• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.476-479
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• 2003

Recently, Bluetooth has been regarded as a new technology for short-range wireless connection. Although initial application of Bluetooth technology has been focused mainly on replacing cables between hand-held devices due to a limited packet size and short-range, general wireless telecommunication such as PAN and Ad hoc networks via Bluetooth-equipped devices is expected to be one of the most popular applications. Wireless equipments have been used to exchange data between host and mobile unit. The exchanging data may be several bytes of control command and the value of sensors with ultra-sonic, vision sensor, and encoder from mobile robot. However, most wireless equipments have some drawbacks such as lack of authentication, large size and high price. On the other hand, the benefits of Bluetooth are small size, low power, low price except short-range. Especially, there are some difficulties when wireless modules are used in indoor environments. In this paper, a method of using wire network in Bluetooth network is investigated as a solution to overcome the short-range problem of Bluetooth and difficulty in indoor environment.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.224-230
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• 2010

Wireless power transmission (WPT) is useful technology in near future. There are some kinds of the WPT technologies, WPT via radio waves, resonance coupling, and inductive. Especially the WPT via radio waves is used for multi-purposes from short range to long range application. However, unfortunately it is misunderstood that it is low efficiency and low power. In this paper, I show the theory of beam efficiency between transmitting antennas and receiving antennas and also show some high efficient applications of the WPT via radio waves. Especially, I pick up a wireless power charging system of an electric vehicle and show the experimental results. I show difference between the theory of beam efficiency and the experimental results of short range WPT. I indicate that reasons of poor beam efficiency in the experiment are (1) change of impedance caused by mutual coupling between transmitting antennas and receiving antennas, (2) oblique direction of microwave power to receiving antennas caused by short distance.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.4
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• pp.632-638
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• 2012

ZigBee network, based on PHY, MAC layer provides a specification for a suite of high level communication protocols using small, low-power digital radio based on an IEEE 802.15.4 standard. Meshing is a type of daisy chaining from one device to another. This technique allows the short range of an individual node to be expanded and multiplied, covering a much larger area. Each wireless technology that makes it to market serves a special purpose or function. Zigbee provides short-range connectivity in what is called a personal-area network (PAN). Within ZigBee PAN coordinator as manages an entire ZigBee network, the short range of frequency band was only selected because the technology allows typically less than 100 kbp or ZigBee troubles in retransmission processing and delaying data tranmission works to create unproductive condition of work. This research was proposed the method, based on short range frequency of zigBee nodes enable to long range of remote data transmission with specific algorithm tools.

• Electronics and Telecommunications Trends
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• v.34 no.6
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• pp.61-70
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• 2019

Recently, research and development for next-generation mobile communication and short-range wireless communication has begun worldwide along with the provision of commercial services of 5G mobile communication technology. In response to this trend, the THz band has attracted considerable attention as a frequency band for transmitting 100 Gbps of large-capacity wireless data. For communication in the THz band, research and development of approaches based on photonics and electronics is being actively performed; the configurations, characteristics, and performances of these two methods for THz transmission have been seriously examined. Among them, we reviewed the technical issues in implementing THz wireless transmission technology using photonics technology. We also introduced the Electronic and Telecommunications Research Institute's (ETRI) development of photonics-based THz short-range transmission technology starting from 2019 and including some initial results. In the near future, 100 Gbps high-capacity wireless data transmission technology utilizing photonics technology is expected to be commercially available and applied to various applications, such as 3D hologram transmission, uncompressed large capacity medical data transmission, and multiple augmented reality/virtual reality (AR/VR).

• Journal of Korea Multimedia Society
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• v.20 no.9
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• pp.1519-1526
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• 2017

The existing DSRC(Dedicated Short Range Communication) scheme has a limitation in providing various services through short-range wireless communication. Therefore, it is necessary to develop an intelligent WAVE/DSRC hybrid wireless platform that can improve data transmission speed and extend the effective communication range. This paper introduces WAVE/DSRC integrated platform technology using WAVE(Wireless Access in Vehicle Environments) to overcome the disadvantages of DSRC. First, the desinged software configuration of the WAVE/DSRC integrated platform is described. Then each task operation scheme and WAVE software design are described. By applying the WAVE/DSRC integrated platform, we can compensate the shortcomings of DSRC. It can provide more accurate and reliable services.

• Journal of IKEEE
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• v.22 no.1
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• pp.216-222
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• 2018

Long-range wireless power transmission technology goes beyond mere cell phones and small appliances, and is the core technology of 4'th industrial revolution such as robot, electric car, and IoT sensor network. In this paper, we will explore the evolution of long-range wireless power transmission technologies that have already become commercially available, with rapid advances in technology, beyond the traditional short-range technology that has become technologically common. Through this, it is intended to check the domestic research level and progress by identifying core technologies and technical challenge.

• Journal of Digital Contents Society
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• v.7 no.3
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• pp.139-145
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• 2006

Short-range wireless transmission and networking technologies are becoming increasingly important in enabling useful mobile applications. Bluetooth and IEEE 802.11b standards are the most commonly deployed technologies for WPAN and WLAN. This paper investigates the effect of short range wireless channel on the performance of MC-CDMA/BPSK system and Bluetooth GFSK signal transmission in AWGN and Rician fading environments. And we investigate performance degradation due to interference effects in short range wireless channel. We firstly derive a equation for the bit error probability in additive white Gaussian noise depending on MC-CDMA/BPSK signal and GFSK modulation signal parameters according to the Bluetooth RF standard. Then, from this error rate expression we calculate the mean error probability for MC-CDMA/BPSK signal and Bluetooth GFSK signal in Rician fading and interference channel. In particular, the impacts of the Rician fading depth and interference level on the error probability is shown in BER performance figures.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.437-442
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• 2005

This paper deals with the measurement and analysis of radio characteristic of 424 MHz for using the automation of transmission and supply of electric power, ana automatic meter reading(AMR). Normally radio propagation characteristic is the base of system design, performance evaluation and choice of position of the base station in wireless communication. It is the most accurate way to design a base station through practical measurements, but it costs much time, money and engineers. So, we developed 424 MHz short range wave propagation model for AMR service.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.534-535
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• 2012

The characteristics of wireless power transfer is achieved at high frequencies in short range magnetic resonant wireless power transfer system. Use PFC pre-regulator for power supply of high frequency inverter. Supplied power to high power factor and high efficiency. Accordingly, the input voltage is 110V-220V. The designed of 175W Class with the output voltage of 385V. As a experiment result, maximum power factor and maximum efficiency measured 99% and 97% respectively. Therefore, in this paper, the design of a inductor which is the most important element in PFC converter for short range magnetic resonance wireless power transfer system was studied. Used an CS330125 core through the designed of 175W class. Examination results power loss was 0.2%.

• IEMEK Journal of Embedded Systems and Applications
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• v.1 no.2
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• pp.82-89
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• 2006

It appears that it is possible for us to make a wireless communication of even home-network system within car by integrating with the Ubiquitous such as mobile phone, wireless Internet, GPS and DMB in the future. If the present wireless surroundings within the car are connected with very high-speed wireless network as measurement system for wireless communication surroundings within this car in the future, it will develop the complicated communication conditions such as safe checkup, communication between systems within car, and wireless communication for user entertainment unlike universal communication conditions. Accordingly, there is the necessity of the device that can measure the interference of electric wave, communication speed and communication quality by a kind of each car. This paper aims at making the real measurement device to raise the reliability of each Application for inquiring into the interference about each other in the frequency band used under Telematics surroundings.