• Journal of IKEEE
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• v.17 no.4
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• pp.484-491
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• 2013

In this paper, we proposed an internal multiband loop embedded monopole antenna for mobile handset that could be used for smart phones. The proposed antenna has a volume of 40 mm(W) ${\times}$ 15 mm(L) ${\times}$ 5 mm(H), ground plane size is 40 mm(W) ${\times}$ 80 mm(L), and covers the GSM900 (Global System for Mobile communications : 880-960 MHz), K-PCS (Korea-Personal Communications Service : 1750-1870 MHz), US-PCS (US Personal Communications Service : 1850-1990 MHz), WCDMA (Wideband Code Division Multiple Access : 1920-2170 MHz), Wibro (2300-2390 MHz), Bluetooth (2400-2483 MHz) and WLAN (Wireless Local Area Network : 2400-2483.5 MHz) bands for VSWR (voltage standing wave ration) less than 3. The proposed loop adding design at middle section of longest branch showed wide impedance bandwidth for the lowest resonance frequency band. The proposed antenna have a lowest resonance frequency band from 738 MHz to 1075 MHz for S11 value of -6dB. A HFSS (High Frequency Structure Simulator) of the Ansys Corporation based on a finite element method is employed to analyze the proposed antenna in the design process and to compare the simulation and experimental results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.5
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• pp.1284-1294
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• 2010

The ZigBee is one of the most important technologies for composing USN. It is one of the IEEE 802.15.4 standards to support personal area networks. It uses a hierarchical routing or an on-demand route discovery strategy as an address allocation method. A hierarchical routing doesn't use a routing table but only uses a child node or a parent node as an intermediate node for data delivery. Therefore, the ZigBee network's topology greatly affects the overall network performance. In this paper, we propose a more trustworthy algorithm than only using the depth and widely variable LQI during network formation, and moreover we propose an algorithm to measure network's trustworthiness. We simulate our algorithm using the NS-2 and implement our network using the MG2400 ZigBee module for verifying performance.

• Journal of Legislation Research
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• no.53
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• pp.177-211
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• 2017

In the course of the emergence and development of new ICT technologies and services such as Big Data, Internet of Things and Artificial Intelligence, the future will change by these new innovations in the Fourth Industrial Revolution. The future of this fourth industrial revolution will change and our future will be data-based society or economy. Since there is personal information at the center of it, the development of the economy through the utilization of personal information will depend on how to make the personal information protection laws. In Korea, which is trying to lead the 4th industrial revolution, it is a legal interest that can not give up the use of personal information, and also it is an important legal benefit that can not give up the personal interests of individuals who want to protect from personal information. Therefore, it is necessary to change the law on personal information protection in a rational way to harmonize the two. In this regard, this article discusses the problems of duplication and incompatibility of the personal information protection law, the scope of application of the personal information protection law and the uncertainty of the judgment standard, the lack of flexibility responding to the demand for the use of reasonable personal information, And there is a problem of reverse discrimination against domestic area compared to the regulated blind spot in foreign countries. In order to solve these problems and to improve the legislation of personal information protection in the era of the fourth industrial revolution, we proposed to consider both personal information protection and safe use by improving the purpose and regulation direction of the personal information protection law. The balance and harmony between the systematical maintenance of the personal information protection legislation and laws and regulations were also set as important directions. It is pointed out that the establishment of rational judgment criteria and the legislative review to clarify it are necessary for the constantly controversial personal information definition regulation and the method of allowing anonymization information as the intermediate domain. In addition to the legislative review for the legitimate and non-invasive use of personal information, there is a need to improve the collective consent system for collecting personal information to differentiate the subject and to improve the legislation to ensure the effectiveness of the regulation on the movement of personal information between countries. In addition to the issues discussed in this article, there may be a number of challenges, but overall, the protection and use of personal information should be harmonized while maintaining the direction indicated above.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.6B
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• pp.350-357
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• 2007

The IEEE 802.15.3 high-rate WPAN has been developed to communicate with devices within l0m. A piconet consists of one Piconet Coordinator (PNC) and several devices. The devices associated with a parent piconet can become child PNCs in order to form child piconets. A mesh network made up of a parent piconet and several child piconets can support multi-hop communications. In this paper, we analyze the maximum level and the avaliable superframe size to make the best use of bandwidth for multi-hop communications, and compare the analysis with the simulation results in terms of time to discover devices for multi-hop communications. The average number of levels in mesh networks is shown to be about 1.9 when the number of devices increases within a fixed area. We have also shown that the maximum available superframe size is 52ms and the discovery time is approximately 155ms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.11
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• pp.1216-1223
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• 2014

Internet traffic is rapidly increasing due to the spread of personal smart devices and the demand for multimedia contents. When designing a large ship such as cruise, network architecture is also considered which supports various IT services in a maritime environment similar to the ground environment. In this paper, we consider wireless P2P (peer-to-peer) communication for efficient multimedia content sharing and propose novel handover scheme for efficient download service. The proposed handover method shows that it can improve the download symbol rates for handover in a wireless P2P system considering the signal strength and quality of peers as well. The proposed system is expected to provide efficient contents distribution and reliable communication in the ship-area-network (SAN).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.1
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• pp.43-56
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• 2013

Personal Rapid Transit(PRT), which is one of the next generation convergence transport technology, PRT system requires operation technology for controlling diverse vehicles and dealing with a variety of abnormal driving situations on a large scale trackway structures in expected operational area more efficiently and reliably. Before developing PRT control technology, it is essential that multiple testing procedures stepwise with building small scale test-tracks and develop real unmanned-vehicles. However, it is expected that the experiments demand huge amount of time and physical cost. Thus, simulation in virtual environment is efficient to develop wireless based control technology for multiple PRT vehicles prior to building real-test environment. In this paper, we propose a VR-based integrated simulator which physics engine is applied so that it enables simulation of front-wheel-steering PRT system rather than simple rail track system. The proposed simulator is also developed that it can reflect geographical features, infrastructures and network topology of expected driving region.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.8 s.350
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• pp.25-34
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• 2006

In this paper DynaMoNET is suggested as a novel IPv6-based multi-homed mobile network architecture which is composed of nested mobile ad hoc networks dynamically coming together through wireless personal area networks. Each ad hoc network has a mobile router which may work as a root mobile router instead of fixed mobile routers in a DynaMoNET. A root mobile router provides the reliable Internet connectivity for the entire mobile network. This paper includes a innovative handover protocol for multi-homed mobile networks, network switchover algorithm considering multiple decision factors, root mobile router election process based on token-based algorithm fast root mobile router discovery algorithm and fault avoidance mechanism to support reliable Internet connectivity. Finally the system architecture of a mobile router is given in detail.

• The Journal of Society for e-Business Studies
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• v.13 no.2
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• pp.195-212
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• 2008

The demand of wireless communication system is increasing due to the development of computers and other digital media appliances. In particular, new wireless communication technology is necessary for implementation of home network since a lot of data transmission is occurred. Recently, two wireless communication technologies, Ultra Wide Band(UWB) and 60GHz band wireless communication technology, have being developed for high-speed data transmission and Wireless Personal Area Network(WPAN). In this paper, we study the present development condition of these two technologies and a role of them in home network. We also suggest the method to implement the home network using all wireless communication technologies. At the end, we outlook the market of WPAN and High Definition Multimedia Interface(HDMI).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.1
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• pp.206-215
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• 2007

Ad-Hoc network technology is a mobile internet technology of the future that will be used widely not only in Mobile Network but also in Wireless Personal Area Network (WPAN) and Ubiquitous Network For this to occur, distributed routing protocol design, loop prevention for link information reduction in overhead for control messages and route restoration algorithm must be improved or complemented. Security techniques that can guarantee safe com-munication between Ad-Hot nodes net also be provided. This study proposes and evaluates a new authentication mechanism for MANET. The mechanism segregates the roles of certification authority to keep with the dynamic mobility of nodes and handle rapid and random topological changes with minimal over-head. That is, this model is characterized by its high expandability that allows the network to perform authentication service without the influence of joining and leaving nodes. The efficiency and security of this concept was evaluated through simulation.

• The Journal of the Korea Contents Association
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• v.9 no.7
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• pp.76-85
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• 2009

UWB signal with high resolution capability can be used to estimate ranging and positioning in wireless personal area network. The node works on its local clock and the frequency differences of nodes have serious affects on ranging algorithms estimating locations of mobile nodes. The low rate UWB, IEEE802.15.4a, describes asynchronous two way ranging methods such as TWR and SDS-TWR working without any additional network synchronization, but the algorithms can not eliminate the effect of clock frequency differences. Therefore, the mechanisms to characterize the crystal difference is essential in typical UWB PHY implementations. In high rate UWB, characterizing of crystal offset with tracking loop is not required. But, detection of the clock frequency offset between the local clock and remote clock can be performed if there is little noise induced jitter. In this paper, we complete related ranging equations of high rate UWB based on TWR with relative frequency offset, and analyze a residual error in the ideal equations. We also evaluate the performance of the relative frequency offset algorithm by simulation and analyze the ranging errors according to the number of TWR to compensate coarse clock resolution. The results show that the relative frequency offset compensation and many times of TWR enhance the performance to converge to a limited ranging errors even with coarse clock resolutions.