LTE is an amazing technology—but spreading it across the world and letting smartphone owners use it to their hearts’ content will be a major challenge on both technical and political fronts, a wireless technology researcher said at Interop Las Vegas.

Peter Rysavy of Rysavy Research has been studying the industry since 1994, when the first IP-based wireless technology, cellular digital packet data, was being deployed. Highly available wireless data services took a lot longer to come to fruition than people hoped in the early '90s, Rysavy said, but today’s LTE networks are 1,000 times faster and 1,000 times less expensive per byte than that earlier technology.

LTE is “blindingly fast,” one big reason it’s soared past WiMAX as the "4G" technology of choice, Rysavy said Wednesday in an hour-long session covering LTE trends. But while cellular operators have settled on LTE as the primary technology to replace today’s 3G networks, the transition to LTE could be difficult for both network operators and consumers. Rysavy said that getting enough spectrum will be a hard, political process, and bandwidth congestion may drive service providers to implement data caps that make today’s data plans seem luxurious.

A looming spectrum shortage?

About 500 MHz of spectrum is available for US cellular providers today. The Federal Communications Commission said in 2010 that operators would need another 300 MHz within five years and another 500 MHz within 10 years, Rysavy said.

A skeptic might question whether a shortage is really a possibility with Verizon looking to sell spectrum. But Rysavy says the danger is real.

“Are we on track to deliver that spectrum? Not even close. Not even remotely close,” Rysavy said. “This is a very politicized process. Our biggest hope for new spectrum is to get more UHF channels from the broadcasting industry, which gave up a whole bunch of those in the 700 MHz spectrum band a number of years ago. And they are resisting, so the FCC has come up with what they’re calling incentive auctions. In incentive auctions, broadcasters will actually be compensated for giving away their spectrum. That looks to be like a ten-year process to get through all that. We in the industry are hopeful that it will but it’s going to be complex.”

Rysavy’s research is funded by the wireless industry, with a very long list of clients including network operators AT&T, T-Mobile, Verizon Wireless, and Sprint; equipment vendors like Intel, Juniper, Nokia, and RIM; the US Department of Defense; software vendors including Microsoft, and many, many more.

But he was willing to criticize the industry for playing fast and loose with the definition of 4G cellular networks. Even today’s LTE doesn’t meet the original definition of 4G set out by the International Mobile Telecommunications-Advanced (IMT-Advanced) requirements, which states that 4G networks must operate in up to 40 MHz of spectrum and meet various spectral efficiency tests.

"Marketing types at some of the operators got carried away and started applying the 4G term to just enhanced 3G as well as LTE,” Rysavy said. “The IMT caved in, issued a press release and said, ‘That’s OK, you can call it 4G anyway.’”

LTE-Advanced isn’t as far along as LTE, but would meet the original 4G definition. It is also projected to hit 1 Gigabit per second download speeds, way faster than LTE. Rysavy said, somewhat jokingly, “It remains to be seen whether LTE-Advanced is going to be positioned as 5G. It might be.”

Bandwidth, not name games, is what matters

More important for users is what the services will actually offer. Today's LTE networks have peak network speeds of 70 megabits per second down and 35 up. But the actual bandwidth promised by carriers ranges from 6.5 to 26.3 megabits per second down and 6.0 to 13.0 up, according to data Rysavy showed.

Even those speeds may not be reached all the time. As fast as LTE is, Rysavy noted that it can still only carry a fraction of the data that old-school fiber cables can. Today’s cellular data caps can be 2GB or 3GB a month, while Comcast offers 250GB to home Internet users.

The discrepancy is not an accident—it’s dictated by the available capacity. While one wireline user might get 50 megabits per second, in a relatively busy cellular area you could have a few dozen people sharing 14 megabits per second of bandwidth, Rysavy said.

It gets much worse in stadiums, which are having to install their own distributed antenna systems so sports fans and concert-goers don’t enter a cellular black hole when they arrive for an event. If the faster speeds of LTE do, as some believe, encourage users to consume more data, it might be eaten up a lot more quickly as the proportion of cellular subscribers on LTE rises.

Data caps are just the beginning

That’s one reason the days of unlimited data plans are going by the wayside. Unfortunately, it may only get worse. Think about how consumption-based electricity pricing works, where how much you pay depends on whether you use it during or outside of peak hours—now imagine that model being applied to cellular data.

“I think what you’ll see is prioritized traffic,” Rysavy said. Verizon, he noted, is developing a “Turbo” button that would let consumers get a temporary bandwidth boost, for a fee.

An application can tell a user “if you click here your usage rate is going to go up. You’ll pay more but your traffic will have higher priority,” he noted. “Will people pay for that? It remains to be seen. I see it as Verizon sticking its toe into the QoS (quality of service) waters to see if its toe gets bitten off, or if something good comes out of it.”

Could there be benefits to consumers from an electricity-style model? Although it’s hard to imagine cellular providers giving consumers a big price break, it is possible. Just as electricity can cost different amounts at different times of day, so could data, Rysavy speculated. Maybe people downloading stuff at 3am will pay less, or perhaps cheap plans that don’t allow streaming video would be offered.

“Over time the pricing has to become more creative,” he said. “At some point people just have to pay for what they get.”

Although Rysavy spent most of his presentation discussing the limitations and challenges related to LTE, he’s a big believer in the technology. “It’s going to sound like I’m down on LTE. I’m actually very enthusiastic,” he said. In addition to providing fatter pipes for data to travel across, LTE will significantly reduce latency, both in the time required for data to make a round trip and the time required to start transmitting, he said.

LTE uses OFDMA technology (Orthogonal Frequency-Division Multiple Access) to deal with challenges imposed by the speed of light, Rysavy said. To dig deeper into OFDMA and many other cellular technologies, you can read some of Rysavy’s freely available (and lengthy) reports.

LTE is faster, but 2G and 3G are not going away

The US is adopting LTE faster than most of the world, and is expected to have good coverage for most of the country by the end of 2013. That said, older cellular technologies are not going away anytime soon. You might get a new version of the iPad each year, but cellular network technologies evolve on decade-plus time frames.

The GSM 2G technology deployed in the early 1990s is only now hitting its peak adoption some 20 years later. Even at the end of this decade, the 3G HSPA will still be ten times as heavily adopted as LTE, he said. Today’s LTE phones fall back to 3G or 2G for voice calls, although operators are preparing voice over IP modes for LTE devices.

Unfortunately, LTE adopters who travel a lot may have difficulty getting on LTE networks everywhere they go. As of now, LTE phones from one US provider won’t work on another US provider’s network, and internationally “roaming is an issue because every country in the world is deploying on different bands,” he said. Long story short, you’ll be roaming on 3G for quite some time.

LTE users who suffer from awful battery life may welcome the fallback to 3G. Rysavy said he’s hopeful that battery life will be sorted out, although if LTE users do consume more data than the rest of the world, batteries will drain more quickly regardless.

Still, there should be ways to manage all this. Video streams can be sent to a smartphone at 200 kilobits per second, instead of a megabit per second—while the difference might be noticeable on a tablet, it likely won't be on a phone, Rysavy said. Separately, new WiFi technology promises to make connection to public hotspots seamless and password-less, potentially offloading a lot of traffic from congested cellular networks, as we've noted in previous coverage.

Network operators will have to find ways to let consumers do the stuff they want to do on phones if they want to keep customers. But ultimately, Rysavy does believe managing the demand for bandwidth will take cooperation from the users.

“It’s going to take a whole bunch of approaches at the same time that will require people to be more aware of how much data they’re consuming,” he said.