A mobile phone, also known as a cellular phone, cellphone, mobile, or handphone, is an electronic telecommunications device with the same basic capability as a conventional fixed line telephone, but which is also entirely portable and is not required to be connected with a wire to the telephone network. Most current mobile phones connect instead to the network using a wireless radio wave transmission technology. The mobile phone communicates via a network of base stations which are in turn linked to the conventional telephone network.
In addition to the standard voice function of a telephone, a mobile phone also supports many additional services such as SMS for text messaging, packet switching for access to the Internet and MMS for sending and receiving photos and video.
Some of the world's largest mobile phone manufacturers include Alcatel, Audiovox, Kyocera, Qualcomm, LG, Motorola, Nokia, Panasonic (Matsushita Electric), Philips, Sagem, Samsung, Sanyo, Siemens, SK Teletech, and Sony Ericsson.
3G (or 3-G) is short for third-generation mobile telephone technology. The services associated with 3G provide the ability to transfer both voice data (a telephone call) and non-voice data (such as downloading information, exchanging email, and instant messaging).
When it comes to marketing 3G services, video telephony has often been used as the flag-ship killer application for 3G. A kind of certain euphoria was created, which led to huge spectrum-licensing fees in many countries, especially in Europe, where spectrum auctions generated many billions of euros for the respective countries involved.
Since these spectrum licensing fees were collected many years before any income could be expected from 3G business, and since enormous investments are necessary to build the 3G networks, many telecommunication operators got into great financial difficulties, which greatly delayed 3G roll-out in all countries except Japan and Korea, where such spectrum licensing fees were avoided since priority was set on national IT infrastructure development.
The first country which introduced 3G on a large commercial scale was Japan. In 2005 about 40% of subscribers use 3G networks only, and 2G is on the way out in Japan. It is expected that during 2006 the transition from 2G to 3G will be largely completed in Japan, and upgrades to the next 3.5G stage with 3 Mbit/s data rates is underway.
The successful 3G introduction in Japan shows that video telephony is not a killer application for 3G networks after all. Actually, the real-life usage of video telephony on 3G networks is only a very very small fraction of all services. On the other hand, downloading of music finds very strong demand by customers. Music downloads were pioneered by KDDI with the EZchakuuta and the Chaku Uta Full services.