FAA May Expand In-Flight Device Usage Rules
Though Rule Changes Won't Allow Voice Calls
The FAA this week announced that the agency will be taking a closer look at whether or not they should allow broader use of e-readers, smartphones and other devices while in flight. As it stands, and as most of you are aware, flyers are urged to avoid using any of these devices until the plane reaches at least 10,000 feet. According to an FAA press release
this inquiry would focus solely on data and would not involve allowing in-flight voice calls.
This fall the agency says they'll launch a study group including pilots, device makers, plane manufacturers and even flight attendants to explore the issue for a six month stretch, after which they'll report their findings to the FCC and FAA, with unspecified rule changes surfacing an unspecified amount of bureaucratically-belated time later:
The government-industry group will examine a variety of issues, including the testing methods aircraft operators use to determine which new technologies passengers can safely use aboard aircraft and when they can use them. The group will also look at the establishment of technological standards associated with the use of PEDs during any phase of flight. The group will then present its recommendations to the FAA. The group will not consider the airborne use of cell phones for voice communications during flight.
The end result may not be a total lifting of the 10,000 foot rule, but the rules may become more flexible -- such as allowing more leeway for device use during delayed flights, and lowering the altitude limit to 5,000 feet. That's because interference hasn't been the only concern; the industry has also worried that passengers need to pay closer attention during take off and landings, and that un-stowed devices could add extra projectiles to the cabin during emergencies.
interference The issue with cellular service from an airplane isn't interference with the aircraft, it's potential interference with the reverse link on the cellular network. Once at altitude, your mobile will have a clear line of sight to dozens of base stations. Transmissions from it will be heard by each of those base stations, not just the one you happen to be connected to. The cellular network was not designed to cope with this, mobiles are only supposed to be heard by a handful of stations at a time. Being heard by dozens of stations will lower the signal to noise ratio for reverse-link transmissions from other customers, with the end result of degraded service for them.
This is also an issue with the forward link, though that will only degrade service for you, not others. Your mobile will hear dozens of different base stations at the same time, all transmitting on the same frequency. This will significantly lower the signal to noise ratio of the transmission intended for your mobile and make it that much harder to maintain a connection to the network.
The way to fix this is with picocells installed in the aircraft itself. The mobiles would then transmit at a reduced power level that wouldn't cause issues with the macro network on the ground. The forward link works better too, the picocell is much closer and louder than the stations on the ground, so there's no worries about picking out the signal meant for your phone.
The major downside to the picocell concept (other than the self-important jackass next to you screaming into his phone) is you can bet money that the airlines will rake you over the coals for the privilege of using it. Another potential issue is that the airplane would need a minimum of two base stations to cover the various cellular standards, or the airline has to select a 'winner' and alienate half of the people on the aircraft. My bet would be on the latter, they'd sign an exclusive agreement with Verizon or AT&T, customers on a competing standard are SOL, and those on the same standard but with a different carrier get bent over for roaming charges.