• 디지털산업정보학회논문지
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• 제11권1호
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• pp.19-25
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• 2015

In this time, as an industrial society developed to a welfare society, more and more people want their quality of lives upgraded and specially customized service by mass production/mass consumption. And it leads to an increase of requiring service. There're active developments and studies on various IT equipment as the requirement made IT devices used in service. In this paper, we try to design and realize radio paging DID by using smart device to be used as a receiver of a radio pager which is broadly used at face to face service. Firstly, we used MCU to design and implement Wireless Calling Gateway which change radio calling signal of ISM band to smart device. A receiver of wireless caller used original receiver module. Also it used bluetooth module to communicate with smart device. It was possible to have satisfactory communication since radio paging signal converter and smart device were linked in 3M. Secondly, to indicate various paging information delivered from a radio pager, we realized DID application program by using Smart PAD. As a result, we could indicate various information compared to an original receiver which only could indicate letters or numeric data. Secondly, we implemented the DID app for wireless calls that can display a variety of information sent from a wireless pager. Was implemented using the Smart Pad. As a result, it is shown that can display a variety of information than the existing receiver.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권11호
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• pp.4068-4086
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• 2014

Due to the prevalence of powerful mobile terminals and the rapid advancements in wireless communication technologies, the wireless video streaming service has become increasingly more popular. Recent studies show that video streaming services via Transmission Control Protocol (TCP) are becoming more practical. TCP has more advantages than User Diagram Protocol (UDP), including firewall traversal, bandwidth fairness, and reliability. However, each video service shares an equal portion of the limited bandwidth because of the fair sharing characteristics inherent in TCP and this bandwidth fair sharing cannot always guarantee the video quality for each user. To solve this challenging problem, an Adaptive Multiple TCP (AM-TCP) scheme is proposed in this paper to guarantee the video quality for mobile devices in wireless networks. AM-TCP adaptively controls the number of TCP connections according to the video Rate Distortion (RD) characteristics of each stream and network status. The proposed scheme can minimize the total distortion of all participating video streams and maximize the service quality by guaranteeing the quality of each video streaming session. The simulation results show that the proposed scheme can significantly improve the quality of video streaming in wireless networks.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2000년도 추계학술발표논문집 (하)
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• pp.1051-1054
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• 2000

IMT-2000 moving picture messaging service is a primary auxiliary connection service that allows a caller to leave a message when the caller can not complete the call. As the number of service subscriber for wireless communication is dramatically increased, various wireless services as well as simple connection service are requried IMT-2000 moving picture messaging service increases the call completion rate and makes it possible to provide various services.

• 정보처리학회논문지D
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• 제11D권4호
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• pp.951-958
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• 2004

본 논문에서는 GPRS망으로 이동한 이동 ISP 가입자가 GPRS망을 접속하여 무선 인터넷 서비스를 받을 때 필요한 홈 ISP망의 동적 내 주소할당에 대한 문제점을 살펴보고 그 해결 방안으로 홈 ISP망 내 특수(specific) DHCP Relay를 개발하여 운영하는 방법을 제시했다. 실제 GPRS core network testbed와 ISP망을 구축하고 특수 DHCP Relay를 개발해서 GPRS망으로 이동한 이동 ISP 가입자에게 홈 ISP망의 동적 IP 주소 할당을 과정과 결과를 시뮬레이션을 통해 확인하였다.

• 한국전자통신학회논문지
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• 제10권12호
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• pp.1361-1366
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• 2015

국내에서는 대중교통 내에서 사회적 약자를 위한 노약자석과 더불어 임산부석을 제공하고 있다. 그러나, 임산부가 임산부석에 접근하더라도 임산부임을 인지하지 못하거나 무시함으로써 임산부석에 대한 활용도가 떨어진다. 본 논문에서는 현재 임산부석의 문제점에 대해 알아보고, 무선통신기술을 이용하여 임산부가 임산부석에 접근시 이를 주위에 알려주는 임산부 알림 서비스에 대해 제안한다. 먼저 서비스의 개념 및 시나리오에 대해 소개한 후 서비스를 가능하게 하는 무선통신기술과 관련한 각 기술들의 특징에 대해 알아본다. 또한 실제 시스템 구현을 위해 고려해야 할 사항들에 대해 논의한다.

• 한국인터넷방송통신학회논문지
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• 제11권6호
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• pp.127-134
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• 2011

최근 각광받고 있는 무선 데이터 통신 인프라는 유선에서의 한계점을 넘어 빠른 속도로 발전 하고 있다. 특히, 이를 이용한 u-Healthcare 서비스에 대한 이슈가 증가하고 있으며, 원활한 서비스 제공을 위해서는 무선 데이터망의 품질 보장에 대한 연구가 중요하다. 그러나 기존 연구는 유선망에 대한 종단간 품질관리만을 집중 수행하고 있기 때문에 무선망에 대한 품질관리 연구가 미비하다. 본 논문은 이에 대한 연구로 u-Healthcare 서비스를 제공받는 무선 데이터 망 사용자의 품질 보장 및 사용자 요구를 만족시키기 위한 방안인 무선 환경을 고려한 무선서비스 품질측정 기준을 제시하였다. 이를 위해 무선데이터 품질 측정 지표 및 기준을 선정하였고, 품질 측정 평가 방안을 서비스별로 제시하였으며, 각각의 서비스 별로 품질지표를 제시하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권6호
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• pp.2680-2696
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• 2018

The collaborative content caching system is an effective solution developed in recent years to reduce transmission delay and network traffic. In order to decrease the service end-to-end transmission delay for future 5G ultra-dense networks (UDN), this paper proposes a novel service migration method that can guarantee the continuity of service and simultaneously reduce the traffic flow in the network. In this paper, we propose a service migration optimization model that minimizes the cumulative transmission delay within the constraints of quality of service (QoS) guarantee and network condition. Subsequently, we propose an improved firefly algorithm to solve this optimization problem. Simulation results show that compared to traditional collaborative content caching schemes, the proposed algorithm can significantly decrease transmission delay and network traffic flow.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 통신소사이어티 추계학술대회논문집
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• pp.353-356
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• 2003

As the wireless mobile telecommunication system has been developed with astonishment, its offering service has also widely been expanded including various data service. Currently, the wireless mobile telecommunication network presents voice service that covers for the most part of the whole service areas. For this reason, the availability of the switching capacity in the mobile switching center(MSC) is manipulated by the required volume of voice service. However, considering the increase of data service, it is desirable for the current switching method to be modified for more efficiency. In this Paper, we analyze the data traffic caused by providing data service in the wireless mobile telecommunication network. For this, we are firstly going to review the result of the analysis in the feature of the data traffic. Secondly, based on the review, we are also going to perform analyzing the other feature of the data traffic normally generated in the wireless mobile telecommunication network. We expect that this paper would be utilized as an elementary source for the feature of the SMS data .traffic and it will be an honour for ourselves to work on it.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2009년도 정보통신설비 학술대회
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• pp.211-214
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• 2009

In this paper, we present an efficient handover method avoiding ping-pong phenomenon in Wireless LAN systems. In order to provide the seamless VoIP service for terminals with mobility in Wireless LAN systems. Since the variation range of the received signal strength of the moving terminals is large, the handover procedure can be started by an instant drop of the signal strength. Then the handover procedure is repeated, which makes ping-pong phenomenon. Since the quality of service of VoIP can be lowered by ping-pong phenomenon, in this paper, we present the necessary condition to avoid the ping-pong phenomenon. Through LAB test, we show that the proposed handover method can provide an seamless service without the ping-pong phenomenon.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2006년도 하계학술대회
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• pp.47-52
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• 2006

In this paper, we suggested new network architecture to provide seamless service between the cellular system and new wireless broadband network such as IEEE 802.16e, called WiBro. The interworking technologies are very important issue because mobile operator should provide service connectivity between various wireless networks based on different access technologies. Moreover a change and modification on legacy network should be minimized for providing interworking with new wireless broad-band network. We implemented proposed interworking architecture between 3G cellular network and 802.16e network to provide seamless service including interworking unit in real test environment. Also, we performed performance evaluation in hybrid network environments.