As I go through my day, I am often asked questions about how cellular networks operate, how calls or mobile data connections are made. … may help some, but I’ve found it difficult to find a good primer on cellular technology. Enter Mobility 101 To help answer some of these questions, I’ve started a section on FreshlyMobile.com called Mobility 101. Mobility 101 articles will eventually cover a wide range of topics designed to provide some perspective on the technology and business of mobile communication, to explain common terms or to generally help take the mystery in how things work. … In Mobility 101 , (and indeed much of FreshlyMobile) we will often tend towards easier to understand generalizations rather than the often impenetrable (but technically accurate) technical minutia. … Cellular Tech 101 Today I would like to introduce the first in a four-part series that will take a brief look at the history, terminology, technology, and the general anatomy of cellular networks, which I call Cellular Tech 101. … The first mobile phones (you remember or have seen pictures of the big brick phone or a phone in a bag) are now generally called 1G phones. … While few people had these phones, the technology was changing rapidly and in the 1990’s we began to move into the 2nd Generation or 2G era. … With the move to digital and 2G, we found cellular companies divided into two technology camps, CDMA and GSM. … Three of the 4 major carriers in the US (AT&T, Sprint and Verizon) have been operating 3G networks for some time. T-Mobile is currently in the process of upgrading their network to 3G and is currently offering something that is often called 2.5G. 2.5G is a marketing term and it is an interim step between the 2G and 3G worlds. All the carriers took this 2.5G step as it offered faster data service than 2G, without the pain and expense of upgrading the network to support 3G. Speaking of 2.5G and 3G, you may have heard some people say that the Apple iPhone only supports EDGE and not 3G (yet). EDGE is considered a 2.5G technology and is widely deployed by AT&T and T-Mobile in the US.