Mobile phones function with the use of mobile networks or cellular networks. The networks are composed of several exchanges or cell sites that are strategically distributed over a large location and they are interconnected through a base station or a central exchange. The cell sites enable the portable receivers such as pagers and mobile phones to communicate with each other. The base station provides network coverage that is used for communication. The networks run with the use of wireless communications technology. However, in the recent years, many improvements have been made to the cellular networks and due to these improvements, the designs and features of mobiles have also improved. From voice to data transmission, the capabilities of cellular networks have come a long way.
Compared to first generation networks which use analog radio signals, the second generation wireless networks use digital radio signals. With the introduction of digital cellular systems, mobile phone conversations became encrypted and more secured. The sound quality had also improved significantly. Whereas, 1G network offered only voice calls, the 2G networks introduced data services for mobiles. Among the first data services offered were SMS text messages, MMS multi-media messages and picture messages. The first commercial cellular networks were launched in 1991 and were based on GSM digital wireless network technology standards. Today, GSM is the standard protocol used in many cellular networks worldwide. Other wireless interface protocols used are D-AMPS and CDMAOne.
The third generation networks use wireless network technology that is compliant with the IMT-2000 or International Mobile Telecommunications-2000 standards. The 3G networks provide faster transfer rate of information which enable better mobile telecommunications. The early versions of 3G networks had data transfer rates of 200 Kbits/s. The enhanced versions have data transfer rates of at least 384 Kbits/s. The enhanced networks provide additional services for mobiles such as mobile TV, video calls, fixed wireless internet access and mobile internet access. The earliest versions of 3G were commercially launched in 1998. Aside from IMT-2000, there are other 3G wireless network technologies such as UMTS, TDD and Arib WCDMA that are being used worldwide.
The fourth generation networks are based on IMT Advanced standards that were set by the International Telecommunications Union. The 4G networks are required to have data transfer rates of 100Mbps. The enhanced networks provide better mobile internet access, video conferencing, gaming services, cloud computing and HD mobile TV. Mobile Wimax and Long Term Evolution (LTE) were the first 4G versions. These wireless network technologies were launched in 2008. However, there had been debates whether these technologies should be considered true 4G. There were claims that they only offered speed of up to 30 Mbps which was far from the IMT-Advanced standards. Nonetheless, these technologies are far better than their predecessors.