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A microcell is a cell in a mobile phone network served by a low power cellular base station (tower), covering a limited area such as a mall, a hotel, or a transportation hub. A microcell is usually larger than a picocell, though the distinction is not always clear. A microcell uses power control to limit the radius of its coverage area. Typically the range of a microcell is less than two kilometers wide, whereas standard base stations may have ranges of up to 35 kilometres (22 mi). A picocell, on the other hand, is 200 meters or less, and a femtocell is on the order of 10 meters,〔http://www.visionmobile.com/blog/2007/12/do-we-really-need-femto-cells/〕 although AT&T calls its femtocell that has a range of , a "microcell".〔http://www.wireless.att.com/learn/why/3gmicrocell/faq.jsp〕 AT&T uses "AT&T 3G MicroCell" as a trade mark and not necessarily the "microcell" technology, however. A microcellular network is a radio network composed of microcells. == Rationale == Like picocells, microcells are usually used to add network capacity in areas with very dense phone usage, such as train stations. Microcells are often deployed temporarily during sporting events and other occasions in which extra capacity is known to be needed at a specific location in advance. Cell size flexibility is a feature of 2G (and later) networks and is a significant part of how such networks have been able to improve capacity. Power controls implemented on digital networks make it easier to prevent interference from nearby cells using the same frequencies. By subdividing cells, and creating more cells to help serve high density areas, a cellular network operator can optimize the use of spectrum and ensure capacity can grow. By comparison, older analog systems have fixed limits beyond which attempts to subdivide cells simply would result in an unacceptable level of interference. 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「Microcell」の詳細全文を読む スポンサード リンク
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