Scott will have to say what he can about how it works. I have no idea.
Part of the whole 4G issue is that 4G does not yet officially exist.
The ITU, part of the UN, is in charge of defining what 4G will be. The term they are using is IMT-ADVanced. IMT-2000 was 3G and is still being expanded upon with the first version of WiMAX aka IEEE802.16e being placed on the approved IMT-2000 technology list earlier this year. IEEE802.16m aka WiMAX2.0 and something called LTE are the early contendors for what will become IMT-ADV sometime in 2010.
The process to define IMT-ADV started about 8 years ago. I was one of the first people to start working on it. IF you ever hear them refer to the IMT-ADV "VAN" diagram, that was me and three other people spending a weekend in Sweden coming up with that definition. It is the single picture of what data rates IMT-ADV must be able to support.
So the question is why build now? Well because it takes about a decade to do a generational built out. 3G has been rolling out since the late 1990's and likely will see at least another 10 years of rollouts and upgrades so that the carriers can get their ROI for the big bucks they spent on acquiring 3G spectrum.
Many countries in Europe sold spectrum at auction but tied it to 3G deployments. If the carrier does not deploy 3G they loose the spectrum. Europe is not alone in this either, but for once the US has got the upper hand in 3G spectrum. Usually the US does dumb spectrum stuff that hurts us when compared to the rest of the globe.
3G has equipment, the cost of equipment is low compared to the WiMAX and the LTE stuff and has capabilities that are mature. Also 3G will work in multi-mode with 2G GSM voice. So there is almost ubiquitous coverage.
Lets also talk about cell site costs.
A base station from a cellular infrastructure equipment vendor costs anywhere from $50k to $100k. Then the carrier must add data lines, battery back up, antenna tower and antennas plus the really high cost items such as the real estate itself. Real estate is the single biggest cost. Due to zoning, NIMBY, and other issues. When you add it all together the cost per cellsite is about $1,000,000!!! Equipment is only about 15% of that cost. So doing an upgrade is not all that cost intensive as long as you can reuse the real estate.
In the US the next highest cost is not the infrastructure equipment but the actual handsets.
In the US carriers still subsidized the handset. That is why you can get a $300 handset for $19.95. The carrier will hold you to a contract to earn back that money from you for the handset. The largest captial expense in a cellular system is the subscriber equipment.
couldn't even drink my bloody mary mix.
