4:00 PM -- I think there could be one concept that will finally be put to rest with the coming of the so-called fourth generation of long-range wireless broadband from Sprint Corp. (NYSE: S) and others -- the idea of a phone that can be used anywhere in the world.

To be honest, the "worldphone" concept appealed mostly to globe-trotting business travelers and was hobbled well before the dawn of 4G. The move to CDMA in the U.S. and South Korea in the mid-1990s pretty much broke any hope -- or fear -- of a single worldwide digital cellular standard in GSM. Not that it would have been that simple anyway. Operators worldwide use different bandwidths for the same standards, so, at the very least, users would require a frequency-agile phone.

4G, however, is about to add a few more wrinkles to the worldphone conundrum. Handset vendors are going to need to come out with multi-mode, multi-band radios just to allow early users to roam between WiMax and 3G networks in their home markets. A worldphone would need to support WiMax and CDMA and GSM on a number of different frequencies, especially since 802.16 will operate on multiple bands worldwide.

And who is to say that operators will necessarilly all choose to use WiMax as their high-speed 4G technology when the time comes? There's no guarantee of that happening. Sprint Nextel certainly made the WiMax move to get a competitive edge on larger competitors. Might not other carriers decide that another technology will give them some kind of edge as well?

All in all, I suspect that the move to 4G and wireless broadband could leave users with faster downloads but fewer roaming options than they have now, and -- even at this early stage -- I'm almost certain you can kiss goodbye to the worldphone.

— Dan Jones, Site Editor, Unstrung