• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.4B
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• pp.371-377
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• 2011

Users of the Information Age, IT usage patterns of the wired broadband information services and various forms of the same quality wireless multimedia services are required. Changes of these times the next-generation mobile communications (IMT-Advanced) has emerged as the necessity of developing its current voice and packet data communications on the move in the high-speed 100Mbps, 1Gbps in stationary and slow data transmission rates up to fixed-mobile convergence based on needed to provide ubiquitous service platform for the realization of IMT-Advanced is the time for preparation. In particular, 3-5GHz band, focused on mobile communications can be used to secure the necessary frequency band relocated and the existing crosstalk analysis methodology developed for the services rendered, and the frequency of such results to obtain new spectrum for IMT-Advanced for the country to secure the frequency characteristics and IMT-Advanced 3-5GHz band for the radio frequency of the characterization techniques necessary to develop a national wireless communication interference and frequency-based technology acquisition and management skills were identified.

• Journal of Advanced Information Technology and Convergence
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• v.8 no.2
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• pp.1-11
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• 2018

Multimedia contents have been increasingly available over the Internet as wireless networks systems are continuously growing popular. Unlimited access from various users has led to unauthorized access of third parties or adversaries. This paper deals with the implementation of elliptic curve cryptography (ECC) based user authentication for securing multimedia contents over the Internet. The ECC technique has been incorporated with the advanced encryption standard (AES) algorithm to ensure the complexity of the proposed authentication scheme and to guarantee authenticity of multimedia services.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.552-555
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• 2002

Wideband CDMA is one of the radio access technologies for the third generation in which voice is the basic service. There has been lot of research work in order to find out the suitable transmission scheme to meet the requirement of accommodating variable type of services in Wideband-CDMA. This paper studies the behavior of different services using different transmission schemes in Wideband CDU and compares their performance in terms of BER. Different transmission schemes are found to be suitable for different services. Transmission schemes used are- fixed processing gain scheme also called as variable bandwidth scheme, single code transmission and multicode transmission. It is found that fixed processing gain scheme is suitable fur high data rates. Single code transmission is suitable fer low data rates where as multicode transmission is suitable for low and medium data rates.

• Journal of Communications and Networks
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• v.18 no.4
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• pp.619-628
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• 2016

This paper describes a theoretical framework for rate allocation to maximize the power efficiency of overall heterogeneous wireless networks whose users are assumed to have multihoming capabilities. Therefore, the paper first presents a power consumption model considering the circuit power and radio transmission power of each wireless network. Using this model, two novel power efficient rate allocation schemes (PERAS) for multihoming services are proposed. In this paper, the convex optimization problem for maximizing the power efficiency over wireless networks is formulated and solved while guaranteeing the required quality of service (QoS). Here, both constant bit rate and variable bit rate services are considered. Furthermore, we extend our theoretical framework by considering the sleep-operation management of wireless networks. The performance results obtained from numerical analysis reveal that the two proposed schemes offer superior performance over the existing rate allocation schemes for multihoming services and guarantee the required QoS.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6B
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• pp.527-533
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• 2006

In this paper, we analyze the performance of MAC (Media Access Control) layer in DSRC (Dedicated Short Range Communication). It will be widely applied for ITS (Intelligent Transportation System) services; for example ETC (Electric Toll Control), BIS (Bus Information System) etc., needed to small packet size. But If ITS service is evolving to advance ITS, ADIS (Advanced Driver Information Systems) and AVHS (Advanced Vehicle Highway System) etc, be needed larger packet size. In the future, it may offer more various services such as traffic information, collection, and multimedia information. There are two kind of physical media, IR(Infrared) and RF(Radio frequency). And each system has their own protocol that is adaptive in special characteristics of physical medium for using efficiently limited radio resources. In this paper, we analyze the special characteristics of each system. And we study practical use of some related services expected to be used in the near future, by analyzing the transmission efficiency in each DSRC system.

• Journal of the Korea Society of Computer and Information
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• v.20 no.6
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• pp.29-35
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• 2015

The heterogeneous LTE (Long Term Evolution)-Advanced networks comprising a macrocell and femtocells can provide an efficient solution not only to extend macrocell coverage but also to deal with packet traffics increasing explosively within macrocells. An efficient resource management scheme is necessary to maintain the QoS (Quality of Service) of mobile multimedia services because the LTE-Advanced system should support not only voice but also mobile applications such as data, image and video. This paper proposes a resource management scheme to guarantee QoS continuity of multimedia services and to maximize the resource utilization in OFDMA (Orthogonal Frequency Division Multiple Access) based LTE-Advanced systems. This scheme divides the resources into several service blocks and allocates those resources based on the competition between macrocell and femtocell. Simulation results show that it provides better performances than the conventional one in respect of handover failure rate and blocking rate.

• 한국ITS학회:학술대회논문집
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• v.2007 no.10
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• pp.289-296
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• 2007

• Journal of the Korean Home Economics Association
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• v.45 no.9
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• pp.75-87
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• 2007

This study was conducted to determine what information regarding wedding services are most important to consumers, and the most common methods by which consumers gather this information so that wedding directors can disseminate information regarding wedding services effectively. In addition, this survey also evaluated the amount of information required by wedding directors so that they can best serve consumers. To accomplish these goals, a questionnaire survey was conducted between January 25 and February 27, 2007. A total of 290 questionnaires were used for the final analysis, which indicated that: 1. The needs for information related to wedding services was very high as index value 4.41. 2. Most consumers acquire information regarding wedding services while attending other wedding ceremonies and consumers value the advice of families, friends and relatives over information they obtain from the internet. 3. Consumers would like a wedding director to manage the wedding schedule and arrange the wedding procedure.

• International journal of advanced smart convergence
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• v.2 no.1
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• pp.24-26
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• 2013

In the process of a mobile network evolution to the All-IP, it is inevitable to experience a transient period embracing both circuit and packet based data traffics. At the stage of those hybrid networks, it is important to build them in an efficient manner in terms of resource utilization which is closely related to the overall system operation cost. Especially, the multimedia telephony is one of the essential services in the advanced packet based mobile networks. In this paper an effective method of system operation is proposed for building up the multimedia telephony service while the legacy network co-exists. The proposed solution is based on the careful investigation of the usage pattern of the multimedia services in the evolving networks. This method is also expected to be a useful guideline for the network resource planning.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.8B
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• pp.962-970
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• 2011

This paper describes an advanced unified communication system. The advanced unified communications mean a service that integrates basic communications such as call, SMS, email, and chatting with social networking service considered as a new communication channel, presenting a unified user interface. The advanced unified communication system is composed of advanced UC(Unified Communications) applications, open UC service platform, and UC back-end servers. The advanced UC applications consist of web-based application and smart phone application. The open UC service platform provides a variety of service components that enable the third party applications to access basic communications and social network services within an enterprise. The UC back-end servers provide server functionalities for call, SMS, email, and chatting.