DCAWD.com

Cellular systems have evolved in four major phases or generations. The first generation, or 1G, technology was analog and transmitted voice calls only.

The second generation, or 2G, introduced digital transmissions and offered the first support for data, although the focus was still on voice calling. Second-generation phones are based on one of two standards: GSM (used by T-Mobile, AT&T, and most overseas carriers) and CDMA (used by Verizon and Sprint). In either case, average data speed on a 2G network is around 9.6 Kbps, about the same as a ’90s-era modems.

The intermediate “2.5G” level is where things get a little fuzzy. In the GSM camp, a standard called GPRS, which offered better data transmission capabilities, came to be known as 2.5G. GPRS has evolved into the EDGE networks (up to 400-kbps data speeds) still used by many phones today. As for the CDMA universe, 2.5G is referred to as 1XRTT, or just 1X. In the real world, it is known as EVDO and promises download speeds ranging from 600 kbps to 1.4 Mbps.

There’s been some debate on what constitutes 3G. Broadly speaking, 3G is defined not by the underlying technology, but by its speed: up to 2 Mbps. Verizon and Sprint’s 3G systems are referred to as EVDO, while AT&T and T-Mobile use HSDPA. A further level, known as HSDPA+ or Turbo 3G, can support download speeds of up to 14 Mbps...

The maximum theoretical data transfer with 3G technology is 2 Mbps. But in practice, you won’t get more than 500 Kbps to 1.5 Mbps, depending on your carrier, the location of the cell tower, congestion, etc.

4G ups the game.

WiMax can offer peak download data speeds of up to 6 Mbps and up to 1 Mbps for uploading data. WiMax rival LTE says it can do much better. It has peak download speeds of 100 Mbps and can support uploads at the rate of up to 50 Mbps.