US iPhone 3G Only Designed for AT&T?

[MacBytes]

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Category: Apple Hardware
Link: US iPhone 3G Only Designed for AT&T? (http://www.macbytes.com/link.php?sid=20080612095759)
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Posted on MacBytes.com (http://www.macbytes.com)
Approved by Mudbug

[Mudbug]

If this is indeed true, doesn't it mean that a US iPhone 3G would not work if you took it across the pond and tried to use it on a european network since it's a different bandwidth?

[pederg]

No, because the iPhone 3G is still tri-band, which means that it works in nearly all countries.

When looking at the specification for the US iPhone 3G (here), on can read "...2100 MHz".

in Europe the 3G network is the 2100 MHz bandwidth

[daveschroeder]

If this is indeed true, doesn't it mean that a US iPhone 3G would not work if you took it across the pond and tried to use it on a european network since it's a different bandwidth?

If you read the linked article:

The specification of the iPhone 3G has been designed to fit with the largest number of carriers worldwide, and especially for countries were such networks are massively developed.

The headline is a bit misleading...they're asserting that the AT&T might be the only 3G carrier *in the US* that is fully compatible with the iPhone. But the iPhone WILL roam on GSM networks, and will also work on the vast, vast majority of 3G networks worldwide.

[cazlar]

Just not on T-mobile USA (3G), which has a "non-standard" frequency. 2G/EDGE should continue to work though.

[iVoid]

So T-Mobile 3G is 1700/2100.

iPhone supports 2100, wouldn't it work? Or is the 1700 used in some parts of t-mobile's 3G network and 2100 other parts?

[phairphan]

Of course, this is all rather academic until T-Mobile actually turns on their oft-delayed 3G service.

[mkrishnan]

So T-Mobile 3G is 1700/2100.

iPhone supports 2100, wouldn't it work? Or is the 1700 used in some parts of t-mobile's 3G network and 2100 other parts?

I don't understand the specifics, but a number of posts I've seen seemed to state that the 2100 MHz spectrum used by T-Mobile USA and the 2100 used for 3G in Europe are somehow not the same... so it was not (never) expected to work with T-Mobile USA, just like most other existing tri-band HSPA phones. But I've yet to find a clear explanation of what differs between the "Band IV" 2100MHz used in the US and the 2100MHz used in Europe. So far, the best explanation I can find is that the system actually uses 1700 and 2100 simultaneously (up at 1700 and down at 2100), which means that even though there is a 2100MHz radio in the European phones, they won't work on this network in 3G without the 1700 radio.

http://mobilesociety.typepad.com/mobile_life/2007/03/3g_licensens_of.html

On the other hand, from what I have been able to gather, Band IV (1700/2100) will be increasingly important, because a number of countries in the Americas besides the US intend to use it for 3G as well, so it may become less of an issue in a couple of years as other providers in other nations deploy Band IV 3G....

[SirOmega]

UMTS Frequency Bands (http://en.wikipedia.org/wiki/UMTS_frequency_bands)

You can see that band IV uses 1700mhz up and 2100mhz down. The Euro UMTS2100 (band I) uses 1900mhz up and 2100mhz down. Its likely the 3G iPhone wont work with the 3G T-Mobile network.

[EricVollnogel]

Perhaps I didn't understand what was being pointed out in the original post regarding 3G, but to set the record straight (I've been a cell phone nerd for years), these are the facts as I understand them:

According to Apple's website (http://www.apple.com/iphone/specs.html), the 3G iPhone operates on the following cellular frequencies:

UMTS/HSDPA (850, 1900, 2100 MHz)
GSM/EDGE (850, 900, 1800, 1900 MHz)

Not to get technical, but these are basically frequency ranges, which in themselves are provisioned out.

Although there are lots of different frequency ranges for GSM and UMTS, in reality there are only a few that are used in the real world. For GSM, 850 and 1900 MHz are used in the USA (1900 is much more popular, however AT&T does use 850 in some locations) and 900 and 1800 are used in most of the rest of the world (1800 is much more popular). Both iPhones support all four of these frequencies.

The same goes for UMTS (HSDPA). In most of the world, 3G is being deployed in the 2100 MHz range. Anyone who travels to Japan, for example, knows they have to have a 3G phone because only 3G on 2100 MHz is supported. There is a small cellular company in Japan which only uses 1700 MHz GSM, but they are an offshoot. In the USA, currently part of the spectrum in the 850 and 1900 MHz bands are used for UMTS -- the same bands used for GSM.

The iPhone 3G (just like other AT&T 3G phones) will do phone, sms, and data just fine here in the USA and abroad.

Although T-mobile is working on 3G, they have not deployed it yet. In the USA, the only carriers that support 3G to my knowledge are:
AT&T 850/1900 MHz and Cordova Wireless Communications 850 MHz although others are planned (some using 1700 MHz and/or 2100 MHz).

So, in conclusion, the iPhone 3G will work in the USA and the rest of the world on GSM and UMTS/HSDPA. My wireless card (with the same supported frequency ranges) already does now.

On the other hand, if you buy an iPhone 3G in the USA and try to jailbreak it for use with T-Mobile, it won't work -- T-Mobile doesn't have 3G yet. But when they get it, if they decide on 1700 MHz, it obviously won't work on their network, but is that an issue?

Just my 2 cents.

[RubberShoes]

So what you're saying is even though a network owns both bands (850 and 1900 MHz for example) they mainly use the higher frequency and use the lower only as a backup where the higher isn't available?

Or is the upload on the lower band, and the higher used for the download?

[EricVollnogel]

I don't understand the specifics, but a number of posts I've seen seemed to state that the 2100 MHz spectrum used by T-Mobile USA and the 2100 used for 3G in Europe are somehow not the same... so it was not (never) expected to work with T-Mobile USA, just like most other existing tri-band HSPA phones. But I've yet to find a clear explanation of what differs between the "Band IV" 2100MHz used in the US and the 2100MHz used in Europe. So far, the best explanation I can find is that the system actually uses 1700 and 2100 simultaneously (up at 1700 and down at 2100), which means that even though there is a 2100MHz radio in the European phones, they won't work on this network in 3G without the 1700 radio.

http://mobilesociety.typepad.com/mobile_life/2007/03/3g_licensens_of.html

On the other hand, from what I have been able to gather, Band IV (1700/2100) will be increasingly important, because a number of countries in the Americas besides the US intend to use it for 3G as well, so it may become less of an issue in a couple of years as other providers in other nations deploy Band IV 3G....

Multiple frequency ranges, i.e. 1700 and 2100 above are NOT used simultaneously. As reception changes, it is possible that the device will look for another frequency range to use, but discreet traffic (upstream and downstream) are both within the same frequency range.

The topic of how frequencies and time slices are assigned and multiplexed is too large for this discussion (I would suggest reading a white paper on the topic for those interested), but suffice it to say that basically after the device (handset) is validated on a network, it is given a modulation and slice scheme to use. This scheme is going to be in one frequency range only.

[SirOmega]

As reception changes, it is possible that the device will look for another frequency range to use, but discreet traffic (upstream and downstream) are both within the same frequency range

Thats not what the WP link I posted above says - it says that T-Mobile is allocated the AWS band which indicates upstream (phone to cell tower) in the 1700MHz band, and from tower to phone in the 2100MHz band.

[EricVollnogel]

Thats not what the WP link I posted above says - it says that T-Mobile is allocated the AWS band which indicates upstream (phone to cell tower) in the 1700MHz band, and from tower to phone in the 2100MHz band.

I'll be dammed! Of course you're right. I did some further research that backed up your assertions. I inaccurately assumed that the "band" naming, i.e. 1900 MHz was similar to GSM. In GSM the the UL and DL frequency ranges are within or pretty close to the naming, but apparently they've diverged from that practice for 3G.

It's unfortunate, I think, because unlike GSM which is pretty ubiquitous, it's going to make it difficult for device manufactures to build handsets that are going to support all the frequency schemes.

Very surprised indeed.

[mkrishnan]

EDIT: never mind. It happens. :)

P.S. FWIW, GSM has ... four... bands as well. ;) It only uses one at a time, but it isn't the same frequency everywhere. Once HSPA is common, it's fairly likely there'll be quad band HSPA radios, and 3G phones will be completely intercompatible, but that may take some time.

[RubberShoes]

So what's our verdict here?

iPhone 3G only works on ATT's 3G? There's no compatibility between the 1900 and 2100MHz 3G frequencies?

[mkrishnan]

iPhone 3G only works on ATT's 3G? There's no compatibility between the 1900 and 2100MHz 3G frequencies?

No, so far, the verdict is that it works on the traditional 3G bands used in Europe, by AT&T in the United States, and in most of the rest of the world, but not on the band used by T-Mobile in the US and in the process of implementation in other countries in the Americas.

[smartdog126]

and also there making teh 3g iphone not to be unlocked there making you activate it in stores within 30 days