• Journal of KIISE:Information Networking
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• v.31 no.6
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• pp.673-684
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• 2004

As the wireless mobile communication is being widespread, mobile technologies will have important roles in the communication with the explosive growth of demanding for wireless portable devices. Among the mobile technologies, a great deal of interest has been taken in mobile ad hoc network (MANET), which is a collection of wireless mobile nodes forming a temporary network without the aid of stationary infrastructure in recent. Furthermore, considering characteristic of ad hoc networks, the design of efficient routing protocols is an important issue. In recent years, on-demand protocols among routing protocols have noticed because of the low routing overhead. However, on-demand protocols suffer from production of the enormous query Packets by broadcasting in order to setup routes, that is, a flooding scheme. The flooding scheme is very costly and results in serious problem, which we refer as the broadcast storm problem. In this paper, we propose a Dynamic Adaptation Query flooding Using Neighbor Topology (NT-DAQ) scheme, in order to resolve the broadcast storm Problem. When a route discovery is in progress, each mobile node decides on the basis of neighbor topology information whether discovery process participates or not. Therefore, our proposed scheme enables to improve network performance in which minimize the number of query rackets. We evaluate the efficiency of our proposed scheme through simulation.

• ETRI Journal
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• v.34 no.5
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• pp.775-778
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• 2012

We propose integrating random network coding with the Enhanced On-Demand Multicast Routing Protocol (E-ODMRP). With the Network Coded E-ODMRP (NCE-ODMRP), we present a framework that enables a seamless integration of random linear network coding with conventional ad hoc multicast protocols for enhanced reliability. Simulation results show that the NCE-ODMRP achieves a nearly perfect packet delivery ratio while keeping the route maintenance overhead low to a degree similar to that of the E-ODMRP.

• Journal of the Korea Computer Industry Society
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• v.6 no.2
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• pp.345-354
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• 2005

Mobile grid can provide the grid service to grid users regardless of space and time. There are many restrictions to use grid service in mobile environment such as battery power of mobile device, movement pattern of mobile device etc. So it is difficult to apply the grid technologies of wired network to wireless network environments. Therefore, to provide the mobile grid service, we suggested the mobile grid architecture using ad-hoc network. Also we showed that hybrid routing protocol is efficient for mobile grid service by considering the battery power of mobile device and simulations of evaluating the delay time of three routing protocols using NS-2. We will study the methods of resource allocations and network reliability to provide the mobile grid service.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.8
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• pp.798-802
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• 2008

In this paper, we consider mobile ad hoc network routing protocols with respect to content sharing applications. We show that by utilizing social relations among participants, our routing protocols can improve its performance and efficiency of caching. Moreover, in certain situation which we can anticipate pattern of user's content consumption, our scheme can help such applications be more efficient in terms of access time and network overhead. Using NS2 simulator, we compare our scheme to DSDV and routing protocol using shortest path algorithm.

• Journal of Communications and Networks
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• v.5 no.3
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• pp.266-274
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• 2003

One of the major issues in current on-demand routing protocols for ad hoc networks is the high resource consumed by route discovery traffic. In these protocols, flooding is typically used by the source to broadcast a route request (RREQ) packet in search of a route to the destination. Such network-wide flooding potentially disturbs many nodes unnecessarily by querying more nodes than is actually necessary, leading to rapid exhaustion of valuable network resources such as wireless bandwidth and battery power. In this paper, a simple optimization technique for efficient route discovery is proposed. The technique proposed herein is location-based and can be used in conjunction with the existing Location-Aided Routing (LAR) scheme to further reduce the route discovery overhead. A unique feature of our technique not found in LAR and most other protocols is the selective use of unicast instead of broadcast for route request/query transmission made possible by a novel reuse of routing and location information. We refer to this new optimization as the UNIQUE (UNIcast QUEry) technique. This paper studies the efficacy of UNIQUE by applying it to the route discovery of the Dynamic Source Routing (DSR) protocol. In addition, a comparative study is made with a DSR protocol optimized with only LAR. The results show that UNIQUE could further reduce the overall routing overhead by as much as 58% under highly mobile conditions. With less congestion caused by routing traffic, the data packet delivery performance also improves in terms of end-to-end delay and the number of data packets successfully delivered to their destinations.

• Journal of Korea Society of Industrial Information Systems
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• v.10 no.3
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• pp.30-37
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• 2005

Ad hoc network is a collection of mobile nodes without using any infrastructure, it , is using in the various fields. Because ad hoc network is vulnerable to attacks such as routing disruption and resource consumption, it is in need of routing protocol security. In this paper, we propose two secure route-discovery protocols. One is a protocol using hash function. This protocol is weak in active attack but has some merits such as small data of transmission packet and small computation at each hop. The other is a protocol using hash function and public key cryptography. This protocol is strong in active attack.

• Journal of the Korea Computer Industry Society
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• v.2 no.9
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• pp.1219-1224
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• 2001

There can exist unidirectional links due to asymmetric property of mobile terminals or current wireless environments on practical mobile ad hoc networks. However, at present, the existing mobile ad hoc routing protocols are implemented to support only bidirectional links. Thus, in this paper, we extend the existing dynamic source routing protocol in order to implement a new routing protocol, which is fit to mobile ad hoc networks containing unidirectional links. For performance evaluation, we use combinations of mobility scenario files and connection pattern files from Carnegimelon Univ. We consider received data rate and average route discovery time as evaluation items, which are compared and evaluated for three suggested route discovery methods.

• The KIPS Transactions:PartC
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• v.9C no.6
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• pp.935-944
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• 2002

It is the Mobile Ad Hoc Networks that constituted with serveral mobile node that can communicate with other mobile nodes. Until now, there were no routing protocols considering such as Multimediadata, VOD (Video On Demand), which is required of lots of bandwidth in Mobile Ad Hoc Network, io we are in the need of QoS (Quality of Service)routing protocol to transmit the data packets faster and more accurate. Also, there are an unidirectional links due to asymmetric property of mobile terminals or current wireless environments on practical mobile ad hoc networks. However, at present, the existing mobile ad hoc routing protocols are implemented to support only bidirectional links. In this paper, we propose the Advanced Routing routing protocol in order to implement a new routing protocol, which is fit to mobile ad hoc networks containing unidirectional links and to support QoS service. For the performance evaluation, we use NS-2 simulator of U.C. Berkeley. We could get not only increased received data rate and decreased average route discovery time, but also network load decreases with compared Best effort service.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.1389-1392
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• 2005

Ad-Hoc Network 기술은 차세대 네트워크로 부각되고 있으며 IETF (Internet Engineering Task Force) MANET (Mobile Ad-Hoc Network) 워킹그룹에서 표준화 작업이 이루어지고 있다. Ad-Hoc Network 에서 라우팅은 중요한 요소이다. 다양한 서비스를 제공하기 위해서는 잘 정의된 라우팅 기법이 필요하다. 본 논문에서는 기존에 연구되고 있는 Ad-Hoc 라우팅 프로토콜 중 (AODV, PAODV, TORA, DSR, DSDV) 프로토콜들을 NS 시뮬레이터를 이용하여 동작과 성능을 비교 분석하여, Ad-Hoc 라우팅 프로토콜 중 가장 적합한 라우팅 프로토콜을 제시한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9B
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• pp.795-801
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• 2008

Wireless Mesh Networks (WMNs) are popular due to their low cost and rapid deployment. Currently, many WMN researchers often considers the use of ad-hoc routing protocols because WMNs are similar to the ad-hoc networks. Some of currently deployed WMNs consider to use on-demand routing protocols such as Ad-hoc On-demand Distance Vector (AODV) and Dynamic Source Routing (DSR). But, AODV are not appropriate for Wireless Mesh Networks (WMNs), because flooding-based route discovery is both redundant and expensive in terms of control message overhead. In this paper, we propose a directional AODV (D-AODV) routing protocol based on hop count to a gateway. We implement the D-AODV routing protocol and evaluate the performance of the D-AODV on the testbed. The measurement results show that the D-AODV can enhance the network throughput by reducing the routing overhead.