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Freedom of Mobile Multimedia Access (FOMA) is the brand name of the W-CDMA-based 3G telecommunications services being offered by the Japanese telecommunications service provider NTT DoCoMo. It is an implementation of the Universal Mobile Telecommunications System (UMTS) and was the world's first 3G service to commence operation. NTT DoCoMo also offers HSPA services branded FOMA High-Speed (FOMAハイスピード), which offers downlink speeds up to 7.2 Mbit/s and uplink speeds up to 5.7 Mbit/s. ==History== NTT DoCoMo developed the W-CDMA air interface, which is a form of DS-CDMA (Direct Sequence CDMA), in the late 1990s. It was later accepted by ITU as one of several air interfaces for IMT-2000 and by ETSI as one of three air interfaces for the UMTS. NTT DoCoMo originally planned to launch the world's first 3G services, initially branded Frontier of Mobile Multimedia Access (FOMA), in May 2001. However, by May 2001, NTT DoCoMo had postponed the full-scale launch until October 2001, claiming they had not completed testing of their entire infrastructure, and would only launch an introductory trial to 4,000 subscribers. In doing so, they also renamed the service to Freedom of Mobile multimedia Access.〔 In June 2001 trial subscribers complained the mobile phones had insufficient battery life and crashed frequently, that there was inadequate network coverage, and that there were security issues within the handset itself.〔 As a result, DoCoMo recalled 1,500 handsets by the end of June 2001. FOMA successfully launched in October 2001 providing mobile telecommunications coverage to Tokyo and Yokohama.〔 Initially - as the first full-scale 3G service in the world〔(NTT Docomo Case Study ), Picsel〕 - FOMA handsets were of experimental character targeting early adopters, and were big, had poor battery life and the network covered the center of Japan's largest towns only. For the first 1–2 years, FOMA was essentially an experimental service for early adopters - mainly communication industry professionals. As NTT DoCoMo did not wait for the finalisation of the 3G Release 99 specification, their network was initially incompatible with UMTS. However, in 2004 NTT DoCoMo performed wide-scale upgrades on its network, bringing it into compliance with the specification and enabling 100% compatibility with UMTS handsets, including incoming and outgoing roaming. Around March 2004, FOMA achieved the breakthrough into mass sales, and sales soared. As of September 29, 2007, FOMA had over 40 million subscribers. 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「Freedom of Mobile Multimedia Access」の詳細全文を読む スポンサード リンク
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