Today is the day of internet. In most field wireless system is very widely used.Currently a number of technologies like1G,2G,2.5G,3G etc A new technology is introduced which is called as 4G technology.
Fourth generation wireless system is a packet switched wireless system with wide area coverage and high throughput. It is designed to be cost effective and to provide high spectral efficiency. Data rate of 20mbps is employed. Mobile speed will be up to200km/hr.The high performance is achieved by the use of long term channel in both time termchannel in both time and frequency ,scheduling among users and smart antennas combined with adaptive modulation and power control. Frequency band is 2-8 GHz. it gives the ability for world wide roaming to access cell anywhere.It uses OFDM (ortogonal frequency divisional multiplexing) and Ultra Wide Radio Band(UWB), and Millimeter wireless and smart antenna.4G uses a multi network functional device software which is very helpful for multiple user.
-support for interactive multimedia, voice, streaming video, Internet, and other broadband services -IP based mobile system-High speed, high capacity, and low cost per bit. -global access, service portability, and scalable mobile services -Seamless switching and a variety of Quality of
-Better spectral efficiency. Service driven services.
- Better scheduling and call admission control techniques
-Expensive and hard to implement
-bettery usage is more
-needs complex hardware
There is a need for next generation of wireless technology i.e. 4G which will be a platform for seamless technology providing widespread coverage ,band width and power consumption with higher data rates . .