Gbcue Premium Member join:2001-09-30 Santa Rosa, CA |
Gbcue
Premium Member
2013-Nov-25 2:46 pm
Antennas?How would this work? Air to ground antennas or aircraft satellite relays (like current WiFi)?
I welcome the ability to use my phone for data to my carrier's antennas and not pay extreme in-flight WiFi prices. |
|
|
bnceo join:2007-10-11 Bel Air, MD |
bnceo
Member
2013-Nov-25 3:04 pm
I wouldn't even dare use the phone data. It's probably unreliable and slow. WiFi on planes will only get cheaper and better. |
|
|
to Gbcue
A picocell mounted in the cabin - relay to cellco by whatever method the airline is using for broadband (satellite or dedicated radio). You will pay to use this - your cellco will treat it like a roaming call. |
|
NickD Premium Member join:2000-11-17 Princeton Junction, NJ
1 recommendation |
to Gbcue
It is physically impossible for your phone to maintain a connection to your carrier's antenna while on a plane going 500 mph at 35000 feet.
At that height, your phone sees hundreds of towers. Many of them are on the same frequency, since they are designed to reuse the same frequency between cells that are far apart from each other. The network was also designed to hand off between cells with enough time so a car going 70 mph won't have their call dropped. On a plane, you're in and out of a cell's coverage area in seconds, and it's designed to hand you off to the next cell, not a cell hundreds of miles away.
The network for delivering wi-fi in flight is designed for only use by planes in flight. They only have transmitters every few hundred miles. Because of that, it won't work unless the plane is high enough to see a transmitter, unless the transmitter is based at the departure city.
The FAA has cleared letting cell phones operate in flight. The FCC wants to clear letting those cell phones actually be used in flight. |
|
|
In the old days that might have been a problem, but with the invention of orthogonal frequency modulation you can have multiple carriers on the same physical frequency with no problems - in fact, they are designed to do exactly that because it makes more efficient use of the spectrum. GSM may not like that too well as it uses TDMA, but CDMA and LTE (which uses OFDMA) should be ok.
The only remaining issue is the Doppler effect, but that isn't enough to completely kill the signal, rather it'll just disturb it a little at best and make it somewhat crappy at worst (in the grand scheme of things, 500mph is extremely slow compared to the speed that radio waves travel, so it's not going to bother their arrival rate a whole lot.)
The passengers on united 93 were able to successfully make phone calls using their mobiles (in addition to the in-flight system.)
The biggest concern would be whether or not your battery can handle doing so many handoffs, and whether the person on the other end can tolerate being disconnected every time you leave the range of a cluster of towers. |
|
|
to NickD
Good points. |
|