• Title, Summary, Keyword: spectrum

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Analysis of Radio Spectrum Policy for the Fifth Generation Mobile Communications (5G 이동통신을 위한 전파정책 분석)

  • Kim, Chang-Joo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.8
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    • pp.679-689
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    • 2015
  • The 5G mobile communication technologies have been extensively developed with the era of mobile broadband, but spectrum policy for this service has not yet set up. In this paper, We have investigated the 5G mobile service and analyzed the 5G spectrum policy taking the developing technologies into account. Based on the results of these analyses, We propose an expansion of spectrum sharing in the 3~5 GHz bands, spectrum harmonization of 5 GHz bands, and restructuring of spectrum management administration from currently three distributed management to centralized spectrum management structure.

Spectrum Hole Utilization in Cognitive Two-way Relaying Networks

  • Gao, Yuan;Zhu, Changping;Tang, Yibin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.3
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    • pp.890-910
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    • 2014
  • This paper investigates the spectrum hole utilization of cooperative schemes for the two-way relaying model in order to improve the utilization efficiency of limited spectrum holes in cognitive radio networks with imperfect spectrum sensing. We propose two specific bidirectional secondary data transmission (BSDT) schemes with two-step and three-step two-way relaying models, i.e., two-BSDT and three-BSDT schemes, where the spectrum sensing and the secondary data transmission are jointly designed. In the proposed cooperative schemes, the best two-way relay channel between two secondary users is selected from a group of secondary users serving as cognitive relays and assists the bi-directional communication between the two secondary users without a direct link. The closed-form asymptotic expressions for outage probabilities of the two schemes are derived with a primary user protection constraint over Rayleigh fading channels. Based on the derived outage probabilities, the spectrum hole utilization is calculated to evaluate the percentage of spectrum holes used by the two secondary users for their successful information exchange without channel outage. Numerical results show that the spectrum hole utilization depends on the spectrum sensing overhead and the channel gain from a primary user to secondary users. Additionally, we compare the spectrum hole utilization of the two schemes as the varying of secondary signal to noise ratio, the number of cognitive relays, and symmetric and asymmetric channels.

An Oligopoly Spectrum Pricing with Behavior of Primary Users for Cognitive Radio Networks

  • Lee, Suchul;Lim, Sangsoon;Lee, Jun-Rak
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.4
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    • pp.1192-1207
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    • 2014
  • Dynamic spectrum sharing is a key technology to improve spectrum utilization in wireless networks. The elastic spectrum management provides a new opportunity for licensed primary users and unlicensed secondary users to efficiently utilize the scarce wireless resource. In this paper, we present a game-theoretic framework for dynamic spectrum allocation where the primary users rent the unutilized spectrum to the secondary users for a monetary profit. In reality, due to the ON-OFF behavior of the primary user, the quantity of spectrum that can be opportunistically shared by the secondary users is limited. We model this situation with the renewal theory and formulate the spectrum pricing scheme with the Bertrand game, taking into account the scarcity of the spectrum. By the Nash-equilibrium pricing scheme, each player in the game continually converges to a strategy that maximizes its own profit. We also investigate the impact of several properties, including channel quality and spectrum substitutability. Based on the equilibrium analysis, we finally propose a decentralized algorithm that leads the primary users to the Nash-equilibrium, called DST. The stability of the proposed algorithm in terms of convergence to the Nash equilibrium is also studied.

Evaluation of Response Spectrum Shape Effect on Seismic Fragility of NPP Component (스펙트럼 형상이 원전 기기 지진취약도에 미치는 영향 평가)

  • 최인길;서정문;전영선;이종림
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.4
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    • pp.23-30
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    • 2003
  • The result of recent seismic hazard analysis indicates that the ground motion response spectra for Korean nuclear power plant site have relatively large frequency acceleration contents. In the ordinary seismic fragility analysis of nuclear power plant structures and equipments, the safety margin of design ground response spectrum is directly used as a response spectrum shape factor. The effects of input response spectrum shape on the floor response spectrum were investigated by performing the direct generation of floor response spectrum from the ground response spectrum. The safety margin included in the design ground response spectrum should be considered as a floor response spectrum shape factor for the seismic fragility analysis of the equipments located in a building.

Analysis of Radio Spectrum Charges based on Economic Value (주파수의 경제적 가치를 고려한 할당대가 산정기준 분석)

  • Jang, Hee-Seon;Yeo, Jae-Hyun;Lee, Kwang-Hee;Choi, Ki-Seok
    • Journal of Korean Institute of Industrial Engineers
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    • v.34 no.2
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    • pp.216-222
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    • 2008
  • The determination of spectrum charges for the operators is a main issue to efficiently manage the limited radio spectrum resources. In this paper, we propose a model to compute the optimal charges for radio spectrum usage. The objective is to determine that will maximize the spectrum charges, and decision variables of ratios for actual or estimated revenues are considered. The spectrum charges are maximized under satisfying the least profit for operators based on Log-Linear demand function. The parameters of actual sales and minimum profit of operators are analyzed to make an efficient management for radio spectrum. The results show that the spectrum charges increase as the actual sales increase, but it decrease as the required minimum profit of operator increases. It is also observed that the government should increase the ratio for estimated sales if anticipating the poor market in the future, otherwise they should increase the ratio for actual sales to maximize the spectrum charges.

Analysis on 3G Mobile Spectrum Charges by International Comparison (국제간 비교를 통한 3세대 이동통신 주파수 할당대가 분석)

  • Kim, Tae-Sung;Kim, Min-Jeong;Jun, Hyo-Jung
    • 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.

A Cooperative Spectrum Sensing and Dynamic Spectrum Decision Methods for Heterogeneous Cognitive Radio Network (이종 인지 라디오 네트워크에서 협력 스펙트럼 센싱 및 동적 스펙트럼 결정 방법)

  • Kim, Nam-Sun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.7A
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    • pp.560-568
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    • 2012
  • Spectrum sensing and spectrum decision are the main functions that cognitive radios (CRs) have to perform in order to get the best available spectrum band for the establishment of a wireless communication. These problems are worsened in the presence of users with different demands and spectrum channels with different properties in a heterogeneous network. The primary objective in this work is to design and simulate a new spectrum decision algorithm for heterogeneous cognitive radio system. To this end, first, we consider all cognitive users are separated into different traffic classes according to their Quality of Service (QoS). The cognitive users within one traffic class perform spectrum sensing in centralized group-based cooperative spectrum sensing system and the users of different traffic classes share the sensing results. Second, we propose a novel use of the Analytic Hierarchy Process (AHP) to optimally select available bands according to user requirements and detected spectrum channel characteristics (SCC). In this paper, utility function is used as spectrum decision algorithm. Simulation results demonstrate that the proposed method shows can effectively select the best available spectrum channels with a low complexity.

An Improved Cross Entropy-Based Frequency-Domain Spectrum Sensing (Cross Entropy 기반의 주파수 영역에서 스펙트럼 센싱 성능 개선)

  • Ahmed, Tasmia;Gu, Junrong;Jang, Sung-Jeen;Kim, Jae-Moung
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.48 no.3
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    • pp.50-59
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    • 2011
  • In this paper, we present a spectrum sensing method by exploiting the relationship of previous and current detected data sets in frequency domain. Most of the traditional spectrum sensing methods only consider the current detected data sets of Primary User (PU). Previous state of PU is a kind of conditional probability that strengthens the reliability of the detector. By considering the relationship of the previous and current spectrum sensing, cross entropy-based spectrum sensing is proposed to detect PU signal more effectively, which has a strengthened performance and is robust. When previous detected signal is noise, the discriminating ability of cross entropy-based spectrum sensing is no better than conventional entropy-based spectrum sensing. To address this problem, we propose an improved cross entropy-based frequency-domain spectrum sensing. Regarding the spectrum sensing scheme, we have derived that the proposed method is superior to the cross entropy-based spectrum sensing. We proceed a comparison of the proposed method with the up-to-date entropy-based spectrum sensing in frequency-domain. The simulation results demonstrate the performance improvement of the proposed spectrum sensing method.

A Channel Allocation Scheme Based on Spectrum Hole Prediction in Cognitive Radio Wireless Networks (무선인지 통신망에서 스펙트럼 홀 예측에 의한 채널할당)

  • Lee, Jin-yi
    • Journal of Advanced Navigation Technology
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    • v.19 no.4
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    • pp.318-322
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    • 2015
  • In wireless communication networks, most of the prediction techniques are used for predicting the amount of resource required by user's calls for improving their demanding quality of service. However, we propose a channel allocation scheme based on predicting the resources of white spectrum holes for improving the QoS of rental user's spectrum handoff calls for cognitive radio networks in this paper. This method is supported by Wiener predictor to predict the amount of white spectrum holes of license user's free spectrum resources. We classify rental user's calls into initial calls and spectrum handoff calls, and some portion of predicted spectrum-hole resources is reserved for spectrum handoff calls' priority allocation. Simulations show that the performance of the proposed scheme outperforms in spectrum handoff call's dropping rate than an existing method without spectrum hole prediction(11% average improvement in 50% reservation).

Policy Agendas for the Efficient Use of Public and Broadcast Spectrum (공공 및 방송주파수의 효율적 이용을 위한 정책 과제)

  • Yeon, Kwon-Hum;Kim, Yongkyu
    • 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.