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2014-12-14, 18:54 #1
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- Dec 2014
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Android and carrier frequency reports
OK, this might be pushing the limits of this forum, but I know that the people here are the best!
I am in International traveller on business, and while in Chiang Mai Thailand, I picked up a nice, new, unlocked Zenfone 4 at the mall there. I want a world-class GSM phone and so I carefully chose a model (of many brands) that fit my requirements in Android OS and other features and had the right frequencies to work in the bands of Europe, Asia, and the USA. The phone worked well with local SIM card carriers in Europe, Thailand, Singapore, Phillipines, Australia. But upon re-entry into the USA -- wham! Total failure to connect to any towers using ATT and later trying TMobile service. I even had the local ATT store check the APN programmed values for their carrier service. Didn't work.
So to be clear.... no bars of service anywhere. Emergency phone calls only.
OK.... so then a nice eBay store informed me that Asus company (maker of Zenphones) says they never sell the correct version of the phone for the USA. The frequencies are missing for USA! This is contrary to what the shopkeepers said (in broken English of course) at the time of sale, since I was savvy enough to check for this. Obviously the placards at the store telling the specs and frequencies were not correct, but the phone obviously works in Thailand.
To be sure, I was not out a lot of money here: $103... and I still have a phone that works while I travel. I just wanted something that also worked in the USA and on the cheap.
Question: Is there a way by Android app or by the Android OS itself to interrogate any Android phone and know for sure what frequency bands are supported by the phone itself, in advance, while you are in the store for purchase? You can get any number of additional specs out of the "settings" menu of the OS, but I can't find anywhere that states the frequencies actually supported by the given handset. If we had a way to do this, then purchasers while traveling could get some great deals on their phones, and be assured that things are going to work back in the USA as well (or at least stand a good chance of working).
2014-12-14, 19:44 #2
If we had a way to do this, then purchasers while traveling could get some great deals on their phones
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- Feb 2013
- Mojave Desert CA
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Unfortunately I don't know the answer to your question about frequency's but the android forums might be a place to look if someone on this forum doesn't know.
2014-12-18, 15:24 #3
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- Mar 2010
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Yes, MUST buy "*4* frequencies" cell phone. "3" frequencies are not enough. THEN also to ask for encoding support such as GSM ,CDMA, TDSMA.
Some phones list the 4 frequencies on a label under the battery. (Need to remove lid, then remove battery to see the label.)
Even then, today, you still need to 'match' encoding methods. GSM is almost universal. CDMA is not. CDMA is primarily used by Verizon. The GSM card in Verizon cell phone is for data (read: Internet). Only GSM provides the quicky, improving data transmission methods (3G and 4G today). Apple tablet/cell phone of Verizon branding carries both CDMA and GSM, CDMA for phone service and GSM (G3 or G4) for data plan.
Unless your phone supports all *4* frequencies, AND all encoding modes (GSM, CDMA, GSM/CDMA/TDSMA in China), you may have a problem in parts of the Earth.
Because wireless transmission circuits are hardware (tuned to the specific frequency), then firmware/hardware for the encoding, OSes, such as Android, Linux, Windows, cannot help.
So it is not just the transmission frequency, it is also the encoding method.
In addition, check whether the cell phone is 'locked': can only talk to specific carrier. Usually, it is easily unlocked. T-mobil, when asked, will unlock their phone.
The best place to buy 'unlocked almost universal cell phone is HongKong and Australia.
Usually a legit shop (not one in the back alley) will sell you the correct phone if you emphasize 'must work in USA *with Verizon* and in EU', or ask for '4-frequency capable'. EU and China are almost all GSM.
It is USA carriers that make things complicated.
2014-12-18, 15:35 #4
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- Dec 2009
- Rochdale, UK
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