2G Sim Card

2G refers to the second generation of mobile telecommunication technologies, which include standards like GPRS and EDGE that send mobile data at rates measured in kilobits per second (Kbps). In other words, 2nd generation of mobile networks is better equipped to deliver online content, as well as multimedia like videos and images, to users as quickly as possible. 2G, first introduced in 1992, is the second-generation of cellular telephone technology and the first to use digital encryption of conversations. 2G Sim Card were the first to offer data services and SMS text messaging, but their data transfer rates are lower than those of their successors. 2G cellular networks were commercially launched on the GSM standard in Finland. 2G technologies enabled the various networks to provide services such as text messages, picture messages, and MMS (multimedia messages). After 2G was launched, the previous mobile wireless network systems were retroactively dubbed 1G. While radio signals on 1G networks are analog, radio signals on 2G networks are digital. Both systems use digital signaling to connect the radio towers (which listen to the devices) to the rest of the mobile system. With General Packet Radio Service (GPRS), 2G offers a theoretical maximum transfer speed of 40. GSM is a second generation or 2G mobile phone system. Originally introduced in 1991, it is still used for many voice calls and some low data rate services that require its use.The acronym for GSM originally meant Groupe Speciale Mobile, but this changed to Global System for Mobile Communications as the system spread on a global basis.The use of GSM grew beyond all the original expectations. Initially it had been conceived as a European system, but its use spread globally and by 2004 there were over a billion subscriptions – a milestone achievement as it had taken over 100 years for landlines to reach this point. The GSM system was designed as a second generation (2G) cellular phone technology. One of the basic aims was to provide a system that would enable greater capacity to be achieved than the previous first generation analogue systems. GSM achieved this by using a digital TDMA (time division multiple access approach).By adopting this technique more users could be accommodated within the available bandwidth. In addition to this, ciphering of the digitally encoded speech was adopted to retain privacy. Using the earlier analogue cellular technologies it was possible for anyone with a scanner receiver to listen to calls and a number of famous personalities had been “eavesdropped” with embarrassing consequences. Speech or voice calls are obviously the primary function for the GSM cellular system. To achieve this the speech is digitally encoded and later decoded using a vocoder. A variety of vocoders are available for use, being aimed at different scenarios.In addition to the voice services, GSM cellular technology supports a variety of other data services. Although their performance is nowhere near the level of those provided by 3G, they are nevertheless still important and useful. A variety of data services are supported with user data rates up to 9.6 kbps. Services including Group 3 facsimile, videotext and teletex can be supported.