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Cell Phones on Commercial Flights by 2006?
NetCurl writes "I heard the news on MPR's Marketplace today. Apparently the non-profit Radio Technical Commission for Aeronautics is studying the effects of wireless and other portable communications devices on commercial airliners. I've already noticed that a couple airlines have loosened requirements on when you can use your cell phone on the ground. Is the next step wireless access in the cabin, and loud cell phone chatter in the skies over the mid-west?"
Please god no.
Can you imagine a whole bussiness-class row all talking so damn loud and so full of buzzwords that makes you want to yank off their arms, so they can't call again?
No, neither do I, and I'd like it to stay that way.
Moderation: +4. Modded 70% Funny and 30% Overrated. 100% Saturated.
They will find some way to charge you for the privilege of using your own cel phone.
I don't want to be surrounded by people on the plane yakking into their cellphones. If cellphones are allowed the cabin noise will be insane.
They only emit "harmlessness
tcd004
How is this any different from someone talking to the passenger sitting next to them? Airplanes aren't movie theaters where people are expected to sit stoically and quietly. Many people are social on airplanes and I don't see how this is any different at all.
Hmmm... screw cell phones, how about WiFi? I'd much rather have WiFi on a plane than a cell phone and other people using it wouldn't really bother me.
Feel free to mod me "-1 - Angry Jerk".
Must have been an AA exec. Or some asshole with a cellphone glued to his ear.
Although the airlines, and the FAA might end up not carring about cell phones in use while in flight, the cellular carriers certainly will.
The whole concept that allows cell phones to work (that the signal strength at distant cells will be much weaker) only works when all of the phones are close to the surface of the earth. When the users are above the surface significantly, the relative distance between the user and multiple cells isn't very much.
A single user in a airplane making a cell call could easily consume the resources that a few hundred users would on the ground.
Filling the sky with people talking on cell phones could easily render most cell networks nearly useless.
Cell phone technology is based in part by determining which tower can hit you with the strongest signal, as each tower represents a 3-8 mile block of space.
When you're 50,000 feet in the air, you're 8 miles off the ground, and usually moving at a pretty nice rate of speed as well. Will cellular towers be able to properly figure out which tower should be handling the call, and properly do the tower-to-tower handoffs we take for granted when moving down the highway?
I always thought that the no-cell-phones-in-the-sky rules were not just to protect the plane from the unlikely but deadly random autopilot interference, but also to protect the cell networks on the ground from what would be sure to be frequent confusing situations.
Is the next step wireless access in the cabin, and loud cell phone chatter in the skies over the mid-west?
...
So you're worried about those goddamned cellphone ringing in the plane, and people shouting in the phones like mad starving dogs in front of a sausage shop eh ? Well, worry no more, it will not happen : remember, there already is a phone service on most commercial airliners, but how many times in you life have you seen someone use it ?
That's right, at 3 bucks a minute, cellphones might be allowed onboard flights but they won't be used anymore than those seat phones are. Nosiree
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
It's not like the moment you make a call the plane is going to burst into flames and fall from the sky, the main reason some electronics are not allowed on flights is due to the precision navigation equipment.
I'd like to know how they'd deal with 50+ mobiles looking for base stations to connect to?
Be you Admins? nay, we are but lusers!
When you have AirFones, which actually make the airline a LOT of money. Why would they want any part of cell phones?
--
1-800-759-0700
If those annoying cellphone "conversations" that I can't help but overhear in the grocery store are any indiciation of what we can expect in the skies, we're in for some trouble.
"Hey Buffy, guess where I am? No, I'm not at the grocery store. I'm in an airplane over Ohio! Does, like, your parents live there and stuff? No? Oh, they're in Michigan? But isn't Michigan a city in Ohio? Oh wow. Anyhow, the guys sitting next to me on this flight just want to do read their computer books so I'm bored. Yeah, I know, and this book has a drawing of some wierd animal on it, too. Anyhow, Let's talk about the butts of all the hot guys on American Idol! That should last the rest of this five-hour flight! You are, like, such a good friend to do this for me. Nah, don't worry about the phone charges. My parents pay for my cellphone anyhow cause I told them I needed it in case of emergency. What? Oh, you want me to speak louder? Sure thing!"
GMD
watch this
However on an aircraft it'd not be feasible to separate the seating in such a way so many people will just get annoyed listening to people on the phone as well as the annoying ringtones going off all the time.
from his cell phone in his parachutte, enjoy your fast landing and please dont forget to say your preyrs...
compliments of "Cell Lines Aviation"
The lunatic is in my head
Given that there's already a way to communicate when needed, there is no reason to allow cellphones in airplaines. When the price of the calls becomes cheap, the amount of people calling their friends saying, "oh I'm over Michigan right now...I might be flying over your house, look up!" is going to become a real disruptive thing that will only serve to make my trips even more unconfortable.
Warning: Opinions known to be heavily biased.
An idea might be to use micro-cell sites, similar to those they use inside buildings and basements. The airline owner then operates the micro-site and can charge customers for in-flight use accordingly.
Because when you're talking to someone on a phone, especially in a moving jet, you're going to have to talk over the noise and reduced signal strength.
Whisper into your phone the next time you're driving and see if the person on the other side can hear you. Or plug in some amplified speakers on the plane so everyone can hear the movie. See how well that all goes over.
Now I've got no problem with casual use, but we all know how that's going to end up.
That should be the motto of aviation. But just to get a minor avantage for getting customers the airlines seems to ignore this important principle. But this could have terrible consequences. The problem with cellphones isn't just EMV. There are a number of simple solution for that ranging from faraday cages to fixed cable connections on the planes. The real problem with enabling cell phones is that you cannot determine the use of a high tech device just by looking at it's X-ray scans. And a modern airplanes like the news ones of Airbus are 100 percent computer controlled. With a sufficiently concealed device a possible abuser could take over some, if not all controls of the airplane. I think I don't need to point out the further consequences.
So for such security issues the FAA should step in and make such schemes illegal. Otherwise the possibilities of abuse might be demonstrated in a very visible way to all of us.
Owner of a Mensa membership card.
American last year turned its seatback phones off and removed the transmission equipment -- but not the phone handsets -- figuring the fuel savings from the reduced weight were greater than its share of the seatback phone revenue.
I'm a RF Engineer for a major US PCS carrier.
There's no way that our network (nor anyone else's) would be able to handle calls reliably from an airplane.
Our cells typically only cover 3-5 miles in an urban area, and 20 in a rural one. As fast as a plane travels, you'll be changing sites very quickly.
Add to that the fact that our network is designed and optimized for ground level users, and you're looking at a crappy call, assuming you can even orginate one.
IMO, a possible better solution would be a micro-cell installed on the plane that would multiplex the calls back to the PSTN.
The last plane I was one it was pretty useless to chat with others mostly because me and my buddies were back in coach. I don't know what it's like up in the clouds (first class) but talking on a cell phone is a pretty much non-issue with the engines cranked up right outside your window.
Thus, an iPod is a much better traveling companion!
Man, what's wrong with the ppl on here. SUVs suck, cellphone's suck, anything new and shiny sucks... but I uphold Linux like a religion and am anti DMCA anti PATRIOT act... it's like a hypocritical unabomber here...
Anyways. Having cell phones on planes would rock! Most of the time I'm there, nestled between two big, depressed guys, who would want nothing better to do that just like be depressed, smelly, and put their arms on my armrest. So I'm there, bored from the crap I'm reading, and want to start conversations with these ppl, at least, to remove the burden of suffering that I'm under right then... but no, they don't even want to talk!
Now, if I had my cell phones, I could be in touch with my family, loved ones, friends, etc... and then the 4-hour plane ride from coast-to-coast wouldn't be such a drag... having no cellphones on the plane is like asking ppl to not speak in the car while daddy's busy driving.
Philosophistry
If your phone is talking to two or three cells that on ground could never 'see' each other, expect a letter from your company ranting about confusing the network. I don't know what harm it does, although I have read a couple of storys from people who have been wrote to.
and be here now
A few of my co-workers and I were on a private plane and became curious about what the cellular coverage would be like while on a plane. Since the pilot didn't mind, we turned on our mobiles and watched the coverage gauges.
I'd find it hard to believe anyone could have a real conversation via mobile phone on a commercial flight. Given that our plane was relatively slow and low compared to a commercial flight, we zipped from one cell to the next. The way the coverage went from 5 bars to zero and back again every 10-15 seconds, I'd imagine the gauge would be going bonkers when that high up and going that fast.
"RING!"
"Hello?"
"Hi honey, I'll be home in--bzz--<dial tone>"
"RING!"
"Hello?"
"Sorry, lost coverage there for a--bzz--<dial tone>"
"RING!"
"Hello?"
"Cell phone dropped off again. Anyway--bzz--<dial tone>"
But why is the rum gone?
Isn't it strange that people actually believe the story that a phone call was made from a doomed airplane on Sept 11th?
The reason that cellular phones cannot be used during flight is not about safety. When you're driving along, it's not a big deal to transition from the range of one cellular tower to another. When you're in a plane not only are you within a direct line of NUMEROUS towers, but there is also the problem of changing towers almost constantly.
In theory, theory is the same as practice.
In practice, it isn't.
Remember how we're supposed to remember 9/11, and not forget things like the dozens if not hundreds of passengers who successfully got final calls through?
And just to technically debunk yet another cell phone myth, you're completely ignoring the fact that it's pure line of sight straight up, and the farther up you are, the less change there is (you move fewer degrees from the tower, regardless of your speed).
Hell, even noise isn't that big a deal; jets are LOUD, human voice doesn't carry well in such an environment.
--Dan
Three hours as a captive audience, trapped between an aisle seat with some guy talking to his Aunt Mildred about his inflamed hemmoroids acting up and some 14 year old by the window who decided that now is a good time to try out all the 153 ringtones she downloaded while sitting in the airport.
No. Thank. You!
My Webcomic: Asylum on 5th Street
Icepick_: A guy on a cellphone starts talking on a plane. Next thing you know the guy's taking up space on 40 cells, moving faster than the system can comprehend, and the whole thing just crashes and burns.
Woman on plane: Are there a lot of these kinds of accidents?
Icepick_: You wouldn't believe.
Woman on plane: Which PCS company do you work for?
Icepick_: A major one.
Yes, I realize calls were made on 9/11. I realized that it's practically possible. How long did those calls last? How was the voice quality? How well (if at all) did those calls hand off to the next cell site?
And to answer your second question, yes, our antennas and towers work mainly on a line of sight basis. Buy why on earth would we aim our antennas up? You really think that we use an omni-directional antenna? Heck no, all of our antennas are high gain, direction antennas, pointed horizontally, or downtilted to further aim them earthward.
Being 50k feet above a cell site, and you're going to have shit signal, and it's not going to last very long at all.
Personally, I hate flying because the concept of sitting in a mothy pipe with nothing sensible to do but wait does not appeal to me.
Perhaps, affordable internet access in the air could alleviate the burden of being stuck up there for many hours. Even of some of the passengers end up having senseless, loud conversations, it sounds like a good deal.
Even the trade off between the risk of dying from a crash and (almost) dying from boredom tends to shift towards the first option for me ;)
Since when did a Laptop, Gameboy or a Walkman become a triggering device on a weapon of mass destruction? I mean if the planes are so delicate should we really be flying in them? If all OSAMA needs is his sprintPCS, laptop, and a walkman turned on at takeoff to bring down a plane why didn't they try it long ago? What would freak out americans more then watching a plane crash every day? And if it was really a safty issue wouldn't they ban them from the cabin.. ala GUNS, KNIVES? The Generic reason given to turn all this stuff off at take off and landing is that it *MAY* interfer with ILS. Now I have a few tips on how to handle this. FIRST upgrade ILS.. if gameboy and walkmans are fuxing it then it needs to be upgraded.. there are several ways to get around this.. I mean if my CELL PHONE can connect me.. with a BILLON other CELL PHONES without jumping on to the wrong call then you think ILS could be upgraded to freqecny hop as well. Second what about some sheilding around the cabin? Wrap some tin foil around the cabin.. that seems to keep the aliens out of my head. Finally don't realy on ILS in the first place.. I know its tough being a pilot these days.. but put the damn drink down.. grab the big dealy between your legs and look out the shiny thing infront of you. If you can't handle it and need to get drunk on a flight buy a ticket and sit in the back with the rest of the damn drunks.
Except not as funny
for hating him
flambait...but still funny as hell.
...I'll be able to use a cell phone in my flying car!
Why are everybody so strung up about this?
Are you all flying more than 100 times each year? Are all your flights transatlantic, or even longer? Are you so indespensible to your company that it would be a disaster if you were out of reach for some hours?
I fly a lot, and the last thing I need is sitting next to a jabbering idiot for hours without end. It's already a pain in cinema theaters and public places like restaurants.
If you happen to be a compulsive jabber, please consider your surroundings and get a phone that doesn't require you to SHOUT INTO IT.
How small a thought it takes to fill a whole life
While calls were made from planes on 9/11, were the planes at cruising altitude (~30 000 ft.) when the calls were made? I was under the impression that most of the calls were made not long before the flights crashed, when the planes were probably well below 10 000 ft.
(I don't know how much that distance affects signal strength with a clear line of sight, but a factor of 3 in distance means a factor of 9 in the surface area the signal is spread over.)
that his SUV/penis replacement doesn't impress anyone.
Also, cell networks on the ground cover populated areas and major highways--coverage in unpopulated areas is spotty at best, even with carriers with a good network. Airplanes are not usually flying over populated areas or major highways, so coverage would likely be poor for most of a flight even before you consider the plane's speed and altitude (although altitude helps somewhat in areas with few cell towers because hills don't get in the way).
I guess the relevant statistic is what fraction of the country's land area actually has cell coverage? Rate plan maps always have large areas that aren't covered, particularly across the midwest and west, and those maps include large areas that don't actually have coverage anyway.
I'm from Texas so I shouldn't bitch, but the idea of the cast from Fargo jibber jabbering about every inane little event that happened on their vacation... Amtrack's still in business, right?
"Stop throwing the Constitution in my face, it's just a goddamned piece of paper!" - George W. Bush Nov. 2005
If we get cell phones legalized on aircraft, that will be start of getting other devices to be allowed for use. Like Portable TVs, Walkmans, GPS Receivers, Wifi cards, satelite phones, radio scanners, etc. Anyone else believe in the whole US/UK information blackout during commerical flights theory? I do. Isn't also true that a certain ham radio license lets use a certain two-way radio on aircraft?
Add to that the fact that our network is designed and optimized for ground level users, and you're looking at a crappy call, assuming you can even orginate one.
If most of the time, people either get lousy quality or can't call at all, then there would be no reason to have regulations prohibiting the use of cell phones for the benefit of the cellular companies: people would quickly stop trying all by themselves.
That means that either cell phones work from airplanes and the cellular carries just don't like it, or that they really do interfere with flight equipment.
The restriction against using cell phones aboard aircraft is not an FAA rule, it's an FCC rule. When a cell phone was used at ground level or in a building there was no problem, but using a phone at 6 miles up was causing problems with the tremendous range of transmission.
From that altitude the phones were bypassing the protocols that keep the phone talking to only one tower at a time and was causing connection problems for both the user of the phone on the plane, and others on remote cell phones on the ground.
Perhaps the cell phone industry has solved these issues with the conversion to digital, I don't know for sure. But unless these problems have been solved the FCC is unlikely to allow cell phone use from aircraft, baloons or any other "high altitude" craft.
Article X: The powers not delegated... by the Constitution...are reserved...to the people
And that differs from my experience with cell phones at ground level in what way?
Boeing and Intel have been working with several airlines on installation of paid-access WiFi on commercial airliners. As for cell access ... even if it is determined that there is no safety threat (and there probably is not), cellphones aren't designed to work at 550 miles per hour and 40,000 feet in the air. They're flaky enough on the ground. They may work on approach or takeoff, but airliners don't waste any time getting to altitude, where engines operate more efficiently in the extremely cold air.
EFF co-founder John Gilmore was prevented from flying because he was wearing a button deemed to be in "poor taste" and refused to take it off.
If people could interfere with the frequency that pilots use, then children could scream "MayDay MayDay" and play among themselves using cellphones, with bizarre results...Interesting, isn't it?
Uh, what about the woman who called her husband, collect no less, from the "hijacked" plane to announce what was "happening". I believe her name was Olsen. Now, the collect call bit is vital info, cause the airline phones do not make collect calls.
So, perhaps we should have this consortium talk to the white house about how to enable Cell calls, since the airlines have already done so apparently...
Perhaps they can also explain how Box cutters got onto the plane since they were banned items since 1991. I guess that's why the airlines were exempt from prosecution from allowing box cutters onto planes.
Well from the "I heard about it" department, I have recently been approached by a group of people with out a company, that are building a device to take the cell-phone signal band (which interferes with airline equipment I guess) and retransmits at a different frequency, which is appropriately outside the aircraft transmission band. As I understand, it is a piece of equipment that will clip onto your cell phone to avoid the phone actually transmitting unwanted signal. Interesting (but obvious) concept.
You also have to remember that the 9/11 planes were not at normal flying height. They imidiately dropped thier altitudes. I forgot how low they went though. (not including thier final descent...)
(I am not an electrical engineer)
/. yesterday? I am not much for the odds of "It's highly unlikely using your cell phone will take the plane down."
So can someone reconcile the findings in this article with the findings referenced in the article on
Denver Isuzu Suzuki
My anonymous brother is an airline pilot with Continental Express. He and some of the first officers he has flown with have tested cellphones in flight to see what affect, if any, they have on the aircraft systems. What they found is that none of the cellphones tested, from all the major companies, would work above about 3,000 feet.
The cellphone manufacturers are going to lower and lower power output, which means shorter ranges. And since the vertical antennas used on cell towers are designed for horizontal radiation, aircraft are operating in the null area of cell site radiation.
The old analog cellphones would work fine, but I believe analog service is now gone.
Just one or two phones not getting service in the cockpit aren't enough to definitively say problems won't happen. But the only problem my brother and his trusted first officers have found is that they can't get service in the flight levels.
If we are going to have a bunch of boobs with
(c/h)ellphones chattering, my answer is !!!yes!!!
As far as I can tell from various reports out there, there are enough technical difficulties with cellphone-to-ground service on planes that they are not simply going to allow regular cell phone use:
:)
Ars Technica reports that there are two bans in place: the FAA for flight safety reasons, and the FCC for cellphone network interference reasons. (A cell phone can reach too many towers at once, thus interfering with towers other than the one it's actually communicating with) The USA Today article quoted by the Ars article discusses all this pretty well.
So, companies are trying to come up with a solution. One company, AirCell, has been granted "a patent" (US Pat 6,408,180) for facilitating cell phone use in planes. AirCell has a press release touting their patent and technology. USA Today said Aircell would charge a roaming fee to use their network.
The patent discusses the various methods used to reduce interference with ground stations, like antenna polarization.
It also seems to discuss an additional cell site on the plane itself, that is designed to convince all the passengers' phones to talk to it, so that it can efficiently relay the signals in a non-interfering mannor down to the ground.
It ALSO seems like they talk about redesigned ground sites to facilitate this, so you have to wonder what the involvement of each of the cell phone providers will have to be.
(skimming patents is not easy... I might be wrong, but the images help. In TIFF format: diagram of relay system on the plane, special cell sites vs normal cell sites)
It just hurts to think about the infrastructure investment in all these different, competeing cell technologies in the US. Wouldn't it make lots of sense to just GIVE UP and legislate/regulate a single standard. Say, GSM for example. Works for Europe...
- Peter
INsigNIFICANT
This recent slashdot article also covered cell phones on airplanes. If we already know that they are dengerous, then the question is will electronics manufactures redesign their equipment so as not to be harmful? Or will air plane manufactures build their planes so as not to be suceptible to this type of interference? With all the terrorist stuff going on these days, I would think the latter. But since we are still using the same planes for 30 years ago, it isn't going to happen anytime soon. --jdan
Here in the US, or rather, the northeast, Amtrak has also implemented Quiet Car service on most trains serving the Boston-NYC-DC Northeast Corridor. No cell phone use is permitted in the Quiet Car, usually the first coach class car from the front. I've ridden in the quiet car, and the rules are adhered to, which allowed me an extended period of calm, which I admit I used to sleep most of the way between Philadelphia and New York. An airplane, unfortunately, does not offer enough space or enough freedom for people to sort themselves into cell phone users and non-users. Chalk it up to the relative merits (and lack thereof) of the aeroplane as a means of travel.
It is a shame that by focusing on cell phones they are missing the opportunity to leap-frog the whole 1G, 2G, 3G thing and get straight to where people on the ground are slowly progressing - pervasive WiFi which, combined with VoIP, can subsume all of the functions provided by cell-phones today.
You need something more powerful than a cellphone to bring down a plane. :) Just a few days ago I flew an AN-24 plane from Nizhny Novgorod to Moscow. Apparently, using cell phones was allowed there.
;)
I guess that's the same principle as with Soviet fighters that used vacuum tubes and were therefore completely immune to EMP-weapons.
Future Wiki -- If you don't think about the future, you cannot have one.
When using your cell phone from higher altitudes the call is basically free ( dooesn't show up as time used). The towers don't get confused and don't know where the call is coming from.
:)
don't ask me how I know the calls are free
Anyway. You can legally use your cell phone if the plane is flying under VFR (visual flight rules), but you cannot use it if the plane in under IFR ( instrument flight rules). All commerical aircraft fly under IFR.
As a commercial pilot and electronics geek, I'm concerned with the proliferation of electronics on board airplanes. No, I can't say what the effect of a cell phone is on the incredibly complex system of both analog and digital systems on the typical airliner. The problem is, no one else really can, either. Sure, the frequencies transmitted by cellphones are quite a bit different than avionics. But so is an FM radio. Next time you're talking on your cell phone, hold it next to your FM radio and see just how much interference you get. I'm not aware of any detailed studies on the effects of modern consumer electronics on navigation equipment, but with the speed with which new devices are always coming out, you can bet that even if one was done, it would be obsolete within a year. Sure, the technology exists for protecting and shielding electronic equipment. Given that it would cost the manufacturer more $$$ in the long run, who really thinks that any of that technology would be voluntarily implemented without being mandated by the government? Maybe going a mile off course at 35,000 feet is no huge deal, but think about that the next time you're sitting in the current generation of airplane shooting a CAT-III ILS approach down to near-zero/zero visibility. You're descending through 100 feet, you can barely see the wingtip through the fog, and you hear the cellphone that the guy next to you put in the overhead baggage and forgot to turn off, ringing......
Specifically on air canada.. they can't be arsed making a personal video system or decent inflight audio, because it doesn't make them money, but they'll spend $x0000 on putting hundreds of airphones in each aircraft for the cattle to spend $20/min on. Like I said, it's offensive to me :P
Why don't you look at the American Airlines' onboard technology page? It clearly states the airphone and instructions on how to use it, as well as it's availability in North American and worldwide.
Warning: Opinions known to be heavily biased.
"...in the event of a water landing, your seat cushion may be used as a flotation device. Your cell phone may be used during this flight, but be aware that it is not necessary to blather loudly into your phone. Your party will hear your voice even if you can't, you dopey fuck."
A powered-on cellphone creates a basic connection to all the cell sites it can see. It does this so that it and the cellsite can evaluate which one has the best signal (and isn't full) and to allow seamless hand-offs between cell sites.
If you turn your cellphone on at 30,000ft, chances are your phone can see a heck of a lot of cell sites. Note that I didn't say 'make a call'.. I said 'turn your phone one'. This is an important distinction. It will attempt to establish a connection with as many cellsites as the phone's firmware can handle concurrently. I've no idea what this is these days but my old old old siemens s3 had a debug mode and it would track about 5-10 sites at any one time.
Let's say that there are 50 cellphones that are powered on, and that each cellphone can track 15 cellsites. Because of the height, those phones are very likely to find 15 sites despite downward pointed aerials on the ground.
And the upshot of that is that with all the channels used up on the ground under the plane, people trying to make calls will find that there are no longer any channels free over a large physical area on the ground.
Secondly, if you turn your phone on in a plane and it is physically very far from a cellsite, then the frist thing the phone does is increases its power output in an attempt to reach further.
This is something I've worried about before because we have a server room with very very bad cellphone coverage at work. Given that there is a chance that the RF signal will cause an electric current through induction inside one of the servers, it's logical that the stronger the RF signal, the more likely that chance is.
Ironally, it seems to me that the best way to reduce the chance of EM interference in a server room is to ensure that there is GOOD coverage in there, so that the phone only needs to transmit at the lowest power setting.
Now think about the navigation system in the plane - if all the cellphones are finding weak signals, and they all turn their power output up to maximum, what does that do to the change of a phone interfering with the navigation system.
Is this like a movie reference or something?
--
Mod up a post Rob doesn't like and you'll never mod again
The problem with this is that the antennas aren't pointed up.
Go here and take a look at the specs on the SRL480, or 488 (which is the omni antenna that my employer uses on almost all rural sites). You'll find that the vertical beamwidth on the 480 is 6 degrees (the 488 is 5). That's +/-3 degrees from horizontal.
Just because it worked on 9/11 dosen't mean that it can be expected to work on planes that are higher,or are travelling across sparsely populated rural areas (Montana, Arizona, Texas...)
---
"I can't complain, but sometimes still do..." Joe Walsh
So technology would finally be catching up to what the passengers on the hijacked flights of September 11, 2001 were capable of? The cell phone calls that never appeared on their phone bills? Where can I get such phone service?
I took a flight to Houston about a month ago(too damn hot there btw) and they allowed cell phone use before and after take-off. The only times they had qualms about it were during the actual take-off and the landing. Not only were you allowed to use any electronic devices, but there were also Verizon Wireless phones in the back of every seat complete with internet access and credit card swipers. Not too shabby.
You're nothing; like me.
It will attempt to establish a connection with as many cellsites as the phone's firmware can handle concurrently. I've no idea what this is these days but my old old old siemens s3 had a debug mode and it would track about 5-10 sites at any one time.
Not quite.
The phone listens (recieve only) and identifies the base station with the best signal strength, then establishes 2 way communication with that one base station.
The phone monitors the best 10 (IIRC) signals and passes that information to the one site that it is communicating with.
When the phone moves solidly (there is hysteresis involved) into the coverage area of another site it establishes two way communication with that site (and stops talking to the former site).
(this is true for GSM. TDMA phones only know about the site they are currently using, the base stations listen for the mobile signal strength of their neighbours)
---
"I can't complain, but sometimes still do..." Joe Walsh
Hate to belabor the point, but if cell phones didn't work _at all_ on planes, you wouldn't need to ban them, because people wouldn't use them, because people don't use things that don't work.
Apparently the voice quality was decent enough to have minute-long conversations. Of course, the demand for service was...rather inelastic. But I'm really getting tired of engineers claiming impossibility with a preponderance of the evidence against them. Yes, the planes may have been at non-cruising altitude, but guess what -- planes spend alot of time there.
Regarding pointing down -- I'm sure you've heard of multipath. I know you're aware that concrete reflects Ghz-level signals relatively well. Have you considered that the ground itself reflects RF? Sure, there's a _huge_ dB loss...but so what, cell phones deal with trees and how much do those suckers sap signal strength?
Anyway, it's most likely that cell support will be granted by throwing a GSM base in the plane itself and using a dedicated long range downlink frequency to carry the calls. This will keep signal strength relatively low (since the phones will be unusually close to the base station) yet remain profitable (either by jacking up the rate, or by the fact that certain users have nothing else to do _but_ use their cell.)
--Dan
Fight Club.
I didn't try my cell phone, but I did accidentally fire up my CDPD modem on a place a few days ago (Didn't notice the CDPD card was in my laptop), I wasn't able to establish a connection, and it was jumping between sites rapidly.
I definitely was able to identify the existence of cell towers though, and I suspect I'd have been able to force the issue and get a connection, but I doubt it would have been stable enough to do anything of interest.
Give a man a fish, he'll eat for a day, but teach a man to phish...
I don't think there is a lot of demand for phones at cruising altitude. You either remember something right after take off, or you want to announce your arrivel before landing. None of these would take place anywhere near cruising altitude.
Cell phones are electricaly noisey. A GSM phone sends out all kinds of nasty chips that get into everything. The problem is when a plane is in the clouds, there isn't much keeping it on course. There are a few gyros and the VOR (most planes still don't have GPS). At altitude, drifing off course isn't much of an issue but during an ILS approach, it could be a major disaster. An ILS approach is the pilot is looking at the instruments. There is a glide slope indicator (which a phone can mess up, I've seen it), an altermter which is based on ice not getting on the static port outside of the plane and the inner marker which is a low powered AM tranmitter. If your on the glide slope and you don't see the runway before the plane gets 200 ft above the runway (which should be when you pass the inner marker), you can't land. A modern airport will use lasers to measure the lowest level of the clouds and if they are 210 ft above the runway, they will let planes land.
So I can see the point where people get used to using their phones in the air and then some joker decides that since its ok most of the time, its ok to make a short call just before landing and flips on the phone as the plane hits the 200 foot from the ground mark and interfeers with something giving a pilot a false sense of position.
I see allowing more cell phone in a plane as setting a bad precedent.
IIRC, the FAA didn't have a lot to say about cell phone use in the air(at least in the FAR's a few years ago), but the FCC did. I believe that the reasons are the consumption of resources and/or billing issues.
Ive got news for you.. I am a pilot. I use my cell phone all the time. works fine. The main reason passengers are not allowed to use their transmitters (of any kind) in flight is that it can cause subtle errors in navigation without warning. When i do it, i know that im transmitting, and anticipate strange readings for the instruments and can stop the transmission if its a problem.I cannot anticipate the actions of passengers behind a locked cabin door 20 rows back. but as for the technical does it work aspect? Yes it works. its even encouraged in the event of a comunications failure in flight. I have EXCELENT reception at 20K+ feet using GSM,X1,PCM etc.
Who said they are missing it? Lufthansa is going to offer Wi-Fi, and Connexion by Boeing is going to have both an ethernet port and Wi-Fi component.
Wi-Fi has the opportunity to be a major cash cow for airlines, and from what I see, they're moving in for the kill.
Isn't the average jet airliner moving too fast (what, over 600MPH/950KPH) for the mobile handset to keep connection with one cell long enough to be adequately/reliably handed off to the next cell?
I see cell towers every few miles along the freeway. Assuming each is a cell, and that the maximum range of a cell isn't much further than that, won't the phone have a b|tch of a time maintaining contact with any one cell before it passes out of range?