Anyone who understands this "spectrum" 3g AT&T Tmob issue more than I.... I have a ?

[wick12345]

Anyone who understands this "spectrum" 3g AT&T Tmob issue more than I.... I have a ?

Okay so here it goes....

WTF!!!!!!!!!!!???

So I've been reading all day to understand this and I do get how we ended up screwed on 3g from the rest of the world

Tmob is on "aws" which is sort of a halfway between 2100/1900 of Europe at 2100/1700

AT&T is on 1900/850 or 850... I couldn't find a straight answer on that.

Now everyone says this is "hardware" in the phone that dictates this issue. I've been researching (this is where I could use your help) and I'm missing something. Nexus one is using Qualcomm Snapdragon™ 3G QSD8250.... This AMAZING chip is not only the processor but the 3g chipset as well... (correct?) Yet this same chip is in the LG expo and the LG expo has 850/1900/2100 for it's 3g.

It would seem to me... (a simple man) that Qualcomm would NOT produce separate chips but would use some firmware/software to let the chip determine which frequencies to use. Otherwise they would have to stamp out more than one chip instead of just having one factory.

The other major issue I see is antenna length is a physical characteristic based on the radio wave you are trying to receive/send. So that may have to change too but that's more about being optimum than impossible.

Not that anyone has the cash for this but what would stop someone with REALLY amazing soldering skills from switching the two supposedly identical chipsets? Would that extremely silly idea work?


Just a thought that I thought a few people on this forum may understand more than I do.

 

[student.driver]

First, the radio ROM should be the one to dictate what frequencies are supported if the radio chip can support multiple frequencies, which it does. There is a soft radio chip from Samsung (I think it's Samsung) that can be reprogrammed to change which carrier it's supporting, but I haven't read of it being used yet. I believe that's the future, but currently you get a chip that almost universally supports European 3G and quad-band GSM w/EDGE out of the box, and then *one* set of US/Canadian frequencies. That's it.

WIND (new Canadian carrier) is using the same AWS spectrum as T-Mobile US is, so that should give more "pull" for more AWS support in future handsets, but with T-Mobile moving toward a "dumb pipe" arrangement (no annoying a la carte options, no music services, no stupid "extras" to pay for, just voice/data/text plans) the hope is more devices will be available in the open market that will just work on T-Mobile and support whatever you're paying for. Since your ISP is just "there" and "supports" (ish) whatever you're using, the hope is T-Mobile US will set the trend for that behavior here, and WIND might be going the same way in Canada, and FINALLY bring this mentality to North America.

If that works out, expect to see more soft radio chips and ROMs to come out with these handsets so they can be "flipped" from network to network and still support all the data and voice options. If it doesn't (I think it will to some degree), then expect the long and annoying tradition of vertically integrated handset and carrier support where the handset has to be "made" to support whatever options the carrier chooses (for compatibility and being as cheap as possible to make) and not have full, cross network support for devices.

 

[Casao]

Softchips aren't common and won't be. You could probably swap the chips directly, but it's going to cause issues.

T-Mobile uses AWS, which is 1700/2100 for down/up stream. It's considered GSM band 4, which is different from Europe, who uses a 900 band and a 2100 band, both of those are full up/downloads on close bands, so some places use 900, some use 2100, some offer both. It's a bit different. The Nexus One supposed 900/AWS/2100, meaning it's 100% Europe and T-Mobile compatible. We're seeing more and more of these chips since it's significantly simpler than making Euro + AT&T chips.

Motorola is developing a chip with AWS + 850/1900, meaning sometime next year, we should be seeing truly "USA" model cell phones, which will support any US GSM carrier. Euro+USA full could come eventually, but the addition of AWS means it'd take a 5-band chip instead of Quad band like EDGE.

 

[Renarudo]

T-Mobile 3G Upgrade

FCC cleared radio frequencies about 3 years ago, T-Mobile bid on the majority of them and used it to upgrade its network.

Much lulz were had.

Here is a List of UMTS Networks. Pretty much all of Europe uses 2100.

I'll do more research as to WHY, but most carriers opt for certain frequencies because of hardware compatibility and cost effectiveness for when they were upgrading.

That link makes it appear that AT&T is worthless outside of NA, but that's untrue (AT&T has, for the most part coverage worldwide, or so I think...) so I'll do some more research on my lunch break.

 

[nelson8403]

T-Mobile 3G Upgrade

FCC cleared radio frequencies about 3 years ago, T-Mobile bid on the majority of them and used it to upgrade its network.

Much lulz were had.

Here is a List of UMTS Networks. Pretty much all of Europe uses 2100.

I'll do more research as to WHY, but most carriers opt for certain frequencies because of hardware compatibility and cost effectiveness for when they were upgrading.

That link makes it appear that AT&T is worthless outside of NA, but that's untrue (AT&T has, for the most part coverage worldwide, or so I think...) so I'll do some more research on my lunch break.

ATT has some coverage (edge once again) everywhere, some places in canada and australia have 1900, but ATT for the most part is using a freq that's not very universal

 

[GuestK0050]

The issue is the amplifier module.

I have the Rogers G1 running on AT&T 3G. The radio firmware/software is identicle to the T-Mobile/ADP1 phone.

They did a tear down of the G1's and they both use physically different amplifier part numbers. It's not a part from Qualcomm and has nothing to do with their chipsets. Their chipsets do indeed support AT&T's 3G frequencies, if paired with a compatible amplifier.

Now if someone tears down the Nexus One, and gets the part number for the amplifier, and that amplifier can do AT&T frequencies, it may just be an issue of hacking the radio somehow to enable it.

It's quite possible the amplifier on the Nexus One can handle AT&T 3G, but they didn't bother to "certify" it with the FCC because T-Mobile is te launch parter and AT&T is sucking Apples teet.

One can only wait and see. I'm betting it simple doesn't have the correct amplifier for AT&T.

There are amplifiers that work on all frequencies. Why they don't spend the extra dollar or whatever is beyond me. They are literally THAT cheap.

-James

 

[coolVariable]

The issue is the amplifier module.

I have the Rogers G1 running on AT&T 3G. The radio firmware/software is identicle to the T-Mobile/ADP1 phone.

They did a tear down of the G1's and they both use physically different amplifier part numbers. It's not a part from Qualcomm and has nothing to do with their chipsets. Their chipsets do indeed support AT&T's 3G frequencies, if paired with a compatible amplifier.

Now if someone tears down the Nexus One, and gets the part number for the amplifier, and that amplifier can do AT&T frequencies, it may just be an issue of hacking the radio somehow to enable it.

It's quite possible the amplifier on the Nexus One can handle AT&T 3G, but they didn't bother to "certify" it with the FCC because T-Mobile is te launch parter and AT&T is sucking Apples teet.

One can only wait and see. I'm betting it simple doesn't have the correct amplifier for AT&T.

There are amplifiers that work on all frequencies. Why they don't spend the extra dollar or whatever is beyond me. They are literally THAT cheap.

-James

Or sell two (or more) versions of the phone?
850/1900/2100
900/1900/2100
1700/2100

I would guess ... idiocy.
Even more idiotic ... phone manufacturers building phones with NAM 3G frequencies ... but not selling them.

 

[GuestK0050]

It seems the Nexus One at least has the hardware to support AT&T 3G, see my post here.

http://forum.xda-developers.com/showthread.php?t=612950

-James