4G Networks: Where Are We At?

"4G" is the word that all users will hear - a lot - during the next 18 months as it is the latest "star" feature in the wireless carriers' arsenal. But 4G is also one of the most confusing concepts for the average consumer, and wireless carriers do send very strong and mixed (marketing) signals that created the confusion to start with. A recent study has shown that most people think that the iPhone 4 is already a 4G phone (it's not!): that's how big the problem is. For users, not understanding how 4G differs from one carrier to the next can mean getting, and being stuck with, a slower phone for the next couple of years. That's kind of a big deal, so let's explore the 4G world.

What Was 4G Supposed To Be?
Some context will help: 4G, which means 4th Generation of cellular wireless standards, has been defined in 2008 as being a 100Mbps network in a "high mobility" situation (driving...) and a 1Gbps network on a "low mobility" situation (walking...). Note that both are theoretical (speed-of-light) numbers. There are other features (like security) involved with 4G, but most consumers want to get in for the speed, so I'll stick to that. Unfortunately, none of the current "4G" network reaches anywhere near these numbers. The industry aimed for 1000Mbps (1Gbps), but we're very happy to get a real 20Mbps today.

What happened? basically, two things: 1/ it was simply too hard to reach those speeds 2/ wireless carriers wanted to market new products, and couldn't wait forever before using the term "4G".

It means that it you take "4G" as it was defined at its inception, none of the current networks should actually be called "4G". I believe that the International Telecommunication Union (ITU) has relaxed the definition of 4G... which makes things even murkier.

The wireless carriers are not using any numbers to define what 4G is. Instead they sell "4G" as a "next-generation experience", which should "feel" much faster. Note the term "feel", because while synthetic numbers are important, user perception should always superseed it.

What 4G Eventually Became
Nowadays, many wireless carriers use different technologies that they call "4G". There is Verizon has LTE, Sprint has WiMax, T-Mobile and AT&T have HSPA+, although AT&T plans to switch to LTE at some point this summer...

LTE, WiMax and HSPA+ are very different networks. In a recent past, HSPA+ was still considered as a 3.5G network. Somewhere along the way, carriers using it felt the pressure from competitors using the term "4G", and decided to promote HSPA+ to "4G" status. That was an easy upgrade...

WiMax was the first network to be called "4G" in the USA. When it was introduced it was clearly faster, with downloads speeds of 5Mbps. I have been told that a different implementation of this technology could yield much higher speed, however, I have never had the opportunity to test WiMax in Japan or Korea. Since then, HSPA+ networks have been catching up, and depending on where you try, you might get mixed results. In any case, the WiMax commercial advantage is not as strong as it used to be.

In the U.S, the only network that I would consider to be a 4G network is LTE. At this point, there is only one carrier to have a commercial deployment, but by the end of the year the two largest carriers in the USA will have LTE networks.

Are All "4G" Networks Equal?

From what you have read above, you can guess that all so-called "4G" networks aren't equal. However, the comparison is simple: LTE blows everything else out of the water. With real-world download speeds of 15-20Mbps, and upload speed far above 5MBps, LTE has no problem distancing itself from WiMax and HSPA+. In fact, in all our tests, HSPA+ feels much more "3G" than "4G". Some say that LTE networks will slow down as more users join the LTE party. This may be true, although, it is very hard to forecast what the impact will be.

For HSPA+ the real-world speed difference with 3G is small, and the "perceived" speed boost is close to none: my iPhone 4 isn't any slower than my Motorola Atrix for instance. WiMax isn't providing any silver bullets either. In short, and for the next 18months, expect LTE to be the clear winner of this 4G fight.

The first generation of LTE devices tend to consume much more power.

However fast it is, LTE isn't perfect yet: while it provides an amazing speed and response time (as tested with the Thunderbolt), the first generation of LTE devices suffer from fast battery depletion (the Droid Charge suffers from that too), which is a big problem with most mobile phone users -- except for the most hardcore power-user who are ready to charge the device as often as possible.
Conclusion

As an end- user, you should know that while HSPA+ and WiMax have been providing some progress in terms of speed, all 4G networks aren't equal. LTE is currently the king, by a good margin. Also, you should realize that the coverage in *your* area is what matters. Things can be very different from one part of the town to the next, and local construction features like metallic structures can affect reception.

In the grand scheme of things, absolute speed is not always the most important feature. Most people will try to balance out speed, battery life and plan price (customer service is very important too...). The next generation of LTE devices should largely solve this problem, and by, then non-LTE networks might also offer improved performance too, so stay tuned.

As the ultimate judge of 4G technologies, what's your take? Do you feel like having a clear understanding of the various 4G networks? What do you expect from a next-generation network?

=================================================================== Ubergizmo loves gadgets and the technologies that make the gadgets go. We are geeks to the core, but while we talk geek, we also talk electronics in a way that our grandparents can understand. We take everything into consideration from design, to user interface to practicality, pricing and competition.We make lists to help you decide what gadgets you need (or don't). And we deliver live coverage at conferences like CES, E3, Mobile World Congress, CTIA, DEMO and GDC, so our readers can feel like they are there with us. If it's cool, we are covering it. Hubert Nguyen is the co-founder and editor of Ubergizmo. He is a retired engineer who programmed special-effects demos at NVIDIA. Hubert also managed the developer education program and edited the GPU Gems 3 book. Before joining NVIDIA, Hubert was at 3dfx interactive. Prior to that, he worked on 3D-Engines in various video games.