• 정보와 통신
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• 제19권7호
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• pp.56-71
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• 2002

Third generation mobile radio systems (3G) are currently being deployed in different regions of the world. Future systems beyond 3G are already under discussion in international bodies and forums such as ITU, WWRF and R&D programs of the European Union and in other regions. These systems will determine the research and standardization activities in mobile and wireless communication in the next years. Based on the experience of 3G future systems will be developed mainly from the user perspective with respect to potential services and applications including traffic demands. Therefore, the Wireless World Research Forum (WWRF) was launched in 2001 as a global and open initiative of manufacturers, network operators, SMEs, R&D centers and the academic domain. WWRF is focused on the vision of such systems the Wireless World - and potential key technologies. This paper describes the international context of activities on systems beyond third generation, the goals, objectives and structure of WWRF, the user perspective as the starting point for a future system design and the key enabling technologies for the Wireless World.

• ETRI Journal
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• 제26권5호
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• pp.405-412
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• 2004

MC-CDMA, a multicarrier (MC) modulation scheme based on code division multiple access (CDMA), is the most likely candidate for the next generation of mobile radio communications. The rate compatible punctured turbo (RCPT) coded hybrid automatic repeat request (HARQ) has been found to give improved throughput performance in a direct sequence (DS) CDMA system. However, the extent to which the RCPT HARQ improves the throughput performance of an MC-CDMA system has not been fully understood. In this paper, we apply the RCPT HARQ to MC-CDMA and evaluate by computer simulations its performance in a frequency selective Rayleigh fading channel. We found that the performance of RCPT HARQ MC-CDMA is almost insensitive to channel characteristics. The performance can be drastically improved with receive diversity combined with space-time transmit diversity. In addition, the comparison of RCPT HARQ MC-CDMA, orthogonal frequency division multiplexing, and DS-CDMA shows that under similar conditions the throughput of MC-CDMA is the best in a frequency selective fading channel.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제2권12호
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• pp.511-516
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• 2013

20여년 이전의 사회적 여건과 행정환경을 전제로 만들어진 현행 신분증은 매년 위 변조 사례가 증가하고 있다. 이에 따라, 신분증 위 변조로 인한 불법대출 등 각종 범죄행위가 증가하고, 공공기관의 업무지장이 초래되는 등 많은 선의의 피해가 발생하고 있다. 또한, 정보화 사회가 진전되면서 프라이버시 보호가 매우 중요해지고 있다. 하지만 주민등록증은 이름, 주민등록번호, 사진, 주소, 지문 등 사용자의 개인정보가 그대로 노출되어 개인정보 도용사고가 지속적으로 증가하고 있다. 이에 따라, 본 논문에서는 주민등록증의 위 변조 및 프라이버시 보호의 문제점을 살펴보고 이를 보완할 수 있는 차세대 본인확인수단을 제안한다. 이는 국가신분증의 가장 중요한 기능인 사용자 본인확인에 충실하기 위해 위 변조 방지 및 프라이버시 보호를 최우선 목표로 하였다.

• ETRI Journal
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• 제42권5호
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• pp.721-733
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• 2020

Recently, there is an increasing demand for ultra-low-latency (ULL) services such as factory automation, autonomous driving, and telesurgery that must meet an end-to-end latency of less than 10 ms. Fifth-generation (5G) New Radio guarantees 0.5 ms one-way latency, so the feasibility of ULL services is higher than in previous mobile communications. However, this feasibility ensures performance at the radio access network level and requires an innovative 5G network architecture for end-to-end ULL across the entire 5G system. Hence, we survey in detailed two the 3rd Generation Partnership Party (3GPP) standardization activities to ensure low latency at network level. 3GPP standardizes mobile edge computing (MEC), a low-latency solution at the edge network, in Release 15/16 and is standardizing time-sensitive communication in Release 16/17 for interworking 5G systems and IEEE 802.1 time-sensitive networking (TSN), a next-generation industry technology for ensuring low/deterministic latency. We developed a 5G system based on 3GPP Release 15 to support MEC with a potential sub-10 ms end-to-end latency in the edge network. In the near future, to provide ULL services in the external network of a 5G system, we suggest a 5G-IEEE TSN interworking system based on 3GPP Release 16/17 that meets an end-to-end latency of 2 ms.

• 한국전자통신학회논문지
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• 제7권5호
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• pp.1005-1010
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• 2012

증강현실은 차세대에 각광받고 있는 기술로써 카메라로 보이는 현실 공간에 3D 가상 객체를 삽입하는 기술로써 사용자와 객체간의 상호작용을 이용하여 몰입감과 흥미를 유발하여 학습효과를 최대화 할 수 있다. 최근에는 이동성과 휴대성이 뛰어난 모바일이 보편화됨으로써 모바일을 이용한 다양한 증강현실을 선보이고 있다. 본 논문에서는 사용자에게 몰입감과 흥미 위주의 학습내용을 제공하기 위하여 모바일 환경에서 증강되어진 3D 어류백과 시스템을 설계하였다. 본 시스템은 어류백과 사전의 어류그림을 마커로 인식하여 서버에 저장되어진 3D 모델을 불러와서 모바일 환경에서 디스플레이 함으로 어류학습에 도움을 주고자 한다.

• 제어로봇시스템학회논문지
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• 제16권5호
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• pp.440-445
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• 2010

This paper proposes a single accelerometer sensor control algorithm to mobile inverted pendulum, generally called 'Segway', and evaluates the performance of this system comparing to the conventional ones. The commercialized 'Prototype Segway-PT' is initially considered as a next-generation transport vehicle. However, this robot is operated by three gyroscopes and two accelerometers to control the posture and speed, and it requires the complex signal processing for fusing the two sets of data. As the result of this, the growth rate of market size of 'Segway' is slow because of its high price mainly. In this paper, the mobile inverted pendulum is operated by a single accelerometer to simplify the control system to lower the price. Low pass filter is one of the good sensors to reducing the variation of an accelerometer, but it has time delay. This time delay disturbs real-time mobile inverted pendulum control. Like this, other various algorithms are used for this system, but each one has its own weak point. So this paper proposes a new filtering method, median filter and EKF. Median filter is used to image processing to reject impulse elements like salt and pepper noise. As the major performance evaluation parameter for the accelerometer, the high-frequency to low frequency ratio from FFT (Fast Fourier Transform) is used. Effectiveness of the proposed algorithms has been verified through the real experiments and the results are demonstrated.

• 한국IT서비스학회지
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• 제17권3호
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• pp.63-75
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• 2018

In this paper, we propose a testing method of the quality of device application effectively reflecting the necessity of increasing mobile device application quality test, and designed and developed it as a web system. We have studied traditional software testing methods for designing and developing a system. We have developed a next-generation alternative technology that can analyze and compensate for the weaknesses of the web and weaknesses of the Android in order to realize the access system and the responsive web system. As an example applied to the system, we analyzed the requirements of the system implementation and expressed the functions of the system through the use case diagram. The test scenarios were conducted by connecting 5,000 devices to each system using the existing HTTP polling method and the proposed web socket method. After setting the comparative group, the result of the proposed web management system was observed and compared through repeated tests. The research shows that the proposed web socket system has better performance than HTTP polling. The more the number of simultaneous processing of the devices, the lower the server stability but the better the time efficiency. In conclusion, the more the number of devices to be tested is, the more the number of devices can be effectively tested using the proposed web management system.

• 디지털산업정보학회논문지
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• 제19권3호
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• pp.61-75
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• 2023

In this paper, we design and experiment a 5G-based metaverse motion synchronization system with configuration of a mobile motion capture studio that has not been commercialized at home and abroad. As a result of the experiment, the average value of the latency test measurement using Wi-Fi is 0.134 seconds faster than the average latency test measurement value using the 5G network. Existing motion capture studios have spatial limitations as the motion capture range is limited to the Wi-Fi communication range. However, the 5G-based metaverse motion synchronization system configures a mobile motion capture studio so that motion performers can solve the spatial limitations by expanding the motion capture communication range indefinitely regardless of time and place. Therefore, it is possible to implement realistic metaverse contents by displaying a realistic and natural digital human because it is free from spatial constraints. The system which was tested in this paper can create a new business model by converging next-generation technologies that are receiving attention related to the digital virtual world, such as motion capture + 5G + digital human twin + metaverse. And it allows for research and develop a next-generation metaverse-based broadcasting solution at a recent time when the business value of digital human and metaverse technologies and functions has been proven and related sales are growing in earnest.

• 한국산업정보학회논문지
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• 제14권4호
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• pp.30-36
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• 2009

본 논문에서는 SBC(Server Based Computing) 지향 차세대 이동형 단말기 시스템을 제안한다. SBC는 최근 각광받고 있는 시스템이며, 하나의 서버를 통한 다수 개개인의 단말기와 모니터, 키보드만으로 컴퓨터를 이용하는 시스템이며 서버만의 업그레이드로 모든 사용자가 그에 대한 편의성의 극대화 및 가격측면에서 많은 장점을 가진다. 그러나 멀티미디어 스트리밍구현 및 외부기기와의 연결을 통한 디바이스 제어시스템의 실제 시스템 구현에는 설계 및 소프트웨어구현에 많은 어려움이 있다. 본 논문에서는 SBC의 장점을 가지면서 가격면에서의 경쟁력을 가지는, SBC기반 차세대 이동형 단말기를 개발하였다. 또한 다양한 성능시험 결과, 타제품에 비해 가격은 저렴하면서 우수한 멀티미디어 및 보안성에 대한 성능을 검증하였다.

• 한국통신학회논문지
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• 제34권11A호
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• pp.844-851
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• 2009

핸드오버는 multi-hop relay 시스템에서 이동성을 제공하기 위해 필요하다. 핸드오버의 주요 목적은 MS가 한 BS의 air-interface에서 다른 BS의 air-interface로 이동할 때 연속 연결을 제공하는 것이다. 특히 이종기계간의 핸드오버는 차세대 네트워크에 필수적이다. Mobile WiMAX MMR system에서의 수직 핸드오버 기술은 기술자들이 Mobile WiMAX system을 overlaid cell환경으로 가져오는데 매우 유용하다. 이 기술은 Micro cell(Frequency 1,FA1) and Macro cell(Frequency 2,FA2)사이에 놓인 Ubiquitous 환경에서 시스템 성능향상을 위해 MRS를 다른 시스템으로 핸드오버 하는 기술에 적용될 것이다. 이 논문에서 FA1과 FA2 주파수를 사용하여 제안된 조건들에 따라 MRS들이 수직 핸드오버를 수행했다. 그리고 중심에 있는 Macro cell과 그것을 싸고 있는 6개의 Macro cell들의 BS나 섹터로부터 받은 간섭 및 성능을 분석한다.