4G stands for the fourth generation of cellular wireless standards. The 4G system was originally envisioned by the Defense Advanced Research Projects Agency (DARPA). 4G is described as MAGIC — Mobile multimedia, Anytime anywhere, Global mobility support, Integrated wireless solution, and Customized personal service.
Cellular systems such as 4G allow seamless mobility; thus a file transfer is not interrupted in case a terminal moves from one cell (one base station coverage area) to another, but handover is carried out. The terminal also keeps the same IP address while moving, meaning that a mobile server is reachable as long as it is within the coverage area of any server. In 4G systems this mobility is provided by the mobile IP protocol, part of IP version 6, while in earlier cellular generations it was only provided by physical layer and datalink layer protocols. In addition to seamless mobility, 4G provides flexible interoperability of the various kinds of existing wireless networks, such as satellite, cellular wirelss, WLAN, PAN and systems for acessing fixed wireless networks.
While maintaining seamless mobility, 4G will offer very high data rates with expectations of 100 Mbit/s wireless service. The increased bandwidth and higher data transmission rates will allow 4G users the ability to utilize high definition video and the video conferencing features of mobile devices attached to a 4G network. The 4G wireless system is expected to provide a comprehensive IP solution where multimedia applications and services can be delivered to the user on an ‘Anytime, Anywhere’ basis with a satisfactory high data rate, premium quality and high security.
Some key features (primarily from users’ points of view) of 4G mobile networks are as follows:
- High usability: anytime, anywhere, and with any technology
- Support for multimedia services at low transmission cost
- Integrated services