Want to surf the Internet while you're on a plane? You're not alone — there's a growing demand for in-flight Wi-Fi, and the airlines are stepping up to meet it. Currently there are three separate services — Gogo, Row 44 and LiveTV — that provide Wi-Fi on planes in U.S. airspace, and which ones that are available to you depends on your airline.

What are the differences between them? How much do they cost? And what can you do with that connection? We talked to reps from all three services, putting together all the information in a handy table. Hit the jump for the info, and the answer to the biggest question about airline Wi-Fi: Can it do VoIP?

The Birth of In-flight Wi-Fi

The majority of in-flight connectivity in the U.S. relies on the network used by AirFone, the air-to-ground radiotelephone service that powered those expensive-to-use handsets which have since vanished. In 2006, the FCC auctioned off AirFone's 4 MHz of spectrum to two bidders: AirCell and JetBlue's LiveTV.

Three Wi-Fi Players

Aircell: Aircell is the largest provider of air-to-ground Wi-Fi service via its Gogo in-flight Internet service. It offers all the functionality you'd enjoy at the home or office, though it costs more the longer you use it (see more on the table above).

Aircell's Gogo service uses antennas based on the groud. That means the connection is limited by two factors: geography and congestion. Gogo doesn't work over oceans, and busy routes mean slower access speeds. Still, it's popular for airlines because it's relatively quick and cheap to outfit a plane to use the service (around $100,000 per aircraft, Tom Weigman, executive VP of Wireless Services for Aircell, tells us).

Row 44: Whereas Aircell relies on ground-based antennas, Row 44 uses satellites to deliver broadband to aircraft. It's a more expensive for the airline to implement it, but it keeps a plane covered on domestic and international routes. It's also attractive to airlines because Row 44 lets them set the pricing.

"Typically air-to-ground equipment is cheaper," John Gaidon, co-founder and CEO of Row 44, told DVICE in an interview. "But we believe that the added cost [of satellite broadband] is more than compensated for by its operational virtues." Gaidon also points out that an aircraft flying an international route would need a satellite receiver anyway.

LiveTV: LiveTV is already well known for the in-flight cable, XM radio and movie entertainment service installed on JetBlue (LiveTV's parent), Frontier, AirTran and other airlines, but its Wi-Fi offerings are currently only on one plane in JetBlue's fleet: BetaBlue. Only e-mail and messaging are allowed on BetaBlue — no Web browsing. It's all part of the plan, according to Mike Moeller, VP of sales for LiveTV.

"Who will pay? Are passengers going to pay or the airlines?" Moeller said, pointing out that all of LiveTV's functionality is offered free. "Right now, our approach is people love to watch TV, have a beer and get to where they're going." He sees e-mail and messaging as being the most of what people need in what is essentially a handheld device-friendly approach. Whereas Aircell inspires an office-in-the-sky feel, the folks behind LiveTV feel like airplane seating isn't conducive to laptops. "We call it the praying mantis position," Moeller said with a laugh, describing how people have to sit to use a laptop on a plane. "But we're definitely pro broadband."

Future Challenges

Airlines are tossing all this great technology onto these planes right now, but it's technology that has to last. Planes, according to LiveTV's Moeller, have to be quite a bit more future-proof than other vehicles.

"When you put something on an aircraft it has to last about 10 years," he told us. "How will the technology that is on an airline today keep up in the future? Just about all the technologies on most aircraft seem so old to us now."

Bob Mann, an airline industry analyst and consultant for R. W. Mann, pinpoints LiveTV's concern: "If you wait 18 months, it all changes — it gets cheaper, it gets lighter, and there's lower power consumption." On the flipside, Mann points out, an airline with a fully outfitted fleet, such as AirTran, has a reason to brag. "It'll be a big revenue creator. It'll also be a competitive point of differentiation," he said. "'My entire fleet is done, you don't risk a blackout' — that'll be something to talk about."

Something to talk about, sure, but what will they be saying in a few years? A Wi-Fi capable fleet today probably won't be able to compete with the demands of tomorrow's passengers. It's a growing concern with air-to-ground networks, which could see service quality declining as more airlines take advantage of it. Then again, those same airlines will have an edge over the competition in the short run. Especially, Mann tells us, when it comes to "business customers, who generally pay higher fares and who airlines really want to attract because of that higher margin."

What, No VoIP?

VoIP: Some want it, some don't. The technology can support it and the FCC hasn't explicitly banned it. Not to mention that in foreign countries, in-flight calling is commonplace.

"There's no FCC ban on it; it's a practical policy ban by airlines," analyst Bob Mann said. "This is because there's a real concern voiced by attendants and other customers that they aren't going to get on a plane and listen to someone yak for six hours."

The providers may all have different opinions on how to approach in-flight Wi-Fi, but they all agree with Mann.

"We do see that cellphone use is becoming quite popular in Europe and the Middle East," Gaidon of Row 44 said. "We produce gear that is capable of handling it, but we'll defer to the airlines with what we deploy. We've decided to block VoIP."

"JetBlue doesn't want to have voice on the airplane," said LiveTV's Moeller. "The technology can support it, but the airlines say no, and the passengers say no."

Tom Weigman from Aircell agrees: "Aircell blocks VoIP at the request of its airline partners. This is a reaction to widespread passenger aversion to the idea of many people talking loudly on flights (as we've all experienced before take-off or landing)."

While passengers are seen as unilaterally rejecting VoIP or cellphone access on a flight, that doesn't stop a few from trying. "There will always be somebody out there trying to outsmart us and have a conversation over IP in some new way," Gaidon added, concluding that it's "Sort of a cat and mouse situation."