1G (first generation) refers to the analog mobile telecommunications standards introduced in the late 1970s. The term was later applied retroactively to distinguish these early cellular network systems from later digital generations.
1G (first generation) refers to the analog mobile telecommunications standards introduced in the late 1970s. The term was later applied retroactively to distinguish these early cellular network systems from later digital generations.
2G refers to the second generation of cellular network technology, which were rolled out globally starting in the early 1990s. The main differentiator to previous mobile telephone systems, retrospectively dubbed 1G, is that the radio signals of 2G networks are digital rather than analog, for communication between mobile devices and base stations. In addition to voice telephony, 2G also made possible the use of data services.
The most common 2G technology has been the GSM standard, which became the first globally adopted framework for mobile communications. Other 2G technologies include cdmaOne and the now-discontinued Digital AMPS (D-AMPS/TDMA), as well as the Personal Digital Cellular (PDC) and Personal Handy-phone System (PHS) in Japan.
The Global System for Mobile Communications (GSM) is a family of standards to describe the protocols for second-generation (2G) digital cellular networks, as used by mobile devices such as mobile phones and mobile broadband modems. GSM is also a trade mark owned by the GSM Association. "GSM" may also refer to the voice codec initially used in GSM.
2G networks developed as a replacement for first generation (1G) analog cellular networks. The original GSM standard, which was developed by the European Telecommunications Standards Institute (ETSI), originally described a digital, circuit-switched network optimized for full duplex voice telephony, employing time division multiple access (TDMA) between stations. This expanded over time to include data communications, first by circuit-switched transport, then by packet data transport via its upgraded standards, GPRS and then EDGE. GSM exists in various versions based on the frequency bands used.