The ITU sets the minimum for 4G designation: The International Telecommunication Union Radiocommunication Sector (ITU-R) has reaffirmed previous less settled criteria for what's a fourth-generation (4G) network. Current WiMax and LTE is nowhere near the cutoff point of 100 Mbps downstream for mobile and 1 Gbps downstream for fixed.
This isn't new, although this particular decision is new. I've been wondering by what logic Clearwire, AT&T, and Verizon were labeling current WiMax and first-generation LTE deployments as 4G, when they're incremental, welcome improvements over 3G. Some of it is architecture. As Stephen Lawson of IDG News Service notes, these networks were designed from day 1 for data, and are all Internet protocol (IP) from end to end. That's a huge improvement over 3G and it's a marked change.
The ITU-R doesn't do enforcement, and 4G isn't a trademark. Verizon Wireless and Clearwire told IDG's Lawson that the ITU-R move has no effect on their branding or deployment plans (nor should it on the latter).
My question for 4G deployment, of course, is that with it on track for 2014–2015 rollout, how realistic is it to come up with the channel widths necessary? It looks like the maximum speeds being discussed require extremely wide channels, like 100 MHz. That's not impossible, but no U.S. carrier has 100 MHz in a chunk that it materialize. The FCC white-spaces rulemaking frees up a bunch of 6 MHz pieces, and that's the last major realignment after DTV 700 MHz spectrum that I'm aware of.
The definition of 4G may now be set, but the ability to roll out 4G at anything like the minimum speeds promised seems highly problematic even in five years.