Purchase US GSM phone for use in Germany?

[djinks]

I thought I might like to have a mobile phone for my next trip to Northern Germany. I'm confused by the different frequencies, when each is needed etc. I will most likely purchase a Tschibo SIM when I arrive and I can see two scenarios for use of the phone:

1 - a little voice, but mostly a monthly 5GB data pack that I can share with my O2 surfstick and laptop
2 - Use VOIP and no voice minutes on the Tschibo SIM, swapping the SIM to the surfstick for laptop sessions

Being confused about the radio frequencies, here is my question:
What would be the limitations of these above approaches if I brought an unlocked (US) T-mobile 4G with me. Would an AT&T phone be better? I mention them because I can pick one up easily at a moderate price on Craigslist.org. My initial research suggests the 2100 frequency is common with the O2 and (US) T-mobile phones, but I have also read that other frequency ranges will also be necessary for higher data speeds (~3.5mbps).

Looking at the charts on this page, it appears that both ATT and T-mobile US phones are missing one of the two frequency ranges required for high-speed data in Europe. AM I right?

[dg7feq]

Originally Posted by djinks

I thought I might like to have a mobile phone for my next trip to Northern Germany. I'm confused by the different frequencies, when each is needed etc. I will most likely purchase a Tschibo SIM when I arrive and I can see two scenarios for use of the phone:

1 - a little voice, but mostly a monthly 5GB data pack that I can share with my O2 surfstick and laptop
2 - Use VOIP and no voice minutes on the Tschibo SIM, swapping the SIM to the surfstick for laptop sessions

Being confused about the radio frequencies, here is my question:
What would be the limitations of these above approaches if I brought an unlocked (US) T-mobile 4G with me. Would an AT&T phone be better? I mention them because I can pick one up easily at a moderate price on Craigslist.org. My initial research suggests the 2100 frequency is common with the O2 and (US) T-mobile phones, but I have also read that other frequency ranges will also be necessary for higher data speeds (~3.5mbps).

Looking at the charts on this page, it appears that both ATT and T-mobile US phones are missing one of the two frequency ranges required for high-speed data in Europe. AM I right?

you need 3G 2100 MHz for high speed data usage and 900/1800 MHz for 2G (voice/EDGE) coverage. If you only have 3G you will have many network gaps.

Chris

[inquisitor]

Today nearly all GSM/UMTS phones (especially smartphones) sold in the US support quadband GSM, so in Europe voice telephony and smallband data will definitely work anyway. But when it comes to high speed data you need a phone supporting UMTS/HSPA at 2100 MHz, which is the only frequency band used for 3G in Germany while some other European countries have already deployed UMTS/HSPA to the 900 MHz band, too. So for Germany a 2100 MHz-capable 3G phone will do it.
In contrast AT&T run their 3G network at 850 and 1900 MHz and T-Mobile USA at 1700/2100 MHz (so-called "AWS"-band which is not compatible with the European UMTS 2100 MHz band as it uses different uplink frequencies).
AT&T and T-Mobile both sell phones that support at least UMTS 2100 besides their own frequencies, so you buy your phone from any of them. Just make sure it definitely supports UMTS 2100. Also be aware that some phones are sold with different frequency configurations throughout the world, so always check the specifications on the box!
For example the HTC Desire has been produced in three different versions:
900, 2100 MHz for Europe
850, 1900 MHz for North America (e.g. Telus Mobility Canada)
850, 2100 MHz for Telstra Australia

Or the Samsung Nexus S in two versions:
900, 1700/2100(AWS), 2100 MHz for Europe and T-Mobile USA
850, 1900, 2100 MHz for North American operators with UMTS 850 and UMTS 1900 networks like AT&T

The T-Mobile mytouch 4G supports the AWS-band (1700/2100) and the European 2100 MHz band as well as all global GSM frequncies (850/900/1800/1900 MHz), so it would work on T-Mobile USA and on all German networks.
By the way Lidl is way cheaper than Tchibo while giving absolutely the same service (both are on the O2 network).

[djinks]

Great! Thanks for your (as always) comprehensive response. Looks Like I will acquire a T-Mobile My-Touch 4G before my next trip. Also thanks for the mentioning Lidl.

[Charlie]

Originally Posted by inquisitor

Today nearly all GSM/UMTS phones (especially smartphones) sold in the US support quadband GSM, so in Europe voice telephony and smallband data will definitely work anyway. But when it comes to high speed data you need a phone supporting UMTS/HSPA at 2100 MHz, which is the only frequency band used for 3G in Germany while some other European countries have already deployed UMTS/HSPA to the 900 MHz band, too. So for Germany a 2100 MHz-capable 3G phone will do it.
In contrast AT&T run their 3G network at 850 and 1900 MHz and T-Mobile USA at 1700/2100 MHz (so-called "AWS"-band which is not compatible with the European UMTS 2100 MHz band as it uses different uplink frequencies).
AT&T and T-Mobile both sell phones that support at least UMTS 2100 besides their own frequencies, so you buy your phone from any of them. Just make sure it definitely supports UMTS 2100. Also be aware that some phones are sold with different frequency configurations throughout the world, so always check the specifications on the box!
For example the HTC Desire has been produced in three different versions:
900, 2100 MHz for Europe
850, 1900 MHz for North America (e.g. Telus Mobility Canada)
850, 2100 MHz for Telstra Australia

Or the Samsung Nexus S in two versions:
900, 1700/2100(AWS), 2100 MHz for Europe and T-Mobile USA
850, 1900, 2100 MHz for North American operators with UMTS 850 and UMTS 1900 networks like AT&T

The T-Mobile mytouch 4G supports the AWS-band (1700/2100) and the European 2100 MHz band as well as all global GSM frequncies (850/900/1800/1900 MHz), so it would work on T-Mobile USA and on all German networks.
By the way Lidl is way cheaper than Tchibo while giving absolutely the same service (both are on the O2 network).

inquisitor,

I know this is a very old thread.

The more I read about cell phone compatibility, the more confused I am!
I've been reading a lot of your posts and you've been very helpful.
I'm thinking of planning a trip to Europe in the next several months, and trying to find out if my T-mobile Samsung Galaxy S2 will work in several countries(including Germany) with local sim cards.

I plan to get the unlock code from the carrier soon.

On Wiki for the S2 this is what is listed for networks:
1,900 MHz;
WiMAX 2.5 to 2.7 GHz;
802.16e 2.5G (GSM/GPRS/EDGE): 850, 900, 1,800, and 1,900 MHz
UMTS: 850, 900, 1700 (T-Mobile USA only), 1,900, and 2,100 MHz
HSPA+: 21/42 Mbit/s; HSUPA: 5.76 Mbit/s LTE 700/1,700 Rogers Only.

What I find confusing is that they list the UMTS 2,100 MHz, which you say will work, "So for Germany a 2100 MHz-capable 3G phone will do it."

But you also said in the above post that the AWS band 2100 MHz is not the same as the European 2100 MHz! Wiki does not specify.

So what I'm really asking is if this phone will work in most European countries with local carrier sim cards with these frequencies for voice and data,
UMTS: 850, 900, 1700 (T-Mobile USA only), 1,900, and 2,100 MHz.

I hope I didn't confuse you with my confusion

[DRNewcomb]

For some reason many people find UMTS frequency bands very confusing. Cellular phones don't work on one specific frequency (e.g. 1,800,000,000.00 Hz). Rather, they work in bands that cover many megahertz (e.g. 1710-1785 & 1805-1880 MHz). These bands are commonly referred to by the approximate frequency they occupy. In the case above it's "1800 MHz" even though that exact frequency is not included in the band. Without getting in too deep and further confusing you, lets just say that UMTS band IV (a.k.a. AWS) is different from and not compatible with band I (a.k.a. 2100) even though there is some overlap in the frequency ranges.

If unlocked, your phone should work very well with a local SIM in Europe.

[inquisitor]

The most common UMTS frequency band in Europe is called UMTS2100 or UMTS frequency band I and uses 1920-1980 MHz for the uplink and 2110-2170 MHz for the downlink. Some European operators additionally use UMTS900, however none of the German ones.

AWS which is also known as UMTS1700, UMTS1700/2100 and UMTS frequency band IV uses a way lower frequency for the uplink (1710-1785 MHz) but shares a subset of the UMTS2100 downlink frequency range for its downlink.

For an overview of UMTS frequency bands see UMTS frequency bands - Wikipedia, the free encyclopedia

The overlapping downlink frequency ranges of UMTS2100 and AWS facilitate the integration of UMTS2100 in AWS-handsets. So most AWS handsets also support UMTS2100, but not the other way around.

According to Wikipedia and several other sources the T-Mobile USA version of the Galaxy S2 (also know as SGH-T989) supports UMTS2100:

The cellular radio of the T-Mobile supports UMTS bands I (2100 MHz), II (1900 MHz), IV (1700 MHz) and V (850 MHz).

So the Samsung SGH-T989 will work in Europe provided that it is unlocked.

[inquisitor]

Originally Posted by DRNewcomb

For some reason many people find UMTS frequency bands very confusing.

What confuses people is AWS because of the huge offset between its uplink and downlink frequencies, so neither calling it UMTS1700 or UMTS2100 or UMTS 1900 (which is approximately the middle between up- and downlink) gives you an idea of the actually used frequencies. And when youc call it UMTS1700/2100 people may think you refer to two different UMTS frequency bands.

[Charlie]

DR, thanks for the fast reply!
Not to sound stupid, but are we talking about the same thing?

This is my first smartphone, and it is amazing, but people talk about root,sim card unlocking etc.
What I'm talking about is getting the the code so that I can use other carriers sim cards without a hardware/firmware modify leaving the phone stock.
So this will work, and allow me to use my T-Mobile card when I return home to the US like normal?

Excuse my ignorence.

[inquisitor]

What you need to make sure is that your phone does not have a so-called SIMlock or netlock, which prevents your phone from accepting another SIM card or SIM cards from other operators respectively. Removing such SIMlock or netlock is called unlocking and has nothing to do with rooting or firmware modifications. Also unlocking does not impact its functionality on your home network, onto which it might be locked.