If the FCC approves a rule change, the remake of this movie will have Samuel L. Jackson calling from an iPhone. (New Line Cinema)

It's been a whirlwind month for air travelers. On Oct. 31, the Federal Aviation Administration relaxed a longstanding ban on in-flight electronics. Then, Europe expanded passenger access to 3G and 4G data services on aircraft. Now, it seems the Federal Communications Commission may be ready to allow phone calls from cruising altitudes.

The combination of new rules and cross-cutting jurisdictions is pretty confusing. What exactly am I going to be allowed to do on a plane? How does that technology even work? We've put together some answers we hope will help.

What can I do with my phone right now?

For the moment, the range of activities is still pretty limited. You can use your personal electronics — music players, tablets, e-readers and so on — during all phases of flight, but that comes with several caveats. First, not all airlines support the relaxed rule. That's because each carrier has to go through a separate government approval process. This has led to some pretty weird situations. For example, Delta Airlines is one of those that lets its passengers use in-flight electronics anytime. But regional carriers flying routes on behalf of Delta might not be approved yet, which is why some Delta-branded flights still won't let you keep your Kindle on during takeoff.

Second, even though you can use your smartphone during takeoff and landing, you can't use it to surf the Internet or make actual phone calls. You can play offline games with it. You can open up your e-reader app and catch up on your novel. But anything that requires an active cellular connection is strictly verboten. You must keep your phones (and tablets) on airplane mode during the whole flight.

Wait. But didn't you just say the FCC is allowing in-flight calls?

Not quite. The FCC has said that the issue may be discussed at its next open meeting. In other words, it's thinking about thinking about it. If the rule actually passes — which seems likely given everything else that's happened in aviation recently — then airlines will be allowed to start offering wireless services at 10,000 feet and up. Just as with the portable electronics rule, however, it'll be up to the individual airlines to support it. And remember, cellular connections will still be prohibited during takeoff and landing.

Why is this being decided by the FCC? Isn't the Federal Aviation Administration in charge of airplanes?

While the FAA governs much of what takes place on airplanes, anything having to do with wireless communications lies in the FCC's court. In fact, the FCC considered relaxing the ban on in-flight cellular use once before, almost a decade ago. But flight attendants and the airborne equivalent of quiet-car diehards killed the idea.

FAA, FCC, whatever. How is all this going to work?

Most likely, the system will look a lot like what Europe has. (Shock: Europe is ahead of us.) Air travelers over there have had access to in-flight data ever since 2008. Granted, you could only surf on 2G speeds until last week. But still!

Europe calls its technology MCA, or Mobile Communications On-board Aircraft. Every plane that supports it is equipped with a base station that creates a mini cellular network called a picocell. All the wireless signals from your phone or tablet get collected by the base station, then transmitted to a commercial communications satellite. The satellite then beams those transmissions down to Earth, where they link up with terrestrial networks and continue on their way like normal.

Sounds great. What's the catch?

It's pretty costly. As long as you're on the picocell, your cellular provider charges you at international roaming rates. These extra fees go toward paying for the satellite connection and other costs. The good news is that if all cellular companies participate, it might crack the market for in-flight Internet wide open so that it's no longer dominated by pricey Wi-Fi services. With any luck, the competition should drive prices down.

What about signal interference? Won't this crash the plane?

Well, planes haven't started falling out of the sky in Europe yet, so I think we're okay.

That's not very comforting.

Sorry. Here's a better answer: The reason why airlines resort to the convoluted satellite method at all is to make sure that only low-power transmissions are involved. There are newer technologies being developed that allow direct air-to-ground communications, but they still generally suffer from limited bandwidth. The satellites provide much faster download rates than direct connections, at least for now.

Are there security concerns we haven't thought of? What if someone, I don't know, puts a bomb someplace, hops on a plane and detonates it remotely?

Sounds like you've been watching a few too many action movies. Okay, I'll bite. Yes, this could plausibly be a problem, but not such a common one that the FCC should keep the in-flight calling ban in place. The Atlantic Wire recently dug into how cellphone detonators work (neither they nor we are suggesting you try this at home). One method is to connect a phone's vibrator to the bomb's circuit board. Call the phone from another phone and get the vibrator to activate, and the bomb goes off. Still, it's hard to see how this poses a credible challenge to in-flight calling. It's not like you can't already trigger a bomb with a phone from elsewhere.

Fair enough. So what do I do about the guy who's blabbing on the phone across the aisle from me?

That's up to you. Unfortunately, airplanes don't come with quiet cars.