Cell coverage for iPad data AT&T or Verizon. While on air

agidi

agidi

Filing Flight Plan
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Feb 5, 2013
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CapTonka
Hello guys, I've seen some old posts on this topic, and would like to consult this year with updated information.

I fly international mostly vfr in and out of Texas into Mexico and vs.
Since iPads now take any sim I have a pay as you go chip for TELCEL which is the largest coverage provider in MX

And was looking to buy a pay as you go chip from either verizon or AT&T.

Which altitudes have you noted you still have data coverage on your personal phones? Which carrier do you use?
Which do you recommend?

All comments and suggestions are welcomed.
 
I have had both an AT&T and Verizon 3G/4G iPad. I have never received useful data coverage in-flight at any altitude in the Atlanta or DC areas. I know others have posted that they can do it, but it was at best hit or miss for me. If I flew with data turned on I might get nothing for ten minutes, then a NEXRAD update once, and then nothing for 30 minutes, or a partial image, or something like that. Now I don't even turn it on in flight.

Then again, I've never had much success sending a "arriving in 15 min" text from my phone, either, even at 3-5k AGL in an area which would have good coverage on the ground.
 
Ted,

It's my understanding that if you're seeing too many towers then you get locked out. Hence the reason that in-air cell service is typically better in rural areas than urban. That may have been an analog thing though.

I can text on my phone and datalink in ForeFlight on the ipad almost anywhere in rural Missouri below 6000' or so.
 
Also worth noting that it probably depends on your plane. In my low-wing, with the tablet low on my lap, it's got a lot of metal between the antenna and the ground. In a high-wing, especially if you have a suction-mount to the side window or similar, you might get a much better line of sight.
 
Usually don't see any useful data coverage in flight at any altitude. Text messaging is about it.


Sent from my iPad using Tapatalk
 
In Texas from klrd to ksat, khyi, kaus at 7500ish
I get cell and data coverage from AT&T around 70-80% of the time, and I know the no coverage spots are the same that when I drive that route and my cell drops from 4g to edge.
I have not tested verizon in that area.
 
denverpilot said:
Usually don't see any useful data coverage in flight at any altitude. Text messaging is about it.
Click to expand...

That's been my experience too. And the messages need to be a small number of bytes. Sending a MMS picture likely won't work.
 
I have also found that if i leave my phone or ipad cellular service on during flight, my battery can literally drain in a few hours. It goes into constant search mode when dropping in and out of service and bouncing between towers.
 
Shawn said:
I have also found that if i leave my phone or ipad cellular service on during flight, my battery can literally drain in a few hours. It goes into constant search mode when dropping in and out of service and bouncing between towers.
Click to expand...

yup... I recently updated my printed checklist to include portable electronic things, including turn off cell data ..
 
My tablet doesn't have cell service, but I can data-tether it to my cell phone which is plugged into the power adapter. So what ends up eating the tablet power is having GPS turned on.

My cell phone has Verizon service. I had intermittent data service at 4000 MSL over central Texas. It was much more reliable near Dallas or other big cities.
 
Verizon, Sprint, and a few smaller carriers use CDMA radios. AT&T, T-Mobil, and most other carriers use GSM.

CDMA tends to carry over a longer distance so they can serve a larger area with fewer towers. That's why Verizon tends to do better in more remote areas, I chose Verizon for that reason. Most places I go I get 4G service on Verizon where I couldn't even get 3G when I was on AT&T. But I've seen spots where I got nothing on Verizon but AT&T had 3G service with full bars.

So you need to figure out who has good coverage in the parts of the country you spend a lot of time, but in general I find Verizon is better in remote areas/in the air.
 
IT has very little to do with the number of towers and all to do with the fact that they're designed not to waste radiation in a direction (upward) that they don't expect people to be legitimately using it.

GSM is a standard not a modulation mode as CDMA is. Really a collection of standards and not just for the modulation schemes but also how subscriber information is managed in the hope of making a system-independent handset. While the original 2G GSM was TDMA the 3G (UTMS) is CDMA as is the 4G LTE be it from the GSM-ish carriers like AT&T and T-Mobile or form Verizon is neither, it's a newer scheme called OFDMA.

The modulation scheme has little to do with coverage. It's mostly network design (placement of the towers, etc...). It's hard once you're off the major carriers to even tell what you have. The DSP in the phones typically can handle any of these and it's really a programming issue to determine where you're getting your bandwidth from.
 
Here in a well populated area of South Florida I was told that I would get 4G service. In fact I get nothing at home most of the time! Drive a short distance down the road and I get coverage. Sprint gave me a box that pugs into my WiFi and needs GPS to provide the service, and most of the time that is useless because it cannot pick up the GPS signals that my tablet does!
 
I don't have a data plan for the Ipad but I do have an AT&T Iphone. I get fine coverage all over Northern California, although it starts dropping above 7K typically. Other than that, no issues.
 
flyingron said:
IT has very little to do with the number of towers and all to do with the fact that they're designed not to waste radiation in a direction (upward) that they don't expect people to be legitimately using it.

GSM is a standard not a modulation mode as CDMA is. Really a collection of standards and not just for the modulation schemes but also how subscriber information is managed in the hope of making a system-independent handset. While the original 2G GSM was TDMA the 3G (UTMS) is CDMA as is the 4G LTE be it from the GSM-ish carriers like AT&T and T-Mobile or form Verizon is neither, it's a newer scheme called OFDMA.

The modulation scheme has little to do with coverage. It's mostly network design (placement of the towers, etc...). It's hard once you're off the major carriers to even tell what you have. The DSP in the phones typically can handle any of these and it's really a programming issue to determine where you're getting your bandwidth from.
Click to expand...
Not too bad of a description. But let me correct a couple of things.

CDMA is NOT A modulation scheme it is an access method.

CDMA = Code Division Multiple Access

In the TIA IS-95 based telecom standard for CDMA the modulation is Quadrature Phase Shift Keying (QPSK)

For 'GSM' It is uses Time Division Multiple Access (TDMA) and the primary modulation is Gaussian Minimum Shift Keying. (GMSK) based on FSK.

Also, small typo. UMTS not UTMS. AKA UTRA and LTE is AKA a eUTRA. And yes 3G for GSM systems used a Wideband CDMA (W-CDMA). Not the same CDMA as IS-95 based, but the same underlying theory. There was a lot of commonality to allow chip architectures to have common modules to make dual technology chips cheaper.

Also FWIW LTE is only OFDMA on the Downlink the uplink is SC-FDMA. LTE (eUTRA) supports adaptive modulation techniques for link coding, just like 3G WCDMA did. In LTE we are talking about adding 256QAM for a supported modulation rate in small cells. Macro cells can support 64QAM.

Another also. For all of these technologies and their use in telecom, they are all collections of standards. LTE, GSM, WCDMA are all handled by 3GPP and IS-95 based CDMA was handled by 3GPP2. I have or am currently working in both groups.
 
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denverpilot said:
Usually don't see any useful data coverage in flight at any altitude. Text messaging is about it.


Sent from my iPad using Tapatalk
Click to expand...

Same here, but I do consistently get text coverage at or below 3000 in west Michigan with verizion, so I turn it on during near approach and use it to let people know how far from the airport I am if they are expecting me.

For what its worth, I also noticed if my ipad is linked up to my stratus (wifi) and have cellular coverage at the same time it will drop one or the other occasionally, so in my preflight I make sure to turn cell phones on airplane, turn off cellular on ipad and confirm wifi is hooked to stratus.
 
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