Federal regulations forbid making calls from cell phones while aboard U.S. commercial planes in-flight, but Wi-Fi services could eventually permit voice and video calls over the Internet for a fee.
Airlines are struggling to make in-flight Wi-Fi profitable, and some analysts have suggested the airlines need to provide more than the email and Internet browsing offered on some flights using services from Gogo and Row 44.
The question boils down to whether U.S. passengers -- and airline flight crews-- would want to put up with calls made by people sitting next to them, analysts and airline officials have said.
Airlines in many countries outside the U.S. have allowed in-flight calls for two years or more, often using a system that channels the wireless signal from a passenger's device to pass securely and safely through a router on the plane to satellites or towers on the ground.
For example, OnAir in Switzerland ( download pdf ) lists 25 airlines, including AirFrance and British Airways that use its GSM wireless service for voice calls, with callers billed at international roaming rates. Separately, passengers can access in-flight Wi-Fi with OnAir for browsing and email.
"In-flight voice is an interesting topic," said In-Stat analyst Amy Cravens. "Airlines for the most part [especially in the U.S.] continue to resist it to preserve the passenger experience, but many travelers indicate they would want the service."
Cravens and other analysts say there are no dangers of interference with a plane's communications or navigation systems with in-flight Wi-Fi systems. Many experts also say that regular cell-phone calling without Wi-Fi is safe, but the Federal Aviation Administration and Federal Communications Commission still bans the service.
The FCC reconsidered its ban and launched an inquiry in 2004, and in 2007 the agency ended up keeping the ban in place , saying there wasn't enough technical information on whether cell phones used onboard aircraft would cause harmful interference to ground-based networks.
The FCC's position led to a public debate over cell-phone usage in 2007. There were suggestions at the time that continuing the ban was simply a means for the airlines to find ways to charge for calling services.
But using a Wi-Fi channel for voice or video calling opens up many possibilities, as long as the airlines and the public want to head in that direction, analysts said.
"From a technical perspective, there is no concern [with voice over Wi-Fi] with interfering with operational communications, so it is more of a security and passenger experience matter," Cravens said. "I have not seen any movement on this topic by either the FAA or airlines, but would not be surprised if eventually the ban is lifted."
Jack Gold, an analyst at J. Gold Associates, added: "I've never seen actual credible proof that cell phones on planes caused any interference problems. So in my opinion, turning off your phone on a plane is an unnecessary requirement."
Gold added that many people probably forget to turn cell phones off in-flight despite the advisory given by flight attendants.
Analysts said some anti-terrorist groups and government security officials have worried that voice calling from a plane (either by Wi-Fi or cellular) could be used by a terrorist to coordinate an attack from a plane. Federal Homeland Security officials did not respond to a request to comment on that matter, however.
The U.S. airlines have the biggest stake in the question of allowing voice or video calling at some point, perhaps with a fee charged and using a secure and safe system. Several airlines were contacted to ask their position on the matter, including American and United, but none responded.
Matt Hamblen covers mobile and wireless, smartphones and other handhelds, and wireless networking for Computerworld. Follow Matt on Twitter at @matthamblen or subscribe to Matt's RSS feed . His e-mail address is firstname.lastname@example.org .
Read more about wireless networking in Computerworld's Wireless Networking Topic Center.