What the heck's a 4G network?

Those Sprint commercials are  intriguing -- for me, the part about streaming live to the web in particular. I wonder what that's going to do to those big white satellite trucks the TV crews drag around to every news event.

But what is a 4G network? Here's an explanation from wiseGeek:

A 4G network is the fourth generation of wireless communication. While still in development, the foundations for the replacement of the present network is currently being researched and constructed by the cellular phone industry and other technology developers. The overall goal for the network is to provide a comprehensive and secure Internet Protocol solution with much faster data speeds than previous generations.

What works on a 4G network? Walter Mossberg, The Wall Street Journal's personal technology columnist, answers a reader's question.

Q. If I am correct, today's electronic devices made to operate on 3G networks will work on 4G networks. But will the newest of them—such as iPads, iPhones, and Android phones—achieve 4G speeds on 4G networks?

A: You are incorrect, unfortunately. Today's 3G phones and other devices cannot work on the new and coming 4G networks. Those new networks require devices with different internal radios. On the other hand, the few current 4G devices—mainly devices from Sprint—are designed to work the other way. They can use 3G networks if 4G coverage is unavailable.

How widespread is 4G? Mossberg again:

Sprint has a 4G network in scores of cities, and T-Mobile has a souped-up 3G network in many cities that it says can achieve 4G speeds. Verizon has pledged to introduce 4G service in several dozen cities by year-end. AT&T is planning to start rolling out 4G next year.


Two important caveats apply here. First, the term "4G" is a slippery one. While all of these networks offer faster data speeds than traditional 3G, they don't actually meet the technical definition of 4G speeds set by the international standards body that defines such things. Second, to get the full speeds offered by these new networks, most people will need a new phone. Currently, there are only a handful of phones that can do so.

More here about 4G networks.