Will the real 4G please stand up?

Earlier this week, T-Mobile USA, the fourth largest cell phone operator in the U.S., launched a marketing campaign calling its newly upgraded network "America's Largest 4G Network."

The claim has ruffled more than a few feathers at T-Mobile competitors, namely Sprint Nextel, which has been helping its partner Clearwire build a nationwide network using a technology called WiMax that it claims is 4G.

Verizon Wireless is also building a "4G" network using a different technology called LTE or Long Term Evolution. It plans to launch this network in 38 markets by the end of the year.

So is T-Mobile's upgraded network actually 4G? Technically, the answer is no. But it's important to point out that neither is Sprint's nor Verizon's.

While current versions of WiMax and LTE are typically referred to in the industry as "4G," they do not actually meet the International Telecommunications Union's strict definition. The ITU, an agency within the United Nations, is the international standards body that officially designates wireless technologies as 1G, 2G, 3G, and now, 4G. Last month, the group certified future implementations of LTE and WiMax as 4G. But it did not certify current implementations of these technologies as 4G.

To be legitimately considered a 4G technology by the ITU, the network technology is required by the agency to be IP-based and use orthogonal frequency-division multiplexing (OFDM). The other main requirement is that the technology needs to support peak download speeds of 100Mbps. The current flavors of LTE and WiMax are not that fast. And neither is the technology T-Mobile is using, which is called HSPA+.

That said, the network upgrades all four major wireless carriers have implemented have made their networks faster. Average 3G services offer between 700Kbps and 1.5Mbps. Sprint's WiMax service, built by Clearwire, offers average download speeds of around 6Mbps, Sprint has said. And Verizon claims that tests indicate it is getting download speeds of between 6Mbps and 12Mbps on its precommercial LTE network. T-Mobile's HSPA+ network also gives a significant boost, with speeds between 3Mbps and 7Mbps.

It should be noted that AT&T, which plans to test LTE next year, has also upgraded its network to HSPA+. AT&T is not claiming that its upgrade is 4G. But it is the same technology T-Mobile is using, and it offers the same speedy downloads.

So what does this mean for consumers? Well, there is no doubt the marketing terms being thrown around are confusing. First and foremost, consumers should recognize that all four major wireless carriers are in the midst of upgrading their networks, and that all these next generation networks should provide comparable speeds.

But there are a few caveats consumers should be aware of.

1. Current 3G phones on any operator's network will not take full advantage of the new network upgrades. You will need a new phone that is WiMax compatible for Sprint, LTE compatible for Verizon, and HSPA+ compatible for either T-Mobile or AT&T. Sprint already sells two 3G/4G smartphones, the HTC Evo and the Samsung Epic. T-Mobile has just introduced two HSPA+ handsets, the HTC G2 and the HTC MyTouch. Neither AT&T nor Verizon have announced handsets that use their latest network technologies. Verizon has said it expects to have LTE handsets on the market by the end of the first quarter of 2011. AT&T has introduced a wireless laptop card but hasn't indicated when its HSPA+ handsets will hit store shelves.
2. Network performance is also affected by multiple factors, in addition to network technology. The upgrades boasted of by carriers will no doubt boost performance for new devices. But how much of that is felt by consumers depends on lots of factors, including how loaded the networks are. Wireless is a shared medium, so the more users sharing the resource, the less bandwidth is available for individual users.
3. Network coverage is a major factor consumers need to consider as well. If you have a "4G" phone, it will get the full benefit of that fast network only if you are using it in an area where there's 4G coverage. Otherwise, the phone falls back to the older generation technology. Sprint (via Clearwire) and Verizon Wireless are building new networks using new technologies. So it will take them a little while to build the networks to meet their current 3G footprint. Clearwire is in more than 55 markets today and is adding more each week. Its goal is to reach 120 million potential customers by the end of 2010. Verizon plans to be in 38 markets across the country and offer service to 110 million potential customers by the end of 2010. And within three years it will be everywhere its 3G service is available today, covering 285 million potential customers. T-Mobile's HSPA+ network is in 65 metro areas today and is available to 120 million potential customers. And by the end of 2010, the company has said, it will be available in 100 markets to more than 200 million potential customers. AT&T's HSPA+ network will reach 250 million customers by the end of the year and will be available everywhere its current 3G service is available. So in terms of coverage, AT&T will have the largest, fastest wireless network in the U.S. this year, regardless of whether you call it 4G or 3G.

T-Mobile's claims of the "Fastest 4G network in America" come as wireless operators try to one-up each other to win new subscribers. In an era when U.S. mobile phone penetration is nearly 100 percent, claims of faster networks and hot new devices are what carrier marketing teams use to set themselves apart from the competition.

Previously, operators may have competed on price or network reliability, but today they're competing on speed and cool devices. This trend is largely driven by consumers' appetite for smartphones, which are data hungry devices.

There is no question that wireless operators are playing fast and loose with their marketing claims. And it's likely that the advertising wars will only get noisier, which will make it even more confusing for consumers to decide which device and which carrier is best for them.