Those who can use LTE/WiMAX, and those that can't use HSPA+.

That's increasingly the reality of at least two major American carriers' scheme to rebrand an extension to 3G wireless transmission technology to 4G, while failing to meet the standards originally set for 4G.

I.  The Origins of 4G

The origins of the mess began in late 2009, when T-Mobile began upgrading its network to support HSPA+.  That was a noble enough objective, but then in September 2010, T-Mobile announced a new Android handset, the T-Mobile G2 (HTC Desire Z), which supports HSPA+, an advanced 3G technology.  T-Mobile began to make a quiet claim, stating that the 3G phone offered "4G-like" speeds.  Those claims were followed by T-Mobile's much noisier release of the T-Mobile MyTouch 4G (HTC Glacier).  All of a sudden T-Mobile was claiming in ads that it had a 4G network.

Meanwhile Sprint and Verizon -- who were deploying true 4G networks by the original definition of the term -- sat by scratching their heads.  And AT&T, whom hadn't gotten around to 4G yet, but had perhaps America's best 3G data network (their voice network wasn't so hot), reacted in a much more critical manner blasting T-Mobile for making its claims.

A company spokesperson rebuked T-Mobile, stating, "I think that companies need to be careful that they're not misleading customers by labeling HSPA+ as a 4G technology.  We aren't labeling those technologies as 4G."

At the 2011 Consumer Electronics Show, expectations for AT&T's keynote were high.  The company was rumored to be launching 4G Android smartphones.

But in a cruel twist it abandoned its previous stand and released three models with "4G" in their title, which in fact could only support HSPA+.  The company added it would also be deploying LTE products shortly.

Why should customers care?

II.  "4G" vs. "3G" -- By the Numbers

Well, LTE (which Verizon is using) in its current form supports 100 Mbit/s downloads and WiMAX offers even more impressive 128 Mbit/s downloads.  HSPA+ offers only about half that, with 56 Mbit/s.  And the gap grows, when you consider that fixed versions of LTE and WiMAX are expected to deliver speeds of up to 1 Gbit/s.  

The story is similar when it comes to upload speeds.  LTE offers 50 Mbit/s, WiMAX offers 56 Mbit/s.  HSPA+ only offers 22 Mbit/s.

Now the proponents of HSPA+ may point out that the technology offers an order of magnitude (at least) increase in speed over traditional 3G.  Thus it's closer to 4G than 3G in a way.  But it's still not what was originally promised with 4G.

And the story is even more complex than that.  LTE and WiMAX were designed with core objectives of improving power efficiency and wireless spectrum usage efficiency.  By contrast HSPA+ operates much more like traditional HSPA/CDMA/etc. 3G technology.  This is showcased by the fact that HSPA+ can be implemented via a firmware update; whereas LTE and WiMAX require physical modification to antennas and towers.  

Despite all of this, AT&T and T-Mobile are in the right, according to a major industry council.  The International Telecommunication Union (ITU) in December announced that it was defining 4G as, "It is recognized that [4G], while undefined, may also be applied to the forerunners of these technologies, LTE and WiMAX, and to other evolved 3G technologies providing a substantial level of improvement in performance and capabilities with respect to the initial third generation systems now deployed."

Unlike past definitions, this one opened the door for HSPA+ a slower iterative advance, to be relabeled "4G".

III.  But Aren't LTE/WiMAX Failing to Deliver Promised Speeds?

A final thing worth noting is that LTE and WiMAX networks still have a long ways to go to live up to their promised speed numbers.  Sprint's WiMAX reportedly is putting up 3-6 Mbps up and 10 Mbps down.  Testing of Verizon's LTE network showed it to be pulling a similar 12 Mbps down and 6 Mbps up.  Outside the U.S., Norway, Sweden, Ireland, and South Korea are all trying to deploy 4G networks as well with varying results.  Norway and Sweden's TeliaSonera 4G LTE network, for example, was shown pulling 43 Mbps down, but can only push 6 Mbps up, similar to Sprint and Verizon.

Still, these networks are generally regarded as pre-release 4G and should be able to be refined to deliver fully on the promised 4G speeds, unlike HSPA+, which is unlikely to deliver equivalent speeds.  

Furthermore, HSPA+ has yet to live up to its own speed claims as well.  Recent tests showed T-Mobile's HSPA+ network to be pulling down around 3 Mbps on average and pushing up about 1 Mbps on average, slower than current 4G implementations, even.  Like the true 4G networks, the HSPA+ networks will likely eventually work up to their promised speeds, but at the end of the day, they're working towards a final goal that provides less to the consumer.

IV. Conclusions

Public relations and corporate management can call HSPA+ "4G", but AT&T's spokesperson had it right in the first place -- companies labeling HSPA+ as 4G risk "misleading customers".  And the net result is that customers will be getting less than was originally promised.

Fortunately the industry seems divided on this issue.  Even AT&T is straddling the fence, promising to deploy LTE, while reversing its stance on HSPA+ and rebranding it "4G".  At the end of the day its up to customers to guide the market by recognizing true 4G -- LTE and WiMAX -- from the imposters, and using their buying power to leave those who erroneously peddle HSPA+ as "4G" in the dust.