II Generation of Cellular Phones

Cellular phones from the early 1990's are considered being second generation (2G) and they were able to work on mobile phone systems such as GSM, IS-136 (TDMA) and IS-95 (CDMA). Digital mobile phone networks were in use in the United States in 1990 and in Europe by 1991. 2G mobile phones use digital circuit switched transmissions. This ultimately enabled quicker network signaling, lowering the amount of dropped calls and increasing call quality. As 2G digital networks were online, most of the time, they replaced analog network frequencies, effectively making them obsolete. Phones based on 2G technology were much smaller than the brick telephones of the mid to late 80's. Most 2G cellular phones were usually in the range of 100 to 200 grams, plus they were hand held devices that were truly portable without the need for a large battery. Advances in battery technology, as well as computer chip technology also helped to make 2G cell phones much smaller than their predecessors. With these innovations, cell phone usage soared.