• Journal of IKEEE
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• v.5 no.1 s.8
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• pp.59-66
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• 2001

In this paper, we propose a dynamic source routing protocol supporting asymmetric paths for mobile Ad Hoc networks that contain unidirectional links. At present, the existing dynamic source routing protocol supports only symmetric paths that consist of bidirectional links for routing. However, in fact, there can exist unidirectional links due to asymmetric property of mobile terminals or current wireless environment. Thus, we implement a mobile Ad Hoc routing protocol supporting unidirectional links, which is fit for more general wireless environment. Especially, the proposed protocol uses an improved multipath maintenance method in order to perform rapid route reconfiguration when route error due to mobility is detected. For performance evaluation, we consider the following factors: average route discovery time and average data reception rate. In order to obtain the factors of the performance evaluation, we did simulation for 900 seconds in the step of 100 seconds with the following scenarios: usage of route cache in intermediate nodes on route path, and different mobility/connection patterns.

• Journal of Internet Computing and Services
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• v.5 no.2
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• pp.75-84
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• 2004

Geocasting, a variant of the conventional multicasting problem, is one of communication type in which the data packets are delivered to a group of all nodes within a specified geographical region (i.e., the geocasting region) and is called location-based multicasting(LBM)(l). An Ad-hoc network is a dynamically reconfigurable and temporary wireless network where all mobile devices using batteries as energy resources cooperatively maintain network connectivity without central administration or the assistance of base stations. Consequently, the technique to efficiently consume the limited amounts of energy resources is an important problem so that the system lifetime is maximized. In this paper, we propose a LBPA(Location-Based Power Aware) geocasting algorithm that selects energy-aware neighbor to route a packet towards the target region In Ad-hoc network environments. The method Is such that the energy consumption is balanced among the nodes in proportion to their energy reserves. Through the simulations, the proposed LBPA algorithm shows better results, that is, as good as 40% on the average over the conventional LBM algorithm in terms of the network lifetime.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.119-122
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• 2004

This mobile oriented Ad-hoc network yet steps on development level, related issues and standardization are progressing. This paper presented ad-hoc network's overview and overall property, followed by routing scheme that must be setup for communication between each nodes. Among several routing scheme proposed for standardization, ZRP that is foaled by this paper, is hybrid type algorithm, and only includes advantages of others This paper presented running process and implementation method, result that is made from network simulation, shows analysis of each parameter values's change. Each parameters changed with many differences according to Zone radius and communication node's location from simualtion that was performed changing a number of nodes and a velocity of nodes.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06d
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• pp.58-62
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• 2007

기존의 무선 Ad-hoc 네트워크의 연구는 라우팅기법에 중심으로 이뤄지고 있다. 그러나 기존의 연구들은 네트워크를 구성하는 각 요소들이 우호적이며 상호 협력적인 상황을 가정하여 연구가 이루어지고 있다. 그러나 최근 연구에는 안전한 통신을 보장하기 위한 보안 알고리즘의 필요성에 집중되고 있다. 무선 Ad-hoc 네트워크에서의 악의적인 노드를 식별하는 방안들은 정상적인 노드임에도 불구하고 거짓으로 신고했을 때 확인절차 없이 경로를 재탐색하여 최적의 경로를 변경시킴으로서 최적의 전송환경을 활용하지 못하는 문제점이 있다. 본 논문에서는 다중경로 기반의 보안경로 탐색 프로토콜인 MP-SAR 프로토콜을 이용하여 보안경로에서는 악의적인 노드를 검증하고, 유효한 최단경로를 통해 데이터전송을 하는 기법을 제안하고자 한다. 제안한 기법을 적용함으로써 노드에 대한 신고가 있을 때 확인과정을 거쳐 불필요하게 경로를 재탐색하는 과정을 줄일 수 있다.

• Journal of Ubiquitous Convergence Technology
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• v.1 no.1
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• pp.35-41
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• 2007

In mobile ad-hoc wireless networks, one of the most important challenging issues is how to conserve energy, maximizing the lifetime of route(networks) in the view points of both power and mobility of nodes. However, many transmission methods presented in the previous works can not satisfy these two objectives simultaneously. To obtain these two goals, in this paper we propose an architecture to support power saving transmission services with route stability in mobile ad-hoc wireless networks. The proposed architecture consists of two parts, the underlying route stability method to support route(network) lifetime and the power saving transmission methods. The performance evaluation of the proposed architecture is achieved via simulation and analysis.

• Journal of Communications and Networks
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• v.6 no.2
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• pp.156-162
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• 2004

In recent years, mobile ad-hoc networks have received a great deal of attention in both academia and industry to provide anytime-anywhere networking services. As wireless networks are rapidly deployed, the security of wireless environment will be mandatory. In this paper, we describe a group key management architecture and key agreement protocols for secure communication in mobile ad-hoc wireless networks (MANETs) overseen by unmanned aerial vehicles (UAVs). We use implicitly certified public keys method, which alleviates the certificate overhead and improves computational efficiency. The architecture uses a two-layered key management approach where the group of nodes is divided into: 1) Cell groups consisting of ground nodes and 2) control groups consisting of cell group managers. The chief benefit of this approach is that the effects of a membership change are restricted to the single cell group.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2550-2556
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• 2012

We proposed the energy-efficient routing algorithm ALPS (Ad hoc network Localized Positioning System) algorithm that is range-free based on the distance information. The routing coordinate method of ALPS algorithm consists of hierarchical cluster routing that provides immediately relative coordinate location using RSSI(Received Signal Strength Indication) information. Existing conventional DV-hop algorithm also to manage based on normalized the range free method, the proposed hierarchical cluster routing algorithm simulation results show more optimized energy consumption sustainable path routing technique to improve the network management.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.239-243
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• 2011

In wireless ad-hoc network, the detection of link breakage and re-establishing the route path causes lots of network overhead and results in communication delay. In the LBN method, the node causing a link breakage actively sends a message to neighbors so that they can instantly start re-establishing process of new path. In this paper we describe the result of network simulation we performed using NS2 to show the effectiveness of LBN method.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.11a
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• pp.161-164
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• 2005

Mobile device users are sensitive to pay telecommunication charge for downloading Internet data, because the cost is proportional to the amount of data received. If there are device users who want to download the same content, they may cooperate each other to form an ad hoc network and share the partially downloaded content in order to reduce the amount of data downloaded. Each mobile device, called a peer, downloads a specific portion of the whole content using fee-based telecommunication channel, and exchanges the portion with other peers with free ad hoc channel in order that all participating peers are able to reconstruct the whole content in this situation, al1 participating peers become senders and receivers at the same time. In order to distribute the partial content to other peers, the ad hoc network requires a control led distribution mechanism. This paper introduces the per-peer-based distribution method in which one designated peer can transmit partial data to its neighbors at a time. Simulation results show that 90$\%$ of the telecommunication cost is saved with as few as 10 peers .

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.197-200
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• 2011

Many routing protocols have been proposed for low-power and ad-hoc networks where energy awareness and reliability are essential design issues. This paper proposes a dynamic routing protocol for low-power and ad-hoc networks. A dynamic path cost function is defined considering the constraints and characteristics of low-power and ad-hoc networks. The cost function can be applied flexibly depending on the characteristics of the networks. The performance of the proposed method is evaluated using a QualNet network simulator.