T-Mobile claims the largest "4G" network in the country. Verizon's launching its "4G" LTE network later this year. And Sprint loves talking about "4G" WiMax. Thing is, none of these networks are actually 4G. Not by a long shot.
Update: Well they are now, according to the ITU, who's backpedaled on what's really 4G and what isn't:
Following a detailed evaluation against stringent technical and operational criteria, ITU has determined that "LTE-Advanced" and "WirelessMAN-Advanced" should be accorded the official designation of IMT-Advanced. As the most advanced technologies currently defined for global wireless mobile broadband communications, IMT-Advanced is considered as "4G", although it is recognized that this term, while undefined, may also be applied to the forerunners of these technologies, LTE and WiMax, and to other evolved 3G technologies providing a substantial level of improvement in performance and capabilities with respect to the initial third generation systems now deployed.
Who decides what's 4G?
There's like a bajillion massive, international organizations that jockey for position to dictate a lot of what technology standards look like. When it comes to 3G/4G, there are a few major groups at play:
• The International Telecommunication Union is a United Nations agency that, among other things, sets international standards for telecommunications. This group ultimately decides if a wireless technology is 3G or 4G or, like, 9000G. To be considered 4G, a network technology has to meet a set of specs known as IMT-Advanced.
• 3GPP (3rd Generation Partnership Project) is a group of telecom standards bodies that originally got together to develop the technical specs for a 3G network. This group developed the standard for UMTS (Universal Mobile Telecommunications), which GSM carriers use for 3G data transmission. They're also the cats behind LTE, the next-gen wireless network that GSM carriers like AT&T will migrate to. (I highly recommend reading our CDMA vs. GSM primer now if you haven't, BTW.)
• If you've ever bought a router, you're probably familiar with the number 802.11. What that weird string of digits refers to is IEEE 802.11, the set of standards for wireless local area networking, and the working group that defines them. The Institute of Electrical and Electronics Engineers does a lot of things, and one of them is set technical standards. What's relevant here is that a subset of these governing geeks, the IEEE 802.16 working group, standardizes Wireless Metropolitan Area networks—what you know better as WiMax.
None of these "4G" networks is really 4G
Right now, every major carrier in the US is touting a "4G" network that's either available or being rolled out. Sprint is pushing WiMax. AT&T and Verizon are pushing LTE (Long-Term Evolution). T-Mobile is pushing HSPA+ (High Speed Packet Access Evolved). They're all faster than the "3G" speeds than we're used to, with WiMax and HSPA+ delivering consistent, real-world speeds of anywhere from 3Mbps-12Mbps today. But a rep for the ITU told me flatly, "The fact is that there are no IMT-Advanced—or 4G—systems available or deployed at this stage." Calling their newer, faster networks "4G" is "completely marketing" by the carriers, says Gartner analyst Phil Redman.
The ITU has actually just decided which technologies are officially designated as IMT-Advanced—"true 4G technologies" in its eyes—after looking at six candidates. The winners: LTE-Advanced (LTE Release 10)and WirelessMAN-Advanced (aka 802.16m aka WiMax Release 2). In other words, the next versions of today's LTE and WiMax. Despite sharing the names, and being developed by the same groups as their predecessors, the for-serious 4G networks will be "pretty different" at a technical level, says Redman.
If you think top speeds of 300Mbps for LTE and 72Mbps for WiMax are impressive, true 4G makes them look downright pokey. Today's 4G is "not anywhere near what the 4G experience will be in 10-15 years," says Redman. You're talking about speeds of "up to a gigabit a second" in a wireless LAN, and 100Mbps for fully mobile applications. In other words, true 4G is a massive leap, not a dainty skip forward. There's also little things, like full capability for voice in LTE-Advanced, which there's no standard for in the current LTE spec.
The goal of true 4G is to create a superfast, incredibly interoperable, basically ubiquitous global networks. What we've got now and in the very near future is pretty good, and definitely better than what we've had. But they're no 4G.