A friend of mine of Facebook last night excitedly reported that his iPhone 4S had been "upgraded" to LTE because the icon in the upper bar of the phone had been changed from "3G" to "4G." I had to give him the sad, sad news that actually, no, you still have the same HSPA+ connection that you've always had on your iPhone. The difference is that, well, AT&T wants to call HSPA+ 4G instead of 3G.
For those of you who aren't intimately familiar with the absurd technical jargon of mobile technology, this may be confusing. So let's put it like this: The terms "3G" and "4G" are largely used for marketing purposes and should generally be disregarded if you want to know how fast your phone's data connection is. Instead, you should look to see what underlying technology your device uses to connect to the Web.
So let's take AT&T as an example. Most of its network today is HSPA+ (a.k.a., a significantly faster version of the "3G" High Speed Packet Access technology). PC World did a pretty thorough test of HSPA+ networks such as T-Mobile and AT&T last year and typically found they delivered download speeds between 2Mbps and 3Mbps, depending on what city you live in.
However, AT&T has also been deploying another technology across its network over the past year called LTE (Long Term Evolution) that delivers much higher speeds than HSPA+. PC World found last year that Verizon's LTE network, for instance, delivered average download speeds of at least 5Mbps and usually exceeded 6.5Mbps. Wired conducted a similar test in late 2011 when both AT&T and Verizon had LTE services up and running and found again that LTE was significantly faster than HSPA+, as AT&T saw a jump from average download speeds of 2Mbps to around 13Mbps. Using my third-grade math skills, I deduce that AT&T's LTE services at the moment are more than six times faster than their HSPA+ speeds.
(For a more detailed and wonky analysis of the carriers' network technologies, see my article on breaking down the carriers' "4G" wireless spin.)
"OK," you say. "So when does my iPhone 4S get LTE?"
The answer is never because the iPhone 4S is not embedded with an LTE chipset. In fact, Apple's new iPad was the first-ever device the company rolled out with LTE connectivity. If it makes you feel better, though, this likely means that the next generation of iPhone will be LTE-ready and the "4G" icon on the top of that device's screen might actually represent an upgrade instead of mere public relations blather.