03-01-2011, 04:48 PM
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INTRODUCTION
4G (also known as Beyond 3G), an abbreviation for Fourth-Generation, is a term used to describe the next complete evolution in wireless communications.
It will be able to provide a comprehensive IP solution where voice, data and streamed multimedia .
It can be given to users on an "Anytime, Anywhere" basis, and at higher data rates than previous generations.
As the second generation was a total replacement of the first generation networks and handsets.
the third generation was a total replacement of second generation networks and handsets.
The fourth generation cannot be an incremental evolution of current 3G technologies, but rather the total replacement of the current 3G networks .
There is no formal definition for what 4G is; however, there are certain objectives that are projected for 4G .
These objectives include: that 4G will be a fully IP-based integrated system. 4G will be capable of providing between 100 Mbit/s and 1 Gbit/s speeds both indoors and outdoors, with premium quality and high security.
Fourth Generation (4G) Wireless Networks are being developed to further enhance the mobile user experiences through higher speed radio access and increased quality of service (QoS) .
HISTORY OF 4G WIRELESS
Wireless System Evolution:
First generation: Almost all of the systems from this generation were analog systems where voice was considered to be the main traffic.
Second generation: All the standards belonging to this generation are commercial centric and they are digital in form. Around 60% of the current market is dominated by European standards.
Third generation: To meet the growing demands in network capacity, rates required for high speed data transfer and multimedia applications, 3G standards started evolving .
The systems in this standard are essentially a linear enhancement of 2G systems .
Currently, transition is happening from 2G to 3G systems. As a part of this transition, numerous technologies are being standardized.
2.75G:
EDGE/EGPRS
CDMA2000 (1xRTT)
3G:
UMTS (W-CDMA)
CDMA2000 (1xEV-DO/IS-856)
WiMax
FEATURES OF 4G WIRELESS SYSTEMS
The following are some possible features of the 4G systems :
1. Support interactive multimedia, voice, video, wireless internet and other broadband services.
2. High speed, high capacity and low cost per bit.
3. Global mobility, service portability, scalable mobile networks.
4. Seamless switching, variety of services based on Quality of Service (QoS) requirements
