These are 2nd and 3rd generation technologies used in wireless communication. Global System for mobile communication is 2G, which is the first step towards digital wireless connection over the current analog connection. In this know-how, for the first time, SIM, which stands for Subscriber Identity Module, is introduced, and more reliable and clear communication is accomplished. Presently, most of the world is covered by GSM, which stands for Global Systems Mobile. Multiple technologies are utilized.
These include TDMA, which stands for Time Division Multiple Access, and FDMA, which stands for Frequency Division Multiple Access. This technology allows many users to make calls simultaneously at any given time. 3G is the mobile standard requirement released, which is compatible with IMT, which stands for International Mobile Telecommunication.
3G specifications made way for the next-generation standard. Applications such as video calls, high-speed internet, multimedia applications, video streaming, video conferencing, and location-based services can be provided to mobile phones. The first commercial 3G phone was launched in Japan in 2001. It was here that the air interface technology, known as the multiple access technique, came into play.