• The Journal of the Korea Contents Association
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• v.11 no.7
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• pp.70-79
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• 2011

The multi-path routing schemes that assigns labels to sensor nodes for the reliability of data transmission and the accuracy of an aggregation query over the sensor networks where data transfer is prone to defect have been proposed. However, the existing schemes have high costs for reassigning labels to nodes when the network topology is changed. In this paper, we propose a novel routing method that avoids duplicated data and reduces the update cost of a sensor node. In order to show the superiority of the proposed scheme, we compare it with the existing scheme through the various experiments. Our experimental results show that our proposed method reduces about 95% the amount of the transmitted data for restoration to node failure and about 220% the amount of the transmitted data for query processing over the existing method on average.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.1
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• pp.53-59
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• 2009

As a special type of Wireless Ad Hoc Networks, Wireless Mesh Networks (WMNs) have become the comer stone of research issues. Due to the limited operational environment of WMNs, an efficient connected dominating set (CDS) construction scheme is an important concern since it has been found extremely useful in broadcasting, routing and virtual backbone construction. In this paper, we propose a distributed Bandwidth-Interference aware CDS construction scheme to improve the network performance via two parameters such as node's number of neighbor and link bandwidth. Our CDS construction scheme selects the node that has more neighbors and enough bandwidth to support more end-devices in order to enhance overall network throughput and reliability. We confirm through simulations and show that our scheme constructs the CDS with the small subset of DS and the link that has better bandwidth.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.11A
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• pp.1034-1042
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• 2008

It is very hard, but important to sustain path stability for a reliable communication in mobile ad hoc networks. We propose a novel source routing protocol that establishes a group path with virtual multiple paths to enable a robust communication. The entire mobile nodes form a disjoint set of clusters: Each has its clusterhead as a cluster leader and a unique cluster label to identify itself from other clusters. A group path is a sequence of cluster labels instead of nodes and the nodes with the same label collaborate to deliver packets to a node with next label on the group path. We prove by resorting to simulation that our proposed protocol outperforms the existing key routing protocols, even for a network with a high node mobility and a high traffic.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.99-114
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• 2012

Proxy Mobile IPv6 (PMIPv6) has received considerable attention between telecommunications and the Internet communities and does not require active participation of the Mobile Node (MN) by way of network-based mobility management. The PMIPv6 domain is studying establishment in progress to support extensively a number of MN by using a low handover latency. In this research, we are propose a novel 3S scheme for building Scalable and Secure and Seamless PMIPv6 domains. In the proposed scheme, all of Mobility Access Gateway (MAG) are acting as the Local Mobility Anchor (LMA) and composing a virtual ring with another MAG. General hashing is used in the efficient distribution-mapping between each MN and the MN's LMA of all MAGs. And, MAG and MN are authenticated using the symmetric key. Through mathematical analysis, we verifies the safety, scalability, and seamless service for 3S. Also, we're propose a handover procedure of 3S and show better than the existing schemes in terms of handover latency.

• Smart Media Journal
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• v.9 no.3
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• pp.71-79
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• 2020

Mobile network is used by many users worldwide for diverse services, including phone-call, messaging and data transfer over the Internet. However, this network may experience massive damage if it is exposed to cyber-attacks or denial-of-service attacks via wireless communication interference. Because the mobile network is also used as an emergency network in cases of disaster, evaluation or verification for security and safety is necessary as an important nation-wide asset. However, it is not easy to analyze the mobile core network because it's built and serviced by private service providers, exclusively operated, and there is even no separate network for testing. Thus, in this paper, a virtual mobile network is built using OpenAirInterface, which is implemented based on 3GPP standards and provided as an open source software, and the structure and protocols of the core network are analyzed. In particular, the S1AP protocol messages captured on S1-MME, the interface between the base station eNodeB and the mobility manager MME, are analyzed to identify potential security threats by evaluating the effect of the messages sent from the user terminal UE to the mobile core network.

• Journal of KIISE:Information Networking
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• v.29 no.3
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• pp.314-323
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• 2002

The routing protocols designed for wired networks can hardly be used for mobile ad-hoc networks due to limited bandwidth of wireless transmission and unpredictable topological change. Recently, several routing protocols for mobile ad-hoc networks have been Proposed. However, when theme protocols are applied to support real time services like multimedia transmission, they still have problems in ad-hoc networks, where the topology changes drastically. In this paper, we propose a new route selection algorithm which selects the most reliable route that is impervious to route failures by topological changes by mobile hoots. For reliable route selection, the concept of virtual zone (stable zone and caution zone) is proposed. The zone is located in a mobile node'transmission range and determined by mobile node's mobility information received by Global Positioning System (GPS). The proposed algorithm is applied to the route discovery procedure of the existing on-demand routing protocol, AODV, and evaluated by simulation in various traffic conditions and mobility patterns.

• Journal of KIISE:Information Networking
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• v.29 no.3
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• pp.224-232
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• 2002

The routing protocols designed for wired networks can hardly be used for mobile ad-hoc networks due to limited bandwidth of wireless transmission and unpredictable topological change. Recently, several routing protocols for mobile ad-hoc networks have been proposed. However, when these protocols are applied to support real time services like multimedia transmission, they still have problems in ad-hoe networks, where the topology changes drastically. In this paper, we propose a new route selection algorithm which selects the most reliable rouse that is impervious to route failures by topological changes by mobile hosts. For reliable route selection, the concept of virtual zone (stable lone and caution zone) is proposed. The lone is located in a mobile node's transmission range and determined by mobile node's mobility information received by Global Positioning System (GPS). The proposed algorithm is applied to the route discovery procedure of the existing on-demand routing protocol, AODV, and evaluated by simulation in various traffic conditions and mobility patterns.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.12B
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• pp.1199-1210
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• 2010

In recent years opportunistic computing has gained popularity in Ad-hoc network research area and it is highly required to research for actual services and related requirements. In this paper we summarized a virtual opportunistic service that is named "Children Care System" and proposed an Ad-hoc communication node (uMobile) that is connected with cellular phone and a sensor node (uClo) which is embedding into clothes. uMobile can support cellular phone communication and Ad-hoc communication and uClo can be embedded into clothes and recognize the user status using multiple sensors. In this paper we implemented the location awareness and user status awareness services using uMobile and uClo. We also tested them in indoor situation and showed the result. We expect that our research can play a significant role to inspire another various opportunistic computing services.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9A
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• pp.1431-1440
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• 2000

In order to support efficiently the multimedia applications, such as virtual classroom, video conferencing and tele-medical, the efficient multipoint-to-multipoint(MP-to-MP) connection management function is essential. Shared tree is reported as the most useful method for this purpose. In this paper we propose a new MP-to-MP connection setup & management scheme, called CIMA(Cell Interleaved Multiplexing on ATM) scheme,which is a VC merging method for MP-to-MP communication using shared tree. In the CIMA scheme,MRM cell delivers the cell merging information to the next node. The receiving node can identfy cells which arrived through a channel using the same VPI/VCI by the merging information in the MRM cell. Therefore the CIMA scheme can solve easily the Cell Interleaving Problem(CIP) that happens in VC merging. We analyzed the overhead of the proposed CIMA by mathematical analysis,and simulated the buffer usage of CIMA with OPNET. As the result of analysis,we found that the CIMA scheme has acceptable merging overhead and doesn't cause the buffer scare problem.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.11 no.3
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• pp.3-12
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• 2001

In this course of Internet proliferation, many network-related technologies are examined for possible growth and evolution. The use of Internet-based technologies is private networks has further fuelled the demand for network-based applications. The most promising among the new paradigms is the use of mobile agents. The mobile agent is capable of migrating autonomously form node to node in the network, to perform some computations on behalf of the user. The mobile agent paradigm is attractive alternative to traditional client-server programming for a significant class of network-centric applications. It does however, suffer. from a major drawback namely, the potential for malicious attacks, abuse of resources, pilfering of information, and other security issues. These issues are significantly hampering the acceptance of the mobile-agent paradigm. This paper describes the design of a secure mobile agent gateway 7hat can split and merge the agent code with security policy database on the VPN. This mechanism will promote security in the mobile agent systems.