The second generation of telephone (2G) technologies is based on GSM technology or, in free translation, the global system for mobile communications, launched in the year 1991.
The 2G network allows for a much greater penetration intensity. 2G technologies have enabled the various mobile phone networks to provide services such as text messaging, picture messaging and multimedia messaging (MMS). It is a more efficient technology and has sufficient security for the sender and receiver. All messages are digitally encrypted. This digital coding allows data transfer in such a way that only the intended recipient can receive and read.
Second generation technologies are time division multiple access (TDMA) or code division multiple access (CDMA). TDMA makes it possible to divide the signal at intervals of time. CDMA assigns each user a special code to communicate through a physical multiplex channel. Different TDMA technologies are GSM, PDC, iDEN, IS-136. For CDMA, the technology is IS-95. GSM (Global System for Mobile Communications) is the most admired standard of all mobile technologies. Although this technology originates in Europe, it is used in more than 212 countries worldwide. GSM technology was the first to help establish international roaming. This allowed mobile subscribers to use their mobile phone connections in several countries around the world by relying on digital signals, unlike 1G technologies, which were used to transfer analog signals. GSM technology has enabled users to use short message services (SMS) for any mobile network at any time. SMS is an inexpensive and easy way to send a message to someone other than a voice or conference call. This technology is advantageous for both network operators and end users.
Digital signals require less battery power and therefore help make mobile batteries last for a long time. Digital voice coding improves clarity and reduces line noise. These digital signals were the ones that enabled the first cell phones with internet access through the 2G network.
The biggest difference between 2G and 3G technologies is the speed with which data travels between them. While in 3G technology data travels much faster, in 2G technology data runs much more slowly. However, the frequency that is used for 2G technology is much more comprehensive than 3G frequency, which means that fewer 2G antennas are required than 3G installed to serve the same area.