• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.5
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• pp.1-6
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• 2009

MANET(Mobile Ad-hoc NETwork), a network characterized that its moving nodes freely constructs Network topology, has other different characteristics. Because Policy based Network Management in MANET guarantees QoS between nodes, it is essential in applied areas like VANET which targets safety and convenience. In this paper, we use COPS-PR which is appropriate Policy Exchange Protocol for MANET, and implement DiffServ-based QoS in the real networks and experiment its capability.

• Proceedings of the Korea Multimedia Society Conference
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• 2012.05a
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• pp.440-441
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• 2012

애드훅 네트워크는 이동성을 가지는 다수의 노드들에 의해서 자율적으로 구성되는 임시적 네트워크이다. 기존의 기반망을 사용하지 않기 때문에 기존의 기반망을 이용할 수 없거나 설치가 어려운 곳에서 네트워크 구성하는 장점으로 많은 연구가 이뤄져 왔다. 하지만 경로 구성시에 보안이 이뤄지지 않을 경우 악의적인 노드를 이용하여 다른 정보나 네트워크를 사용하지 못하게 되는 경우가 발생한다. 이를 위한 연구가 진행되어 왔지만 아직도 많은 문제점을 있다. 본 논문에서는 빠르게 적용할 수 있는 대칭키 기반에 전방향 보안성을 고려한 기법을 제안하고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.393-395
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• 2011

본 논문은 에드 혹 네트워크(Ad hoc network)에서 각 노드는 베터리 기반의 한정된 에너지로 동작 하기 때문에 에너지 효율을 높이기 위한 다양한 라우팅 알고리즘이 연구되고 있다. 에드 혹 네트워크는 많은 수의 노드들이 거리 등의 상호 속성 정보에 의한 노드의 관리 기법에 따라 노드의 에너지를 관리해야 한다. 또한 주어진 망에서 관리 노드 또는 중계 노드 등의 동작 불가능한상태가 되었을 경우 라우팅 경로가 끊어짐으로서 통신이 불가능한 상태가 되는 문제점이 있다. 본 논문에서는 트리망에서 중계 노드로 사용되는 클러스터 헤드 노드가 동작 불가능한 상태가 되었을 경우, 노드의 위치정보를 이용하여 새로운 헤드 노드를 선출하는 ECOPS(Energy conserving Optimal Path Schedule) 알고리즘을 제안 하였다. 특히 제한된 ECOPS 알고리즘을 이용함으로 노드에 대한 라이프타임을 향상 시키고 전체 라우팅 경로가 오랜 시간 동안 지속되는 결과를 보여 주었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.501-502
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• 2009

본 연구는 mobile IP에서 smooth handoff의 지연 요소를 최대한 줄이기 위해 지역 관리 방식의 FA를 사용하여 성능을 향상시키는 방안에 대해 연구하였다. 본 연구에서는 전송지연, 처리율 등의 분석을 실시하였으며 모든 FA에 버퍼를 내장한 방식과 지역관리용 FA를 이용한 방식에 대하여도 각종 성능을 측정하여 기존의 방식에 비해 어느 정도 성능 향상이 있는지 확인하였다. 본 연구를 통해 지역관리 기능을 수행하는 GFA를 핸드오프 발생 간격이 25초 이상에서는 바인딩 시간 단축에 의한 효과가 있음을 확인할 수 있었다. 이와 같은 연구 결과를 실제 무선 인터넷망 구축에 활용한다면 무선 인터넷망 구축에 관한 관련 자료가 많지 않은 현 상황에서 FA와 MN의 용량과 성능을 결정하는데 보탬이 될 것으로 확신한다.

• The KIPS Transactions:PartD
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• v.12D no.2 s.98
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• pp.259-266
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• 2005

Recently data centric routing or application dependent routing protocols are emerged in mobile ad hoc networks. In this paper, we propose a routing method for query processing in MANET(Mobile Ad hoc NETwork) environment, called road-based query routing, with consideration on real time traffic information of large number of vehicles. In particular, we focus on the method that process arrival time dependent shortest path query in MANET without a central server on the road networks. The main idea of our approach lies in a routing message that includes query predicates based on the road connectivity and on data gathering method in real time from vehicles on the road by ad-hoc network. We unify route discovery phase and data delivery(query processing) phase in our mechanism and reduce unnecessary flooding messages by pruning mobile nodes which are not on the same or neighboring road segments. In order to evaluate the performances of the proposed method, we established a model of road networks and mobile nodes which travel along the roads. The measurement factor is the number of nodes to whom route request is propagated according to each pruning strategy. Simulation result shows that road information is a dominant factor to reduce the number of messages.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.6
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• pp.12-20
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• 2008

Recent wireless communication technologies are envisioned as an innovative alternative to solve transportation problems. On ad hoc networks, as a wireless communication technology, nodes can communicate data without any infrastructure. In particular, vehicular ad hoc networks (VANETs), a specific ad hoc network applied to vehicles, enable vehicles equipped with a communication device to form decentralized traffic information systems in which vehicles share traffic information they experienced. This study investigated traffic information dissemination in a VANET-based traffic information system. For this study, an integrated transportation and communications simulation framework was developed, and experiments were conducted with real highway networks and traffic demands. The results showed that it took 3 minutes in the low traffic density situations (10 vehicle/lane.km) and 43 seconds in the high traffic density condition (40 vehicle/lane.km) to deliver traffic information of 5km away with 10% market penetration rate. In uncongested traffic conditions, information seems to be disseminated via equipped vehicles in the opposite direction. In congested traffic conditions, the sufficient availability of equipped vehicles traveling in the same direction reduces the chance to use vehicles in the opposing direction even though it is still possible.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.9
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• pp.1829-1836
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• 2009

A wireless Ad-hoc network is willing to send and receive data and for other nodes, and it is a temporal network where the nodes with mobility are automatically constituted. This network has been studied to construct networks in the state where there is no infrastructure. The limited nodes and its frequent moving in a wireless Ad-hoc network have resulted in frequent network disconnection. Therefore, the data transmission rate should be secured in a wireless Ad-hoc network. This study proposes the method to improve QoS of data transmission considering the mobility of nodes that respond to path searching by means of AOMDV routing protocol. By applying the suggested method, it is possible to raise the transmission rate by improving the reliability of transmission path.

• The KIPS Transactions:PartC
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• v.11C no.7 s.96
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• pp.871-878
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• 2004

Recenty, there has been great interest in MANET from various areas. In this paper we focus on performance analysis of on demand routing protocols surf as DSR, AODV, and TORA in MANET. We have conducted several simulations concerned with application service data such as sensor, text. voice, and video data. And then, we have evaluated the performance of three protocols in a pre-designed ad hoc network, which is consisted of 20 nodes. As a result, we have obtained quantitative data for packet delivery fraction, average end to-end delay, routing load, channel utilization from upper layer and supportable routing protocol for application service data. The results can be used for designing specific-purposed ad-hoc networks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12B
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• pp.805-810
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• 2005

According to the user requirements for continuous and real-time multimedia information, the concept of Quality of Service (QoS) has emerged as a main issue in mobile ad-hoc networks. QoS routing is to find the route that meets the QoS requirements of the users. In this paper, we propose a routing protocol that is based on AODV over TDMA, one of the typical routing protocols for mobile ad-hoc networks, by making a bandwidth reservation for QoS guarantee. While the existing schemes calculate the maximum available bandwidth for each candidate path, our scheme is to check only if the bandwidth of a given path satisfies the end-to-end QoS requirement and then to make a reservation by allocating time slots efficiently in the wireless environment. In order to evaluate the performance of the proposed QoS routing protocol, some simulations are carried out in the ad-hoc environment.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.6
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• pp.243-248
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• 2013

With rapid growth and fast diffusion of smartphone technologies, many users are deeply concerned about the smart applications and many mobile applications converged with various related technologies are rapidly disseminated. Especially, the convergence technologies like mobile apps that can establish the wireless ad hoc network between smartphone and other peripherals and exchange data are appear and progressed continuously. In this paper, we design and implement the smart app using bluetooth based wireless ad hoc sensor network that can connect smartphone with sensors and exchange data for various smart applications. The proposed smart application in this paper collects data obtained from more than 2 multi-sensors in real time and fulfills the decision making function by storing data at the database and analysing it. The smart application designed and implemented in this paper is the healthcare application that can analyze and evaluate the patient's health condition with sensing data from multi-sensors in real time through bluetooth module.