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Radio resource management (RRM) is the system level control of co-channel interference and other radio transmission characteristics in wireless communication systems, for example cellular networks, wireless networks and broadcasting systems.〔J. Zander, S-L Kim, M. Almgren, Radio Resource Management, Artech House Publishers, ISBN 1-58053-146-6, 2001.〕〔N. D. Tripathi, J. H. Reed, H. F. Vanlandingham, (Radio Resource Management in Cellular Systems ), Springer, ISBN 0-7923-7374-X, 2001.〕 RRM involves strategies and algorithms for controlling parameters such as transmit power, user allocation, beamforming, data rates, handover criteria, modulation scheme, error coding scheme, etc. The objective is to utilize the limited radio-frequency spectrum resources and radio network infrastructure as efficiently as possible. RRM concerns multi-user and multi-cell network capacity issues, rather than the point-to-point channel capacity. Traditional telecommunications research and education often dwell upon channel coding and source coding with a single user in mind, although it may not be possible to achieve the maximum channel capacity when several users and adjacent base stations share the same frequency channel. Efficient dynamic RRM schemes may increase the system spectral efficiency by an order of magnitude, which often is considerably more than what is possible by introducing advanced channel coding and source coding schemes. RRM is especially important in systems limited by co-channel interference rather than by noise, for example cellular systems and broadcast networks homogeneously covering large areas, and wireless networks consisting of many adjacent access points that may reuse the same channel frequencies. The cost for deploying a wireless network is normally dominated by base station sites (real estate costs, planning, maintenance, distribution network, energy, etc.) and sometimes also by frequency license fees. The objective of radio resource management is therefore typically to maximize the system spectral efficiency in ''bit/s/Hz/area unit'' or ''Erlang/MHz/site'', under some kind of user fairness constraint, for example, that the grade of service should be above a certain level. The latter involves covering a certain area and avoiding outage due to co-channel interference, noise, attenuation caused by path losses, fading caused by shadowing and multipath, Doppler shift and other forms of distortion. The grade of service is also affected by blocking due to admission control, scheduling starvation or inability to guarantee quality of service that is requested by the users. While classical radio resource managements primarily considered the allocation of time and frequency resources (with fixed spatial reuse patterns), recent multi-user MIMO techniques enables adaptive resource management also in the spatial domain.〔E. Björnson and E. Jorswieck, (Optimal Resource Allocation in Coordinated Multi-Cell Systems ), Foundations and Trends in Communications and Information Theory, vol. 9, no. 2–3, pp. 113–381, 2013.〕 In cellular networks, this means that the fractional frequency reuse in the GSM standard has been replaced by a universal frequency reuse in LTE standard. == Static radio resource management == Static RRM involves manual as well as computer-aided fixed cell planning or radio network planning. Examples: * Frequency allocation band plans decided by standardization bodies, by national frequency authorities and in frequency resource auctions. * Deployment of base station sites (or broadcasting transmitter site) * Antenna heights * Channel frequency plans * Sector antenna directions * Selection of modulation and channel coding parameters * Base station antenna space diversity, for example * * Receiver micro diversity using antenna combining * * Transmitter macro diversity such as OFDM single frequency networks (SFN) Static RRM schemes are used in many traditional wireless systems, for example 1G and 2G cellular systems, in today's wireless local area networks and in non-cellular systems, for example broadcasting systems. Examples of static RRM schemes are: * Circuit mode communication using FDMA and TDMA. * Fixed channel allocation (FCA) * Static handover criteria 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Radio resource management」の詳細全文を読む スポンサード リンク
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