wireless network without any prepared base station (BS). The MANET is capable of building a mobile network automatically without any help from DHCP servers for address allocation or routers to forward or route messages. Many routing protocols have been proposed for the MANET, but these specify the most optimized or shortest path from a source to a destination, and they assume that nodes are pre-configured before communication. To make up for this, address allocation algorithms, such as MANETConf [1] and prophet address allocation algorithm [2], have been proposed. Especially, MANETConf proposes address allocation algorithm with duplication address check. In this paper, we present a dynamic node configuration protocol based on 2-tierd hierarchical network architecture for mobile ad-hoc network, modified from [1]. Especially, it reduces the number of broadcast message exchange between nodes when a new node somes into a network, which lessens network overhead, remarkably. This protocol is based on two-tired structure, and it ensures address allocation with simple duplication address defection mechanism.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.1199-1202
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• 2006

대규모 무선 이동 Ad-hoc 네트워크 환경에서는 고정 인프라가 구축된 이동통신 시스템과는 달리 노드의 이동, 에너지 문제 및 에러 등 예외적인 상황 변화로 인한 문제가 다른 네트워크에 비해 잦은 문제가 발생 할 수 있다. 네트워크 환경에 따른 적합한 경로 설정 알고리즘을 선택하고 소스 노드에서 목적지 노드로의 패킷 전송을 위한 경로 설정 후 에러 발생 시 사라진 경로 복구를 위한 최적 경로 재설정 방법 및 효율적 전송 방법을 제안한다. 대규모 이동 노드로 구성된 Ad-hoc 네트워크에서 효율적인 전송 프로토콜인 DSR 라우팅 프로토콜을 이용하고, 에러 발생으로 인한 경로 재설정 시 빠른 경로 복구를 위한 제안된 경로 재설정 방법을 통하여 패킷 전송 지연을 최소화 할 수 있다. 제안된 경로 재설정 방법은 규모가 클수록 기존 방법보다 효과가 큰 경로 재설정 방법이다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.191-194
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• 2006

본 논문에서는 이동 통신망하에서의 Ad Hoc 네트워크에서의 프로토콜을 분석 비교하고, 유비쿼터스 환경하에서의 Ad Hoc 환경하에서의 정보보안 대책을 분석하고자 한다. 이러한 분석을 통하여 차세대 멀티미디오통신하에서의 유선망과 이동망과의 정보를 교환할 대 발생할 수 있는 데이터의 정보를 보호 할 수 있는 알고리즘과 프로토콜을 제안하고 분석한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.400-401
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• 2014

본 논문에서는 이동 에드혹 네트워크(Mobile Ad hoc Network: MANET)에서의 상황인식 기반의 스케쥴링 기법인 DDV(Dynamic Direction Vector)-hop알고리즘을 제안한다. 기존 MANET에서는 노드의 이동성으로 인한 동적 네트워크 토폴리지, 네트워크 확장성 결여의 대한 취약성을 지니고 있다. 본 논문에서는 계층적 클러스터 단위의 동적인 토폴로지에서 노드가 이동하는 방향성 및 속도에 대한 노드의 이동 속성 정보를 고려하여 클러스터를 생성 및 유지하는 DDV-hop 알고리즘을 제안한다. 제안된 알고리즘은 클러스터 헤드노드를 기준으로 클러스터 멤버노드의 방향성 및 속도의 속성 정보를 비교하여 유사한 노드간 클러스터링을 구성하고, 이로부터 헤드노드를 선택하는 방법이다. 실험결과, 제안하는 알고리즘이 네트워크의 부하를 감소시키고 네트워크 토폴로지를 안정적으로 유지할 수 있음을 확인하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.1079-1081
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• 2011

컨테이너터미널 장치장 내 교차로에서 무인 YT(Yard Tractor)간 충돌방지를 위하여 RFID(Radio Frequency Identification) 태그와 ad-hoc 네트워크를 이용한 교차로 충돌방지 알고리즘을 제안한다. 또한 ad-hoc 네트워크 라우팅 프로토콜은 장치장 교차로에서 충돌방지를 위한 YT 간 통신성능을 결정하는 중요한 요소로써, 장치장 교차로 환경과 YT의 이동성을 고려하여 프로토콜을 결정해야 한다. 따라서 RFID 태그를 이용한 YT 위치정보와 AODV(Ad hoc On demand Distance Vector) 방식의 Hello 메시지를 이용해서 충돌방지를 위한 ad-hoc 네트워크 라우팅 프로토콜을 제안한다.

• Journal of KIISE:Information Networking
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• v.29 no.5
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• pp.459-465
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• 2002

Ad-hoc networks have the dynamic topology characteristics and most of the applications on ad-hoc networks require the group communication capability. Previously proposed multicast mechanisms on mobile ad-hoc networks build multicast-infrastructures like the tree or mesh for the group communication and these infrastructures nay cause significant overhead especially in a highly dynamic mobile ad-hoc network environment. Therefore, in this paper, we propose a new multicast mechanism supporting multicast services based on only the underlying unicast routing tables, hence any multicast-related infrastructures like trees and meshes are not required to be constructed.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.1
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• pp.92-101
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• 2012

Security support is a significant factor in ad hoc networks. Especially in dynamic topologies, key agreement with private key updating is essential in providing a secure system. And it is also necessary to protect the identities of individual nodes in wireless environments to avoid personal privacy problems. However, many of the existing key agreement schemes for ad hoc networks do not consider these issues concurrently. This paper proposes an anonymous ID-based private key update scheme and a key agreement scheme for mobile ad hoc networks. We also suggest a method of rekeying between different domains using service-coordinators. These schemes are secure against various attacks and are suitable for service-oriented mobile ad hoc networks.

• Journal of the Korea Society of Computer and Information
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• v.11 no.6 s.44
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• pp.221-226
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• 2006

An Ad hoc network, differently from wired networks, is a self organized network of mobile nodes in wireless environments. In this kind of routing and operation environments. link breaks occur frequently. Knowing positions of nodes may prevent or recover this type of phenomenon. Typically, GPS is used to detect position of nodes but high cost and complexity of construction limit applications. In this paper, we propose and design a method of construction nodes' position map using only information of all nodes without GPS. The proposed method complements and overcomes previous system with software solutions. Hence, construction and operation are simple, and can decrease cost of construction expenses.