2G is the second generation of narrowband mobile communication or cellular network technology, with a top data transfer speed of 14.4 kbps; realistic speeds max at 9.6 kbps. 2G stands for “second generation”, with “2” denoting “second” and “G” standing for “generation”. The technology succeeded 1G and unlike 1G, 2G was based on digital signals. General Packet Radio Service (GPRS) and Enhanced Data rates for GSM Evolution (EDGE) were enhanced 2G technologies, unofficially called 2.5G and 2.75G respectively. The maximum theoretical data transfer speed on GPRS is 115 kbps, and 473 kbps on EDGE.
First launched in Finland in 1991, 2G offered services such as calling, SMS (text messaging), MMS (picture messaging), and email. 1G only restricted users to making phone calls. 2G made accessing the web on mobile devices possible, but the web surfing experience was still nowhere close to satisfactory. Generally, the name “2G” is synonymous with GSM, TDMA and CDMA networks.
There are primarily two different 2G technologies to transmit and decode phone calls: Code Division Multiple Access (CDMA) and Time Division Multiple Access (TDMA). Global System for Mobile communication or Mobiles (GSM) is based on TDMA. GSM supports both data and voice services.
GSM is the most widely used 2G technology, and its frequency spectrum is 900 megahertz (MHz) and 1800 MHz. CDMA is GSM’s counterpart and uses a 2G technology different than GSM. Its frequency spectrum is 800 MHz and 1900 MHz. SIM slots that support CDMA cannot be used with a GSM device. When 2G was first launched in 1991, it was based on the GSM standard. In America, 2G services are called Personal Communications Service (PCS).
Improvements Over 1G
As aforementioned, 2G transmitted signals digitally, which meant a significant improvement in call quality. 2G also enabled global connectivity since 2G spectrum had much better penetration levels, meaning calls could be made beyond countries. The digital signals also paved way for improved mobile phone battery life between charges as the low-powered 2G radio signals needed less battery juice. This also made smaller mobile phone batteries feasible, resulting in 2G-enabled phones being much more compact than 1G phones could ever be. And most importantly, 2G connections were much more secure, meaning there was almost zero eavesdropping.
Call drops are fairly common on 2G connections if the signal is weak. 1G, on the other hand, may deteriorate the quality of the call, but would seldom drop the conversation. 2G is almost obsolete in the world of smartphones, thanks to its slow data transfer speeds. Video calling, watching videos online, etc. are not practical on a 2G connection.