[zohirul]

Hello,
I have read many threads about T-Mobile 3G networks' uncompatibiliy with the iPhone 3G because of the frequency issue as everybody was pointing out that T-Mobile uses 1700 MHz for 3G network. (So far I have understood from different comments)

Please check out the 3G frequency of T-Mobile from the following link and you will see that T-Mobile will also use 2100 MHz freq. for 3G.

3G FAQs

And from the iPhone 3G spec(following link). you can see under the "Cellular and Wireless" division, iPhone supports UMTS/HSDPA (850, 1900, 2100 MHz).

Apple - iPhone - Technical Specifications

Then why shouldn't iPhone 3G support T-Mobile's new 3G network?

Can somebody please explain?

[freakoftheindustry]

If you want to hear it from the horses mouth, your best bet is to call Tmobile and ask to speak with a network engineer and have them explain to you how 3g networks are built.

[seh6183]

2100, sadly, is only in Europe, Africa, Asia, Oceania and Brazil.

Unless someone releases software that can make the 3g iphone look for 1700mhz... We are screwed.

[ausdhnj]

The 3G technologies used by both AT&T and T-mobile are different. For the lack of a better example, its like T-mobile speaks german and AT&T speaks english. Also, T-mobile 3G uses 1700 MHz to upload and 2100 MHz to download. iPhone doesn't support 1700 Mhz.

One possibility is to get the iPhone to work with T-mobile 3G is to make it compatible with T-mobile's 3G technology (if allowed by software hack) and to make it upload via edge and download via 3G.

[seh6183]

I don't think that statment is entirely true about uploading and downloading and using different frequencies. I do no believe that there is any 2100 at all in the US.

[ausdhnj]

Originally Posted by seh6183

I don't think that statment is entirely true about uploading and downloading and using different frequencies. I do no believe that there is any 2100 at all in the US.

Back in 2006, T-mobile spent $4.2 billion to buy AWS Spectrum from the FCC. T-mobile currently uses duel, tri, and quadband phones (850/900/1800/1900 MHz). The spectrum purchased in 2006 was a combination of 1700 MHz and 2100 MHz, and these are the frequencies that T-mobile using for their 3G. In order for T-mobile to use their AWS (1700/2100 MHz) spectrum, they will role out 3G on WCDMA IV, with information uploaded on 1700 MHz and downloaded on 2100 MHz. The combination of 1700 MHz and 2100 MHz is necessary for data or voice to transfer through 3G. Because of the need for this combination of 1700/2100, no unlocked 3G phones work with T-mobile's 3G. Even phones with only 1700 MHz, or only 2100 MHz will not work because of the need for the other AWS band.

T-Mobile 3G - TmoNews Wiki

[zohirul]

ausdhnj replied with a very useful information which make good sense. It would be better than nothing if we could at least use the 2100 MHz for downlink and EDGE for upload, but I think this won't happen.

Anyway, thanks for the replies.

[461am]

The infineon chipset in the iPhone is capable of using the 1700 Range, however this fact, for reasons unknown, is omitted from the iPhone spec sheet.

This opens up the possibility of it working with some clever hackery.

[ausdhnj]

Originally Posted by 461am

The infineon chipset in the iPhone is capable of using the 1700 Range, however this fact, for reasons unknown, is omitted from the iPhone spec sheet.

This opens up the possibility of it working with some clever hackery.

Knock yourself out: Chip set link