• Journal of Digital Convergence
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• v.12 no.12
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• pp.37-47
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• 2014

The characteristics of the spectrum, which are necessary for mobile telecommunication services, may determine the advantage of operators' competition for mobile services. We have a focus on the possibility that there would be the core spectrum within the frequencies. We define the core spectrum of frequencies in terms of 4 criteria (global source/roaming, cost-effectiveness, the experience of utilization and the possibility of use). They are based on the aspects of applicative and economic effectiveness by not technological and but market conditions. We have explored the current core spectrum by using the stepwise selection from these criteria. Our result indicates that the core spectrum may be movable with the development of technology and the flow of time. The results of this paper could be practically used as the reasonable justifications of the policies for not only the competition management but also the alignment about the frequencies for mobile telecommunication.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11B
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• pp.1261-1271
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• 2009

Emergence of new mobile communication services has generated new demand for spectrum. Because spectrum is a scarce public resource, demand for spectrum would exceed supply. As the demand for spectrum grows, the spectrum management policy becomes one of the most important issues in mobile telecommunications industry. Huge license charges for spectrum usage may obstruct the growth of mobile telecommunications industry. We analyze spectrum charges by international comparison for the case of 3G mobile telecommunication spectrum assignment. There are mainly two types of methods in spectrum assignment of 3G service, one is the auction and the other is the beauty contest. This article aims to analyze factors which influence on spectrum charges and to study the characteristic of spectrum charges of some selected countries. This study suggests the multiple regression model about spectrum charges.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.1
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• pp.253-259
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• 2017

As ICT industrial paradigm changes and wireless communication services evolve, demands on spectrum information are soaring. We conducted demand survey of experts and public in general on spectrum information and prioritized what we should disclose. And we looked into overseas cases and analyzed their policy, the current status, exceptions for opening spectrum information. In this paper, we suggested a direction on how to make spectrum information public in Korea. Also, we made a proposal to establish management system and legislation for opening spectrum information.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.8
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• pp.849-859
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• 2013

This paper explores the policy alternatives to promote efficient use of spectrums for public use and terrestrial broadcasting, which are essential to provide spectrum for mobile broadband services. To this end, recent overseas spectrum management policies are introduced and utilized to provide domestic policy alternatives. For the efficient use of spectrum for public use, policy alternatives such as detailed survey of current usage of spectrum for public use, levying the opportunity cost, installment of spectrum efficiency fund, providing incentives for the efficient use of spectrum for military use, and introduction of shared use are proposed. For the efficient use of spectrum for terrestrial broadcasting, short-term policy alternative such as change of contribution rate base of the broadcasting - telecommunications development fund is proposed. For long-term policy alternatives, change of spectrum provision from designation to allocation for the spectrum for commercial terrestrial broadcasting and introduction of administered incentive pricing to public terrestrial broadcasting are proposed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.8
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• pp.828-837
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• 2014

With the rapid development of radio technologies, there have been actively researching the convergence between radio technology and other industry as well as wireless communications itself. In this paper, we investigate the paradigm shift of radio policy as radio technologies such as small cells and cognitive radio advance, and analyze the directions of spectrum policy and radio technology to promote the creative use of radio waves. In particular, we propose the spectrum policy for the expansion of open spectrum policy, technology development of interference management, and restructuring of the Korean radio law.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.11
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• pp.4387-4404
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• 2015

The energy-efficient design of sensing-based spectrum sharing of a multi-input and multi-output (MIMO) cognitive radio (CR) system with imperfect multiple antenna spectrum sensing is investigated in this study. Optimal resource allocation strategies, including sensing time and power allocation schemes, are studied to maximize the energy efficiency (EE) of the secondary base station under the transmit power and interference power constraints. EE problem is formulated as a nonlinear stochastic fractional programming of a nonconvex optimal problem. The EE problem is transformed into its equivalent nonlinear parametric programming and solved by one-dimension search algorithm. To reduce searching complexity, the search range was founded by demonstration. Furthermore, simulation results confirms that an optimal sensing time exists to maximize EE, and shows that EE is affected by the spectrum detection factors and corresponding constraints.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.5
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• pp.1101-1105
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• 2013

Due to underutilization of spectrum under the current static spectrum management policy, various kinds of dynamic spectrum access strategies have appeared. Myopic policy is a simple policy with reduced complexity that maximizes the immediate throughput. In this paper, the distribution of its medium access delay is evaluated under saturation traffic conditions. Using the distribution of the medium access delay, we also evaluate its system delay under non-saturated traffic conditions.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.4
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• pp.81-87
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• 2016

Recently, as the heterogeneous network (HetNet) has been deployed widely to support various kinds of Radio Access Networks(RANs) with a combination of Macro, Pico, and/or Femto cells, research and standardization efforts have been very active regarding the concept of Licensed Shared Access (LSA) for supporting spectrum sharing. In order for a mobile device to efficiently support the spectrum sharing, the mobile device shall be reconfigurable, meaning that its radio application code has to be adaptively changed in accordance with the hopping of desired spectral band. Especially, Working Group 2 (WG2) of Technical Committee (TC) Reconfigurable Radio System (RRS) of European Telecommunications Standards Institute (ETSI) has been a main driving force for developing standard architecture for Multi-mode Mobile Device (MD) that can be applied to the LSA system. In this paper, we introduce the Multi-mode MD architecture for supporting LSA-based spectrum sharing. An implementation of a test-bed of Multi-mode MD is presented in order to verify the feasibility of the standard MD architecture for the purpose of LSA-based spectrum sharing through various experimental tests.

• Journal of Digital Convergence
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• v.11 no.7
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• pp.261-269
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• 2013

Ubiquitous healthcare is a recent technology and a new methodology of medical diagnosis and medical care. However, in order for u-Healthcare service to become a general technology, there are some technological barriers(mobility, minimization, battery consumption etc) to overcome. In this paper, we developed a spectrum analysis system for smart phones. The results showed that compared to other solutions, our's were not only small in size but also almost the same in performance(reproducibility comparison experiments, Spectrum, Calibration Curve and Prediction). Therefore, the proposed solution is expected to be widely used in u-Health area.

• The Journal of the Korea Contents Association
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• v.8 no.8
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• pp.28-36
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• 2008

The worth of frequency resources is growing up because of development of wireless communication. However, frequency resources is short, because demand is much more than supply. So it needs Cognitive Radio(CR), which manages frequency resources efficiently. In this paper, we apply the efficient Spectrum Sensing method based on CR in an embedded board. We examine various Spectrum Sensing methods and apply these methods to an embedded platform on CR environment and verify the performance through the MAC message.