LTE, what it is, and why it might undo the damage AT&T hath wrought.

So having described the history of the whole mobile phone "generation" thing in my previous post, what is "LTE"?

Well, to recap:

• The first and second generation mobile networks were primarily voice based, with the second generation being intended to fix the problems of the first.
• The third and fourth generation mobile networks are data and voice based, with the fourth generation being intended to fix the problems of the third.

There's some overlap. Many "2G" standards supported data, but the real, usable, data is in 3G.

So, with that in mind, what's LTE and why is it a really good thing?

A brief summary of LTE

LTE is the third version of the GSM mobile communications standard. The first version is generally just called GSM, and introduced the basic concepts of a mobile phone system, notably calls (voice and data), messaging, and something called "personal mobility" - essentially the ability for a user to separate their account from their device, allowing them to switch devices at will. In GSM this is achieved using a SIM card.

The second version, called 3GSM or UMTS (often, misleadingly, known as W-CDMA, HSDPA, HSPA, or HSPA+ - these are technologies used by UMTS) added something called "packet switched data" to GSM. While there were extensions to the first version, called GPRS and EDGE, the second version of GSM was a redesign that integrated data into the heart of the system and was designed to support high data rates.

The third version of GSM is called LTE. LTE is another redesign. This time LTE itself is data only. Voice services run over the Internet, and LTE is used as your Internet connection. You'll not notice this of course, to you an LTE phone will work just as any other phone, but the fact voice works this way leads to some general improvements in how things work.

Now, in theory, by separating the services from the network they run over, and using the Internet as the network opens up all kinds of possibilities. The biggest is that you're no longer dependent on one carrier to ensure you have coverage - use wifi if you can't get a cellular signal, for example. Carriers and phone manufacturers alike can also benefit from this architecture - it's easy to swap in and out other technologies to provide an Internet connection.

In practice, this isn't going to happen right away. Indeed, many operators are specifically avoiding using LTE for voice, seeing the technology as not quite ready for that yet.

What LTE gives you however is the following:

• You choose the hardware - LTE, like UMTS and GSM 2G before it, uses SIM cards
• The technology is, well, it's not future proof (nothing is), but it's extremely scalable, so it'll be some years before it's in need of replacement, unlike UMTS
• Very high bitrates
• Much higher reliability than UMTS
• In theory, believe it or not, cheaper communications in the long term!
  

Where we're at in the US, and how it relates to the end of T-Mobile

A number of carriers are rolling out LTE. The two biggest are Verizon Wireless and AT&T. A smaller company, MetroPCS, has also started rolling out its LTE network, and others are likely to follow.

The two major companies bucking the trend are Sprint PCS and T-Mobile T-Mobile wants LTE, but doesn't have the spectrum. If the government approves AT&T's proposal to close down T-Mobile, then that ends that issue. Sprint PCS wanted to start early, and so has heavily invested in WiMAX, LTE's only real competitor. Sprint have said publicly they'll switch over to LTE if it becomes necessary, but in all honesty, more than any other standards, the "All IP" nature of both networks makes it possible for the two to co-exist and even interoperate to a certain extent.

But here's the thing: Verizon Wireless is switching from CDMA2000, a system they favored because of the control it gave them over their customers, to LTE. MetroPCS is switching from CDMA2000, a system they favored because of the control it gave them over their customers, to LTE. AT&T... well, they're already a GSM shop, but they're not switching away.

In being the overwhelming choice of carriers, and being part of the only open mobile phone standard family, LTE may well undo some of the damage we're seeing from AT&T's plan to destroy T-Mobile. It should be easier than ever before for third parties to independently develop hardware for LTE networks, without needing the approval of anyone other than the people who plan to use the systems (and, of course, the FCC...) Had this not happened, had AT&T been the sole GSM provider in the US, I think things would be beyond terrible for the mobile phone industry. But the move to LTE (and hence GSM based networks) means that's not going to happen, AT&T will need to compete, and it'll have difficulty imposing its will on phone manufacturers.

We'll have to see. The next generation networks will be under the thumb of providers with no history of supporting innovation and respecting their customers, but the technology itself might change them for the better.