• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.103-109
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• 2013

Mobile ad hoc networks (MANETs) are infrastructure-less and stand-alone wireless networks with dynamic topologies. To support user's safety in MANETs, fundamental and various security services should be supported. Especially in mobile commercial market, one of the major concerns regarding security is user privacy. Recently, researches about security system to protect user privacy in cluster-based MANETs have been introduced. This paper propose a cluster reconfiguration protocol under anonymous cluster-based MANETs to enhance the network stability. The improved anonymous cluster-based MANETs can recover the network structure against abnormal states of clutserheads.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.173-179
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• 2008

An ad hoc network is multi-hop wireledss formed by mobile node without infrastructure. Due to the mobility of nodes in mobile ad hoc networks, the topology of network changes frequently. In this environments, multicast protocols are faced with the challenge of producing multi-hop routes and limitation of bandwidth. We compare the performance of two multicast routing protocols for mobile ad hoc networks - Serial Multiple Disjoint Tree Multicast Routing Protocol (Serial MDTMR) and Adaptive Core Multicast Routing Protocol (ACMRP). The simulator is implemented with GloMoSim.

• Journal of KIISE:Information Networking
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• v.34 no.6
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• pp.475-482
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• 2007

Mobile nodes in ad-hoc wireless networks play roles of router as well as host. Movement of nodes causes network topology changes, which make existing routing information be modified. Therefore many routing protocols for ad-hoc networks were suggested in the literature. In this paper, we suggest an enhanced automatic route shortening method for dynamic source routing(DSR) protocol. DSR is a request/response based protocol which has low routing overhead owing to node movement. The current automatic route shortening is performed on the only nodes which belong to the source route of packets. On the contrary, our suggested method allows all neighbor nodes hearing the packet to participate in automatic route shortening. It makes all possible route shortenings be performed. So we maintain maximal shortened routes of ongoing data connections. Simulation results with ns2 show that our method pays small extra protocol overhead for ARS, but increases the ratio of successful packet transmissions and the number of ARSs performed in our mechanism is from 2 to 5 times higher than in original ARS mechanism and therefore it will improve the network-wide energy consumption in wireless ad-hoc networks.

• The KIPS Transactions:PartC
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• v.12C no.5 s.101
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• pp.623-632
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• 2005

In ad-hoc network, there is no fixed infrastructure such as base stations or mobile switching centers. The security of ad-hoc network is more vulnerable than traditional networks because of the basic characteristics of ad-hoc network, and current muting protocols for ad-hoc networks allow many different types of attacks by malicious nodes. Malicious nodes can disrupt the correct functioning of a routing protocol by modifying routing information, by fabricating false routing information and by impersonating other nodes. We propose a routing suity mechanism based on one-time digital signature. In our proposal, we use one-time digital signatures based on one-way hash functions in order to limit or prevent attacks of malicious nodes. For the purpose of generating and keeping a large number of public key sets, we derive multiple sets of the keys from hash chains by repeated hashing of the public key elements in the first set. After that, each node publishes its own public keys, broadcasts routing message including one-time digital signature during route discovery and route setup. This mechanism provides authentication and message integrity and prevents attacks from malicious nodes. Simulation results indicate that our mechanism increases the routing overhead in a highly mobile environment, but provides great security in the route discovery process and increases the network efficiency.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.6
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• pp.33-44
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• 2008

Multipath routing protocols with load balance, fault tolerance, aggregated bandwidth in Ad-hoc Networks provide improved throughput and reliable route as compared with singlepath routing protocols. However, multipath routing protocols have not been explored thoroughly in the domain of overhead in Ad-hoc Networks. In this paper, we analyze and compare on-demand singlepath and multipath routing with IEEE 802.11 DCF in terms of Routing overhead and MAC overhead. The results reveals that in comparison with singlepath routing protocol, multipath routing mechanism creates more overheads but provides better performance in congestion and capacity provided that the route length is within a certain upper bound which is derivable. The analytical results are further confirmed by simulation.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.2
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• pp.14-20
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• 2011

In mobile ad hoc networks where the communication nodes are moving around, one may perform dynamic routing that can increase the total communication throughput of the network, by determining the ranks of pairs of nodes according to their communication throughput. The balanced Howell rotation is a tournament design scheme for bridge games. This paper explains that the balanced Howell rotation can be applied to enhance the overall communication throughput of mobile ad hoc networks, and proposes and proves the condition under which the balanced Howell rotations may exist.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.117-120
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• 2002

Bluetooth uses baseband of 2.4G ISM and composes radio Ad Hoc network based on Ad Hoc wireless connectivity which it used low power and low complexity solution. Bluetooth designed as can play detect, connect, discover service by surrounding other device even if users do not get acquainted all to Bluetooth. This paper operate wish to recognize mobility to routing algorithm how communication method and radio network in Bluetooth.

• Journal of Industrial Technology
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• v.26 no.B
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• pp.183-189
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• 2006

Ad hoc network does not need any preexisting network infrastructure, and it has been developed as temporal networks in the various fields. Infostation is an efficient system to transfer informations which are not sensitive to delay. In this paper, we propose a disaster emergency management system using sensors attached to animals, that is combined with infostation system. We also analyze the performance of the proposed system by simulation. From the performance analysis results, we expect that the proposed system will be very useful to early detect big forest fires which occur frequently in Korea mountain areas.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.6
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• pp.29-34
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• 2008

In this paper, we propose an entropy-based dynamic routing protocol for supporting effective route stability in mobile ad-hoc wireless sensor networks(MAWSN). The basic ideas and features are as follows. First, construction of entropy-based stable routing route using mobility of nodes between a source node and a destination node. Second, usage of location and direction information for route construction to support resource saving. Third, We consider a realistic approach, in the points of view of the MAWSN, based on mobile sensor nodes as well as fixed sensor nodes in sensor fields while the conventional research for sensor networks focus on mainly fixed sensor nodes. The performance evaluation of the proposed routing protocol is performed via simulation using OPNET. The simulation results show the proposed routing protocol can effectively support route stability and packet delivery ratio.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.11
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• pp.27-34
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• 2005

Mobile Ad Hoc Networks (MANETs) are self-organized networks that do not rely in their operation on wired infrastructure. As in any networking technology, security is an essential element in MANET as well, for proliferation of this type of networks. But supporting secure communication in MANETs proved to be a significant challenge, mainly due to the fact that the set of nodes in the network can change frequently and rapidly and due to the lack of access to the wired infrastructure. In particular, the trust model and the authentication protocols, which were developed for wired and infrastructure-based networks, cannot be used in MANETs. In this paper, we address the problem of efficient authentication of distributed mobile users in geographically large networks. In particular, we propose a new authentication scheme for this case of MANETs. The proposed scheme exploits Randomized Groups to efficiently share authentication information among nodes that together implement the function of a distributive Certification Authority (CA). We then evaluate the performance of authentication using Randomized Groups.