• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5B
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• pp.480-488
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• 2009

A mobile ad-hoc network is an autonomous collection of wireless mobile nodes that organizes a temporary network without any network infrastructure. Due to node mobility, it is a challenging task to maintain the network topology. In this paper, we propose a stable clustering algorithm that uses node mobility for cluster formation. In the proposed algorithm, the node mobility is measured by counting the number of nodes entering into/leaving from its transmission range. The node having the lowest mobility is selected as a cluster head. For topology maintenance with reduced control overhead, the cluster head adaptively controls the broadcasting period of hello message to the measured node mobility. Through computer simulations, it is verified that the proposed algorithm outperforms previous clustering algorithms in terms of control overhead, the rate of node mobility changes and the number of cluster head changes.

• Journal of the Korea Society of Computer and Information
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• v.14 no.12
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• pp.109-117
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• 2009

In this paper, we propose an efficient service discovery scheme that combines peer-to-peer caching advertisement and node ID-based selective forwarding service requests. P2P caching advertisement quickly spreads available service information and reduces average response hop count since service information store in neighbor node cache. In addition, node ID-based service requests can minimize network transmission delay and can reduce network load since do not broadcast to all neighbor node. Proposed scheme does not require a central lookup server or registry and not rely on flooding that create a number of transmission messages. Simulation results show that proposed scheme improved network loads and response times since reduce a lot of messages and reduce average response hop counts using adaptive selective nodes among neighbor nodes compared to traditional flooding-based protocol.

• 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.31 no.1
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• pp.81-90
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• 2004

A Mobile Ad Hoc Network (MANET) is a collection of wireless mobile nodes dynamically self-organizing in arbitrary and temporary network topologies without the use of any existing network infrastructure. The AODV (Ad Hoc On-Demand Distance Vector) Protocol is one of the typical reactive routing protocols, in that mobile nodes initiate routing activities only in the presence of data packets in need of a route. In this paper, we focus upon the local repair mechanism of AODV. When a link is broken, the upstream node of the broken link repairs the route to the destination by initiating a local route discovery process. The process involves the flooding of AODV control messages in every node within a radius of the length from the initiating node to the destination. In this paper, we propose an efficient local repair scheme for AODV called AFLRS (AODV-based Fast Local Repair Scheme). AFLRS utilizes the existing routing information in the intermediate nodes which have been on the active route to the destination before a link break occurs. AFLRS can reduce the flooding range of AODV control messages and the route recovery time because it can repair route through the intermediate nodes. For the performance evaluation of the proposed AFLRS, we have simulated the local repair mechanisms by using NS2 and AODV-UU. The performance results show that AFLRS can achieve faster route recovery than the local repair mechanism of AODV.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9B
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• pp.947-954
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• 2009

In mobile ad hoc networks, service discovery to search for an available service is an important issue. In this paper, we propose an efficient service discovery protocol that is combined a dht-based service discovery scheme and a P2P caching-based information spreading scheme. Proposed scheme store key information in hashed zone and search services using it's information. To search quickly a service, it use its physical neighbors information which collected by 1-hop hello message between a node and its physical neighbors. We do not use a central look up server and do not rely on flooding. Hence, it uniquely balanced all node's load in mobile ad hoc networks and reduced the number of messages exchanged, network load and response time. The simulation results show that our protocol outperforms DHT-based and flooding protocols.

• 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.