Explanation of 3G

3G, 3G, 3G – you can’t turn on the TV or drive past a billboard or bus stop advertisement without coming across these letters. But for all the trumpeting of 3G capability that cellular networks do, few of us know just exactly what 3G means. Except that it’s good, right? After all, it stands for third generation, making it obviously better than 2G, the second generation.

Those assumptions are true in part and not as true in other ways. Figuring out the implications of 3G networks and 3G smartphones requires understanding of a few basic technical details about 3G. Read on.

The Official Word on 3G

3G is a term defined by the International Telecommunication Union (ITU), but even as the ITU admits, the term is broadly applied to numerous technologies that marketers want to convey as “revolutionary.” To understand how the ITU defines 3G, it’s important to know a bit about its predecessors.

1G vs 2G

1G refers to the first generation of cellular service. That would be the gigantic, brick-like phones made popular by the likes of Zack Morris on Saved by the Bell. These phones used analog radio technology to transmit voice only.

When cell phone technology shifted to digital, the technology became known as 2G. This transition was somewhat like the switch from analog TV receivers to digital TV transmissions – the hardware had to change, but the quality and coverage received an enormous boost. So, the differences between1G and 2G is pretty clear: 1g is analog (not digital) and 2G is digital.

2.5G

Within the 2G era, there have been a series of mini-revolutions which have introduced industry parlance such as 2.5G and 2.75G. Being somewhat of a catch all gray area between 2G and 3G, these fractional generations are especially hard to define. But as far as evolution goes, you could consider them missing links – the proverbial fish with legs.

2.5G is recognized with the introduction of General Packet Radio Service (GPRS). This gave a speed boost for capable devices, but more importantly, allowed support for Wireless Application Protocol (WAP) access, Multimedia Messaging Service (MMS) and email and WWW access. GPRS uses packet switching, which is the same mechanism used by TCP/IP connections for computers and laptops. If you have a phone with Push-To-Talk, instant messaging clients, web-enabled applications and the ability to send pictures and videos via text message, then your phone is 2.5G.

3G

While the divide between 1G and 2G is easy to identify – analog vs. digital – what separates 2G and 3G is harder to define. That’s because the ITU chose to define 3G by a standard of performance rather than technology. To further complicate matters, 3G is backwards compatible with 2G technology, meaning they can both work on the same network with the same phones (contrast it to the DTV transition and how analog receivers need converter boxes).

The ITU refers to 3G  standards as the International Mobile Telecommunications-2000 (IMT-2000). The IMT-2000 specifications include:

•    Broadcasting over the spectrum between 400 MHZ and 3GHz
•    A minimum speed of 2 megabytes per second for stationary or walking users
•    A minimum speed of 348 kilobytes per second for those in a moving vehicle

The IMT-2000 is a bit of a murky classification, since it attempts to unify all the different 3G systems into a harmonious standard in order to facilitate “global roaming” (i.e. all phones would be compatible with all networks). But so far, mobile carriers are a far cry from this goal. In fact, there are three different 3G standards within the IMT-2000 that apply to cell phones. They are:

W-CDMA – W-CDMA is used primarily in Europe and Japan and is also known as UMTS. This is an upgrade from the Global System for Mobile communications (GSM) that is the standard in Europe. Because of this, it is also known as 3GSM. In the U.S., Cingular runs a 3GSM network for its Cingular Video service.

CDMA2000 – CDMA2000 is developed by Qualcomm and is prevalent in North America. 3G CDMA2000 networks use EV-DO technology, which uses separate frequencies for voice and data (unlike GSM). Sprint and Verizon are major CDMA2000 carriers in the U.S.

TD-SCDMA¬ – This is the standard in China, which has the most mobile users in the world. However, TD-SCDMA has less coverage in other areas.

So what about EDGE?

You may have noticed that the EDGE network wasn’t mentioned in the 3G rundown. That’s because for the most part, EDGE technology is considered 2.5G or 2.75G. EDGE stands for Enhanced Data rates for GSM Evolution and is, as the name suggests, an extension of GSM. While many carriers do define EDGE as 3G, its speeds are rated at a maximum of 1 megabyte per second, making it somewhat slower than other 3G standards.

So what’s best for your phone?

As discussed, 3G phones are widely regarded as faster and more flexible than its predecessors. But there are some things to consider when choosing a 3G or 2G phone.

One is the 3G coverage in your area. While all carriers have largely uniform coverage for 2G phones, some areas may have spotty 3G coverage. Of course, 3G phones work on 2G networks, but you won’t experience the speeds you would if you were on a 3G network.

Also note that 2G phones consume considerably less battery than 3G phones. There is a significant tradeoff between speed and battery life when it comes to 3G and it’s important to consider which is more important to you.

Many phones, including the iPhone and many phones running Windows Mobile, have the option to switch off 3G and revert to 2G. This is a useful feature when you are in a low 3G coverage are or wish to preserve battery.

So, there you have it. 3G is difficult to understand – in fact, the ITU still has somewhat of an amorphous definition of it. But by understanding a little bit about the evolutions in cell phone technology, you can begin to gain a clearer picture of the significance and implications of 3G.

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Related posts:

1. Cell Phone Definitions: What is AMPS (Advanced Mobile Phone Service)?
2. An Explanation of 3G Roaming
3. Cell Phone Terminology: A Quick Overview
4. What is 3.5G Service?
5. Is 2G Cell Phone Technology Still Used?
6. Wi-Fi, an Explanation
7. Researching the Best Cell Coverage for You
8. Google Goggles: An Explanation of Augmented Reality
9. What is the Difference Between GSM and CDMA?
10. The Differences of GSM and CDMA Technology

Tags: 3G, packet swithching, push to talk

This entry was posted on Thursday, October 8th, 2009 at 2:30 pm by Bryan Bradshaw and is filed under Cell Phones. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.