I. Cellular Generations:
Nowadays, with the development and enhancement of wireless communications networks, several standards derived from the concept of “Cellular” for various types of newer wireless systems have been arisen with a dramatic increase in the mobile technology in order to satisfy the customer needs and make their life easier by providing them with higher data rates and more mobile services with a higher spectrum efficiency . Furthermore, the cellular concept was first deployed the periods between 1960’s and 1970’s, and then it has been enhanced in the mid 1990’s to be consisted of several unimaginable mobile wireless networks in order to support the higher data traffic . The following figure 1 shows the development and evolution of various wireless communications generations starting from 1G technologies and ending with 4G technologies.
Figure 1: Wireless Communications Generations 
The first generation (1G) of mobile systems was first designed in 1970’s, and it was first implemented in 1981’s . In addition, 1G technology is relied on the analog technology by using the Advanced Mobile Phone System (AMPS) which is consist of seven-cell reuse pattern by using frequency modulation (FM), frequency division duplexing (FDD) and frequency division multiple access (FDMA) . Therefore, the analog speech signals are provided by the first generation of wireless communications systems with low data rate and insufficient data transmission between the base station and mobile user .
First Generation (1G)
Second Generation (2G)
The second generation (2G) of mobile systems was first designed in 1980’s, and it was first implemented in 1991’s due to the need to overcome the issues associated with the 1G technology such as the low data rate and insufficient data transmission due to the use of analog speech signals in 1G technology . Therefore, in the 2G technologies, the digital technology such as digital voice with a short message is used with the dependence on the digital modulation techniques such as the Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA) and Frequency Division Duplexing (FDD) . Ultimately, the 2G technology provides a high speed data communication with a high voice transmission data where the capacity of system and spectrum efficiency are increased three times greater than the first generation (1G) of mobile systems .
Despite of all above advantages of 2G technology, there is an issue associated with the second generation (2G) technology which is the low speed of internet browsing applications and electronic mail in other words e-mail services . Therefore, a new technology called “2.5G” is developed with backward compatibility with 2G standard in order to provide higher data rate transmission for internet browsing applications and e-mail services .
In the 2.5G technology, wireless application protocols (WAP) are used by which the web pages are viewed by the users in a compressed form where the number of other web compressing protocols are developed in which Ald00 is one of them . Furthermore, the general packet radio service (GPRS) can provide data rates from 56 kbit/s up to 115 kbit/s in order to be used in implementing Wireless Application Protocol (WAP) access, Multimedia Messaging Service (MMS), internet communication services such as email and World Wide Web access . Ultimately, the 2.5G technologies are used in supporting several services such as SMS, WAP, MMS, mobile games, search and directory .
Third Generation (3G)
The third generation (3G) of mobile systems was first designed in 1990’s, and it was first implemented in 2001 . Moreover, 3G technologies provides backward compatibility for 2G and 2.5G in order to get a higher speed internet access with different types of browsing applications and services such as video conferencing that makes multiple called parties to be able to communicate face to face at a long distance . Furthermore, the 3G technologies can also provide other services such as multimedia services, gaming services and very high data rate . However, there is only one problem with 3G technology which is the low speed of Internet browsing.
Fourth Generation (4G)
The fourth generation (4G) of mobile systems was first designed in 2000, and it was first implemented in 2010 . The main purpose of 4G technologies is to overcome the problem of low speed of Internet browsing by providing an Internet access facility with a very rapid speed called “Ultra-Broadband Internet Access” .
 C. S. Patil1, R. R. Karhe & M. A. Aher, Review on Generations in Mobile Cellular Technology, International Journal of Emerging Technology and Advanced Engineering, 2012. C. S. Patil1, R. R. Karhe & M. A. Aher, Review on Generations in Mobile Cellular Technology, International Journal of Emerging Technology and Advanced Engineering, 2012.
 M. Bhalla & A. Bhalla, Generations of Mobile Wireless Technology: A Survey, International Journal of Computer Applications (0975 – 8887) Volume 5– No.4, August 2010.