• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.754-762
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• 2021

Seamless wireless communication network access technology enables users to guarantee service continuity. Hence, it is necessary for disaster situations in which network service may be interrupted. The Multi-path router is a technology to improve network stability and strengthen field operability, particularly in a disaster environment where network failure can occur by providing high-performance data transmission using multi-communication networks and network security by VPN-based wireless IP. In this paper, a prototype system for an MPR-based wireless communication network was proposed to improve the operation performance for disaster field investigation applications. A comparative experiment was performed on various data transmission performances with the existing single wireless communication network. In addition, another experiment was conducted by measuring the data packet transmission and receiving performance in the existing/new wireless communication system first and then assessing the UDP transmission performance in a single router environment to understand the transmission capability of the new MPR. The experimental results showed that the sending and receiving performance was improved by approximately double that of the existing single wireless communication system. The proposed prototype system is expected to allow users to share and disseminate collected on-site data more quickly and efficiently during a disaster site investigation.

• Journal of Korea Multimedia Society
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• v.7 no.5
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• pp.680-688
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• 2004

In this paper, we propose a new handoff scheme which is efficient in hybrid mobile data network consists of cellular mobile network and wireless LAN. In this scheme, handoff is delayed until connections with wireless LAN and data rates are smoothly decreased according to becon signal strength of wireless LAN. By doing so, data transfer capacity is increased and required data buffer in handoff for mobile and network system can be decreased. We analyze new handoff scheme by computer simulation. The results show that 180Mbytes data can be transferred additionally in handoff processing and required buffer size can be decreased 1/2 with the conditions that mobile speed is 1Km/hr and the data rate of a original call is 2,048Kbps.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.7B
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• pp.668-676
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• 2009

Hierarchical Mobile 1Pv6(HM1Pv6) have been proposed by IETF(Internet Engineering Task Force) beginning from Mobile 1Pv6 for mobility support in IP networks, however these researches relying on client based mobility support have not been drawn attention due to excessive consumption of wireless resources and long handover delay. In this paper, we propose the Router-based Binding Update(RBU) scheme to solve problems in existing client-based mobility support schemes. The router registers location information of mobile nodes through Neighbor Discovery protocol without additional codes for the RBU scheme to a terminal operated by existing HMlPv6. By using this the RBU scheme is designed so that it can support partial nupport based mobility and reduce handover latency rather than using HMIPv6. It is analysed and compared with existing HMIPv6 to verify efficiency of the RBU scheme. As a result, the RBU scheme has outperformed existing HMIPv6 by 15% in terms of macro handover delay especially when long delay on wireless links exists.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.5
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• pp.123-129
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• 2014

This paper suggests that it provides a electricity management system for wasting electricity, from power demand growth environments. This Energy management system based on ICT(Information & Communication Technology) can control Smart Power Outlet connecting to this system with Web Browser and Android phone, anytime, anywhere. Through analysis of acquisition data from them, this proposed system can monitor and control power consumption efficiently. This system was organized mesh network of Smart Power Outlet, gateway by wireless Zigbee, and ESS(Energy Saving System) by TCP/IP beyond existing limit of communication distance and space.

• Journal of Satellite, Information and Communications
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• v.7 no.3
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• pp.130-134
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• 2012

This paper introduces a home network service system using a low-cost wireless router on OpenWrt which can be remotely controled by Android devices. The proposed system consists of an embedded system development platform for home network service control based on OpemWrt embedded Linux, an embedded system development platform, a remote control on Android, and a home linghting device made by an interface board with LEDs. The prototype system is made of a wireless router of Buffalo, WZR-HP-G450H, Arduino Uno interface board with LEDs, and an Android development kit of HBE-SM5-S421. The operation was performed by TCP/IP programming for Android remote control, socket programming between Android development kit and wireless router, and UART communication programming between the interface board and wireless router. The implementation result shows that a low cost home network systme could be implemented with a wireless router.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.2
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• pp.254-259
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• 2008

Mesh WLANs, which consist of wireless mesh routers connecting each other in a mesh topology and self-operate after their autoconfiguration, have several advantages in convenience, swiftness and flexibility of deployment and operation over existing WLANs the expansions of which are done by connecting the APs with wires. However, many technical issues still remain to be solved. Among them, network performance degradations due to the interference between the adjacent hops in multi-hop mesh WLANs, and the reusability of the existing wireless network protocols are critical problems to be answered. This work evaluates the VoIP support performance of IEEE 802.11a/g-based mesh WLANs with multiple wireless interfaces with simulations. The results show that there exit an unfairness in VoIP packet delay performances among mobile routers located at different hops, and that although the capacity of the admitted calls can be increased by increasing the size of voice packet payload it is far less than the expected one. This suggests that the existing 802.11 MAC protocols have their limitation when applied in mesh networks and their enhancement or even a newer one nay be required.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.1
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• pp.46-63
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• 2012

The concept of an "intelligent building" received significant attention from academic, industry and standard development organizations when technically termed a building management system (BMS). Wireless sensor networks (WSNs) and their recent development enhanced monitoring and control applications for the building's areas. This paper surveys and analyzes advantages of the main current and emerging approaches that may be fit for BMS. Specifically, we discuss challenges including interoperability, integration, overhead, and bandwidth limitation of WSNs in BMS. Based on analyses, we highlight the advantages of an IP-based and RESTful architecture approach as the most suitable solution for BMS using WSNs (BMS-WSN). The paper also describes our future direction and design for BMS-WSN based on these advantages. The purpose is to enable interaction of users with BMS-WSN in the same way as with any website while ensuring energy efficiency. A test-bed implementation and evaluation of a BMS application is also introduced in this paper to demonstrate the feasibility and benefits of IP-based and RESTful architecture for BMS.

• Journal of KIISE:Information Networking
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• v.28 no.3
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• pp.321-335
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• 2001

The explosive growth in wireless networking increasingly urges the demand to support mobility within the Internet which is what Mobile-IP aims to provide. Because the transmission of signals through open-air s easy to be attacked, it is important to provide secure transmission for mobile users and make them responsible for what they have done in networks. Although IETF provides a secret-key based security mechanism, those mechanisms suffer from scalability, efficiency and non-repudiation service problem. The proposed mechanism uses public-key based authentication optimizing the performance. It includes non-repudiation service on the side of mobile for airtight security in wireless network. The simulation results show that the proposed authentication reduces the total registration time. It especially minimizes the computation cost on the side of the mobile node and solves the power problem. In practice, the proposed authentication is feasible with reasonable performance and security service in macro mobility that Mobile-IP is intended to solve.

• Journal of Digital Contents Society
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• v.11 no.4
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• pp.433-443
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• 2010

In this paper, we provide a comprehensive overview and classification on a wide range of the existing location management schemes which have been reported for wireless cellular networks and Mobile IP-based networks, respectively. In addition, from the various previous literature, we derive common key conceptual techniques, their main design goals and performance considerations on them, which can provide a useful guidance for understanding location management schemes regardless of network types. The aim of this paper is not to propose a new scheme for location management, but to highlight the various key design features involved in the design of the existing location management schemes, and to enhance an insight into the fundamental principles and techniques for designing more efficient and optimized location management scheme in future wireless mobile networks. We expect that regardless of network types, these underlying fundamental principles and conceptual techniques could be also easily tailored for more efficient mobility/QoS support in future mobile computing environments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.750-752
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• 2010

MANET has some interest as a wireless mobile network supporting node mobility and having no additional infrastructure. Speed of mobile node on MANET is various from just slow speed of human's walk to vehicle's moving speed. In this study, VoIP performance of MANET is evaluated in the view of speed of mobile node. VoIP performance is studied on walking speed, vehicle speed and higher speed on MANET. PDR(Packet Delivery Ratio), MOS(Mean Opinion Score) are used as performance parameters.