The 1G or First Generation, was an analog system and was invented in the AT&T’S lab in USA in the early 1970’s.1G had two major improvement, this was the invention of microprocessor, and the digital transform of the control link between the phone and the cell site.
1G Poor voice quality Poor battery life Large phone size No security Frequent call drops
2Gphones using global system for mobile communication(GSM) were firstly used in the early 1990s in Europe.GSM provides voice and limited data services , and used digital modulation for improved audio quality.
2G Unable to handle complex data such as videos. Do not support high data rates. Poor signals in less populas areas.
An interim stage that is taken place between 2G and 3G is 2.5G. Itis basically an enhancement of two major technologies to provide increased capacity and to increase higher bit rate.
The3G technology adds multimedia facilities to 2G phones by allowing video, audio graphics. The main idea behind 3G is that to have a single network instead of different types adopted in US, Europe and Asia.
3Go High bandwidth requiredo High spectrum licensing fees.o Huge capital
A 4G system provides mobile ultra-broadband internet access , for example to laptops with USB wireless modems ,to smart phones also. Application adaptability and being highly dynamic are the key features of 4G service of interest to users.
Dueto substantial growth in number of subscribers. Dueto massive demand of new services like data ,audio ,image or video.
Faster and more reliable Multi-standard wireless system Smooth handover across wide network Scalable channel bandwidth 100+Mhz
4GA key challenge facing deployment of 4G technology is how to make the network architectures compatible with each other. Cost is another factor that could hamper the progress of 4G technology. The operating area ,rural areas and many buildings in metropolitan areas are not being served well by existing wireless network.
A major issue in 4G system is to make high bit rates available in larger portion of the cell, especially to users in an exposed position in between several base stations. 5G(5th generation mobile network)is a name used in some research papers and projects to denote the next major phase of mobile telecommunications standard beyond the upcoming 4G standard.