|
3G was relatively slow to be adopted globally. In some instances, 3G networks do not use the same radio frequencies as 2G so mobile operators must build entirely new networks and license entirely new frequencies, especially so to achieve high data transmission rates. Other delays were due to the expenses of upgrading transmission hardware, especially for UMTS, whose deployment required the replacement of most broadcast towers. Due to these issues and difficulties with deployment, many carriers were not able to or delayed acquisition of these updated capabilities. In December 2007, 190 3G networks were operating in 40 countries and 154 HSDPA networks were operating in 71 countries, according to the Global Mobile Suppliers Association (GSA). In Asia, Europe, Canada and the USA, telecommunication companies use W-CDMA technology with the support of around 100 terminal designs to operate 3G mobile networks. Roll-out of 3G networks was delayed in some countries by the enormous costs of additional spectrum licensing fees. (See Telecoms crash.) The license fees in some European countries were particularly high, bolstered by government auctions of a limited number of licenses and sealed bid auctions, and initial excitement over 3G's potential. The 3G standard is perhaps well known because of a massive expansion of the mobile communications market post-2G and advances of the consumer mophone. An especially notable development during this time is the smartphone (for example, the iPhone, and the Android family), combining the abilities of a PDA with a mobile phone, leading to widespread demand for mobile internet connectivity. 3G has also introduced the term "mobile broadband" because its speed and capability make it a viable alternative for internet browsing, and USB Modems connecting to 3G networks are becoming increasingly common. ==Africa== The first African use of 3G technology was a 3G video call made in Johannesburg on the Vodacom network in November 2004. The first commercial launch was by Emtel-ltd in Mauritius in 2004. In late March 2006, a 3G service was provided by the new company Wana in Morocco. In May 2007, Safaricom launched 3G services in Kenya while later that year Vodacom Tanzania also started providing services. In February 2012 Bharti Airtel Launched a 3.75G Network in selected cities in Kenya with a countrywide rollout planned for later in the year. In Egypt, Mobinil launched the service in 2008 and in Somaliland, Telesom started first 3G services on 3 July 2011, to both prepaid and postpaid subscription customers. Telecommunication networks in Nigeria like Globacom, Etisalat, Airtel and MTN provide 3G services to their numerous customers. 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「3G adoption」の詳細全文を読む スポンサード リンク
|