电子信息类专业英语Unit_20_3G教材教学课件.pptVIP

;Text　　With each generation of technology, the services which can deployed on them becomes more and more wide ranging and truly limited only by imagination. The next generation of broadband wireless communication, based on Third Generation or“3G”technology, will change our lives forever.;What is 3G?　　The mobile communications industry has evolved in three stages: analogue, digital and multimedia. Three generations of mobile phones have emerged so far, each successive generation more reliable and flexible than the last: You could only easily use analogue cellular to make voice calls, and typically only in any one country. Digital mobile phone systems added fax, data and messaging capabilities as well as voice telephone service in many countries. Multimedia services add high speed data transfer to mobile devices, allowing new video, audio and other applications through mobile phones—allowing music and;television and the Internet to be accessed through a mobile terminal. The Third Generation (3G) is the mobile multimedia based on CDMA technology. 　　A new radio communications technology that will provide high-speed mobile access to Internet-based services. It will enhance and extend mobility in many areas of our lives. We’ll expect high-speed access to the Internet, entertainment, information and electronic commerce(e-commerce) services wherever we are—not just at our desktop computers, home PCs or television sets.;　　In a 3G world, users won’t always need to“dial up”to retrieve email, multimedia attachments and other data. It will simply be downloaded to their mobile devices as soon as it is sent or requested.　　The shift to 3G services is also causing a revolution in the underlying telecommunications system as phone companies embrace the Internet and further integrate wireless and traditional fixed-wire networks. This will change the way we think about telecommunication.;　　3G Features　　3G has the following features:　　Packet everywhere　　With Third Generation(3G),