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Why doesn't my cell phone work in the air?

I am a pilot.. Usually my signal fades out around 2000feet or so. This seems to be worse with T-Mobile. I flew with a guy who had an iphone on att and it worked fairly well at 9,00ft. I had a CDMA phone a few years ago and it would work at very high altitudes 30,000ft plus. Nowadays, I usually cruise at less than 10,000ft, but I still have no service.
It seems to me that I should get better service at altitude, but this is not the case..It seems like one might have the same problem at high altitude in mountainous regions... .I have googled this for years but never found the answer... I was hoping someone on here might be able to answer my question: Why does my cell phone signal drop out at altitude? (I understand this :http://ashsd.afacwa.org/print_article.cfm?homeID=17917 but I am on a private aircraft) I understand the rules, but they don't explain the loss of signal...
I hope this is the right place to post this and thanks for your help!

iflyabeech said:
I am a pilot.. Usually my signal fades out around 2000feet or so. This seems to be worse with T-Mobile. I flew with a guy who had an iphone on att and it worked fairly well at 9,00ft. I had a CDMA phone a few years ago and it would work at very high altitudes 30,000ft plus. Nowadays, I usually cruise at less than 10,000ft, but I still have no service.
It seems to me that I should get better service at altitude, but this is not the case..It seems like one might have the same problem at high altitude in mountainous regions... .I have googled this for years but never found the answer... I was hoping someone on here might be able to answer my question: Why does my cell phone signal drop out at altitude? (I understand this :http://ashsd.afacwa.org/print_article.cfm?homeID=17917 but I am on a private aircraft) I understand the rules, but they don't explain the loss of signal...
I hope this is the right place to post this and thanks for your help!
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I believe that most cell sites work by line of site. If you are above them then I can see this happening. Besides, cell sites have a limited range anyway. Going straight up... who knows. But I only put my phone on Airplane mode while on flights and turned it on once (feeling rebellious) and had no signal. Of course I wasn't really surprised. Besides, cell towers have to hand off the signal from one tower to another to prevent dropped calls. If your travelling at 300+ mph I can see how that might complicate things as well. But these are just my own theories. CDMA signal is possibly more powerful than GSM. I've been out of the game for a while but again... it's just a theory.

Binary100100 said:
I believe that most cell sites work by line of site. If you are above them then I can see this happening. Besides, cell sites have a limited range anyway. Going straight up... who knows. But I only put my phone on Airplane mode while on flights and turned it on once (feeling rebellious) and had no signal. Of course I wasn't really surprised. Besides, cell towers have to hand off the signal from one tower to another to prevent dropped calls. If your travelling at 300+ mph I can see how that might complicate things as well. But these are just my own theories. CDMA signal is possibly more powerful than GSM. I've been out of the game for a while but again... it's just a theory.
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Sure...but I am usually less than 2 miles high and usually under 200MPH..Signal usually goes out when climbing out at under 150mph...
Thanks for your reply....

I was told a few years ago that it's the association with cell towers being the problem.
If you are going over them at 150mph+ its going to struggle to keep a decent signal....
Although i can confirm satelitte phones do not have this problem (neither does GPS tracking)

Burko said:
I was told a few years ago that it's the association with cell towers being the problem.
If you are going over them at 150mph+ its going to struggle to keep a decent signal....
Although i can confirm satelitte phones do not have this problem (neither does GPS tracking)
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I suppose I should have also stated that the same thing happens when I climb into a strong headwind and travel over the ground at 100mph or less..does not seem to be speed dependent..

I know this thread is kinda old.. but I am still wondering..
I don't think it was anything to do with speed.. I could do very tight circles in the plane and still have the same results....

Just guesswork here, but it could have a lot to do with antenna design. In a prior life I had to design a couple of wireless WANs and found a wide variety of dispersal patterns available in different kinds of antenna. By restricting the pattern you can concentrate all your available power in any particular direction. I'm guessing they narrow the vertical dispersion to get more effective signal strength horizontally. Don't know if that's actually the case, but it sounds good to me.

New to N1 - Signal issues

Hey guys, I bought my N1 2 days ago right when Google announced they were closing down N1 sale..... I was on the fence for long!!! I am trying hard not to like the phone yet since I have seen some signal issues with this phone! I live in downtown and work around the same area, T-Mobile coverage map shows strong signal but my phone keeps switching between Edge and 3G. If that is bad enough, some times it shows 3G and if I try accessing Market, I get data connection lost error!!
When phone was shipped, it came packaged with 2.1.1 and soon after I got an OTA and upgraded to 2.2!!
Is it how it is going to be? I use this phone for work so definitely can't keep it if I can't get good signal. Is there a fix without rooting? Can I try a different radio or something!??
Also, I have contacted all 3 companies in the mix and waiting for the response! Any help to get this thing fixed, if possible, would be greatly appreciated!!!

It could be that you are just in a bad Tmobile/Att area, the Nexus One has a small problem with signal strength, nothing that has EVER dropped a call or stopped me from surfing.

its really sensitive to your hand blocking the antenna. leave the internal antenna exposed by slightly spreading your fingers apart. antenna is on the bottom behind the words HTC.
question: why are so many recent cell phones so sensitive to the hand obstructing the antenna? samsung galaxy s is it worst that i've ever seen. HTC nexus one has this issue, htc incredible, desire, nokia e71, etc. is it because these phones are getting so thin that it puts the distance between our hand and the antenna that much closer? i cant think of any other reason. i refuse to believe that its from poor components considering samsung, htc, nokia, all different manufacturers have the same problem. so it cant be quality of components.

Ive been having the same issue from Day 1 with my nexus but only in certain areas. Buildings where the T-Mobile coverage map shows 3g but it just switches back and forth edge/3g when i pick it up(block antenna)

Thanks a lot for all your response guys! So if I buy a rubberized cover, should it improve the situation?

Don't trust carrier coverage maps. Where I live tmobile promises good coverage. I got zero bars. Try to compare the reception with another phone on tmobile.

blablum said:
Don't trust carrier coverage maps. Where I live tmobile promises good coverage. I got zero bars. Try to compare the reception with another phone on tmobile.
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Its a bummer that carriers lie on their coverage map! This is the only T-Mobile phone I ever owned and I don't know anyone else with T-Mobile 3G handset!! Well I just have to see next few days and decide whether I want to stick with it or not! I really hate to return it though!

Only getting -105 to -111 dBms -- PROBLEM?

I live in "moderate coverage" area(confirmed by 3 separate ATT reps). I got myself the Captivate the wife got the iphone4. In my house, the iphone gets 1 bar and in our home no bars. Obviously no way measure iphone signal in dBm's(good job apple. It is really a walled garden isn't it).
On captivate, i keep oscillating between -105 to -115dBm and from 4 asu to 1 asu. I really really love the captivate and I was looking forward to a decent Android GSM phone since I travel to Europe/Asia a lot. But the signal is really bugging me. A few times, I couldn't hear the other side properly(the iphone was much worse in such cases). I have till Thursday to decide whether I was to keep the phones or return it. I am very weary about committing another 2 years to death-star is this is going to be an issue.
Can people please advise if this is really a problem OR just ignore this and live with this. I really love android but need a GSM/World phone due to my travels.
Please put me out of my misery. I can't make up my mind

Buy an AT&T Microcell if they are offered in your area. That is probably the only thing you are going to he.able to do about the coverage situation.
Sent from my SAMSUNG-SGH-I897 using XDA App

Complain enough about you're area coverage .it will either get you out of your contact, or a free microcell.
Sent from my SAMSUNG-SGH-I897 using XDA App

i complained a lot to 3 different supervisors and they wouldn't offer a free microcell. Would give $70 credit, but did not realize that if I buy the microcell, it add $20 monthly fee. I am not sure if the last supervisor was bullsh****** me, cause the store rep didn't mention the $20 monthly fee.
I was out of contract when I upgrades, so if I return I will go back to no-contract.

i suspect it's reading falsely low or weak - i've got a vibrant and it generally reads the same, where my earlier MT3G would show -63 to -87
but mine doesn't drop calls and pulls 3G and sometimes even pulls down HSDPA
depending on traffic on the web, while showing -111 dBm, mine will test at speedtest.net showing as high as 5.4 Mbps download,
it generally shows 1.6 to 2.6 Mbps but again, all those test results were while showing -105 to -111, same as yours
the Mt3G, while it showed higher signal strength in same spot, never got above 1 Mbps download speed, which is why i'm thinking the signal strength is reading falsely low
if you're not dropping calls and pulling down at least 1 Mbps download speed, i wouldn't worry about it
but in case it helps

I bought 2 at the same time (one for me and then one for the wife). Her's was having the same issue. We have a MicroCell and I get 5 bars and like -85 dBm while her's was showing one bar and -100. Bad antenna. Return it for a functioning one.

themogul said:
i complained a lot to 3 different supervisors and they wouldn't offer a free microcell. Would give $70 credit, but did not realize that if I buy the microcell, it add $20 monthly fee. I am not sure if the last supervisor was bullsh****** me, cause the store rep didn't mention the $20 monthly fee.
I was out of contract when I upgrades, so if I return I will go back to no-contract.
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I could be wrong, but, I was under the impression the $20 monthly fee is only if you use the microcell in conjunction with your home internet to get unlimited (doesn't go against your rollover minutes) calling from your cell number. Thats how you get the MC free, otherwise it's $150.

After trying another 2 reps, I actually found someone who actually figured that my 3g reception is really really weak and shipped me a microcell give me the credit of the full amount. Finally got lucky. Anxiously waiting for it to try out the signals. I will post my findings here. Need to buy a homeplug adapter so I can keep this by the window. I really hope those works out as I really like phone
Sent from my SAMSUNG-SGH-I897 using XDA App

I got the microcell working after some intial hickups. Its been about a week that i have been using the microcell and its working good for me. I get four bars in most of my house which is so much better than no bars. The call quality is much better and all calls are very clear. The iphone and captivate both hold the calls much better now. I am glad this resolved my basic calls issue and i get to enjoy this excellent phone.
Thank you all fpr ur help.
Sent from my SAMSUNG-SGH-I897 using XDA App

What does the service has to do with the phone? I'm confuse. I'm getting the same signal strength I was getting with the iDon't in my home. I don't think it's the phone just the service.
Sent from my SAMSUNG-SGH-I897 using XDA App

I noticed this problem the moment after buying mine. At the store once they powered mine up i walked to the floor model and my signal was 20dbm less than the other. Now in my apartment i get no signal what so ever when my BB would get some. Debating on exchanging mine for another after reading that broken antenna comment
Sent from my SAMSUNG-SGH-I897 using XDA App

My first captivate had a bad antenna and got no signal at all, anywhere, even in front of a microcell at their store it got 0 bars. So return or exchange it. Some of them have bad antennas.

Very good to know, I'll be exchanging mine on Monday
Sent from my SAMSUNG-SGH-I897 using XDA App

Does anyone have data on what good signal numbers i should see? Should I see positive DBm? If so, what? Positive 90? Or is Negative 50 OK?
I can't seem to find good reference material, but I don know when i leave my basement my signal goes from Negative 107 to Negative 95.
Thanks for any references or education.

A higher but negative signal is stronger, with -50dbm being extremely strong, -90dbm usually supporting weak data, voice being acceptable to -95dbm and anything lower than that is considered an unusable signal for most mobiles
Sent from my SAMSUNG-SGH-I897 using XDA App

What is the best signal strength you gotten.? I think mine is -91 it doesn't seem that good. How about you guys? Oh i am in Houston.
Sent from my Nexus One using XDA App

I've personally have seen my phone hit -50dbm which I believe is the highest this receiver will read. However this is very sporadic and rare. On average it is in the 90s which is unacceptable. Even beside my girlfriends BB my signal is always 30dbm lower than hers. Keep in mind dbm is a logarithmically scaled unit so 30dbm means my signal is roughly 10 TIMES lower than hers. 3dbm is twice the power
Sent from my SAMSUNG-SGH-I897 using XDA App

When do you measure your signal levels?
I got same weak signal during cell standby (no phone call, no data traffic).
However!
After initiating data transfer/call signal increases significantly. I'm getting -60-80dbm.
This means radio is saving battery juice when not extensively used, which should be considered positive.

xan said:
When do you measure your signal levels?
I got same weak signal during cell standby (no phone call, no data traffic).
However!
After initiating data transfer/call signal increases significantly. I'm getting -60-80dbm.
This means radio is saving battery juice when not extensively used, which should be considered positive.
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I've noticed this too, at idle if I have one "bar" and I initiate a phone call the bars will increase to 2-3. However, there are times where I am on the fringe of no signal whatsoever to even initiate a call or to use data because the signal received is so low. Also, when my captivate reports 2-4 bars its usually still at -90dbm. I just did a test by calling someone and watching my bars, although the bars went up, while the conversation was still engaged I was only getting below -90dbm. I'm about to head to the store to check out a replacement

Just traded phones, this one seems to have the same issues... I'm curious if the build date has anything to do with this. My first Captivate was on 7/27/10, this was printed on the battery at least. The AT&T rep gave me just a new phone while using my same battery, how can I check the build date of the phone with the serial number? I've seen mention of this somewhere on these forums about a link at Samsung that will tell me
Edit: Figured it out, it's under the Samsung product registration, when you enter your IMEI it tells you the manufacturer date. This one is also 7/27/10... I wonder if it's a common problem with older phones. Can you guys having this problem verify your manufacturing date?

Dropped calls? (Mostly on Edge)

I upgraded from the iPhone 3gs to the captivate about 2 weeks ago. I love the phone and the features, but I definitely have some complaints. I traveled over the weekend to an area that does not have 3g coverage and the Edge coverage is somewhat marginal. Having grown up there and used an ATT cell phone there for about 4 years I know that the service does work ok although data speeds are painfully slow. So heres the deal, my Captivate dropped about 30 calls or more over the course of 2 days, it dropped calls in places where I know my iPhone would certainly hold a call and have decent call quality. I have had 3 Samsung phones in the past and have had trouble with the signal strength on all of them compared to similar phones on other manufacturers. The call problems are absolutely unacceptable to me and have me thinking about returning the phone to ATT this weekend. Has anyone else had this happen to them? Also I do experience more dropped calls even in the 3G area around my house. Any input is greatly appreciated.

Could be a network issue. I have been using Captivate since about the day of launch (bought on 2nd day of release), and may have had like less than 5-6 dropped calls.
And, I have been on EDGE, and not 3G from like after 2 weeks of buying the phone.
Try getting ur piece replaced. Since mine was in the early lot, I replaced mine within 2 weeks, but that was due to poor batter performance. Calls were good on both the pieces. Maybe u got a bad piece, or, in all possibilities, have network issues.

[Q] Should i buy - antenna issues?

I was going to buy the Razr M but after doing some research it seems that it was plagued by GSM and wifi antenna issues. I cant seem to find any info online regarding the antennas on the Razr I, does anyone out there know if the Razr I suffers from the same issues or is it likely to be more reliable?
Any info/help would be gratefully received, I am about to make the big leap from dumb to smart phone and need all the help i can get - everyone i know here just tells me to get a samsung, but i am interested in something with a little more quality and maybe not so high specs.
Thanks...

Don't get a Samsung, I'll tell you that much. I've been using a Razr I on att for majority of the year now, and I've found the antenna to be... Adequate. I get a lot of dropped calls and sometimes texts don't come in until hours after they were sent. Still, this seldom happens. And, I think the crappy cell service in my area is largely to blame. I would still recommend it. This phone is quite speedy, ang the battery is absolutely phenomenal.
Sent from my XT890 using xda app-developers app

Thanks for the info, i also live in an area with poor signal, currently i have to walk out to my gate to send a text. I was hoping to get one with a good antenna so maybe i could text from indoors. (occasionaly my old nokia will text from inside). That was why i looked at motorolas in the first place because they are supposed to have the best antennas. maybe i should think about the dreaded ifone, yuk.
I was prepared to live with the crappy camera and ****ty speaker, but this may be a deal breaker for me, although there just are no other phones i know of with these specs in this size.

Look for a cellphone repeater. This will allow you to use any cellphones in your house without any problem, as long as you choose the right one for your application.