When I was in India last week, I couldn't get the data connection working. It works in the US and I got it working in London with T-Mobile's help (they took it on and off the network). So, unless I was in a wifi hotspot, I couldn't get email until I got back to the hotel at night. As someone running a small but very global business, that doesn't work well for me. Has anyone else had problems with getting data connections in various places? T-Mobile has no idea why and kept suggesting strange stuff (the signals are too weak -- well all the folks with iPhones had no problems -- or maybe data roaming is turned off). If yes, how did you fix or improve things?

I suspect that TMobile may not have a roaming agreement with the carrier that you connected to.

You also have to make sure your phone supports the right frequency bands.

In the US, 850 and 1900 mhz are used for 2g and voice. The rest of the world mostly uses 900 and 1800. 3g data here is on 1700 and 2100 for tmobile, 850 and 1900 for at&t. The rest of the world mostly uses 2100.

If it worked in London, it should in India (they use the same frequencies) assuming there is roaming agreement.

I was able to get on briefly in Hyderabad, which is in Andra Pradesh (after t-mobile took my phone off the network and then put it back on) but couldn't do the same when I was in Delhi or Mumbai.

FYI:

Here's what t-mobile lists as specs for frequencies for my phone:
GSM: 850; 900; 1800; 1900
UMTS: Yes
Bands: 1 (2100) and 4 (AWS 1700/2100)

Here's what t-mobile lists for roaming partners:

Aircel Cellular [Chennai] 900Mhz N/A
Bharti Airtel Limited [Andhra Pradesh] 900Mhz 2G
Bharti Airtel Limited [Calcutta] 900Mhz 2G
Bharti Airtel Limited [Chennai] 900Mhz 2G
Bharti Airtel Limited [Delhi] 900Mhz 2G
Bharti Airtel Limited [Gujarat] 1800Mhz 2G
Bharti Airtel Limited [Haryana] 1800Mhz 2G
Bharti Airtel Limited [Himachal Pradesh] 900Mhz 2G
Bharti Airtel Limited [Karnataka] 900Mhz 2G
Bharti Airtel Limited [Kerala] 1800Mhz 2G
Bharti Airtel Limited [Madhya Pradesh] 1800Mhz 2G
Bharti Airtel Limited [Maharashtra] 1800Mhz 2G
Bharti Airtel Limited [Mumbai] 1800Mhz 2G
Bharti Airtel Limited [Punjab] 900Mhz 2G
Bharti Airtel Limited [Rajasthan] 900Mhz 2G
Bharti Airtel Limited [Tamilnadu] 1800Mhz 2G
Bharti Airtel Limited [UP West] 1800Mhz 2G
BPL Mobile [Mumbai] 900Mhz N/A
Hutchison Max [Andhra Pradesh] 1800Mhz N/A
Hutchison Max [Chennai] 1800Mhz N/A
Hutchison Max [Karnataka] 1800Mhz N/A
Idea Cellular [Andhra Pradesh] 900Mhz N/A
Idea Cellular [Delhi] 1800Mhz N/A
Idea Cellular [Gujarat] 900Mhz N/A
Idea Cellular [Haryana] 900Mhz N/A
Idea Cellular [Kerala] 900Mhz N/A
Idea Cellular [Maharashtra] 900Mhz N/A
Idea Cellular [UP West] 900Mhz N/A
Spice Telecom [Karnataka] 900Mhz N/A
Spice Telecom [Punjab] 900Mhz N/A
Vodafone Essar [Gujarat] 900Mhz 2G
Vodafone Essar Cellular Limited [Kerala] (Vodafone Kerala) 900Mhz 2G
Vodafone Essar Cellular Limited [Maharashtra] 900Mhz 2G
Vodafone Essar Cellular Limited [Tamilnadu] 900Mhz 2G
Vodafone Essar East [Calcutta] 900Mhz 2G
Vodafone Essar Ltd (Mumbai) 900Mhz 2G
Vodafone Essar Mobile [Delhi] 900Mhz 2G
BSNL 900Mhz,1800Mhz N/A
BSNL 900Mhz 2G
Reliance 900Mhz N/A

So, it's not clear that there should be a problem either with frequency or with roaming agreements.

The only thing I can think of is that my phone, when automatically finding carriers, chose carriers w/o roaming agreements, although I was often on Airtel (which I assume is Bharti Airtel) but was also on Vodafone and Idea.

Your phone will never choose a carrier who doesn't have a roaming agreement with Tmobile because it wouldn't be able to register with the network (it would show "emergency calls only").

The problem is either in how your account is provisioned for int'l roaming (in T-mobile's systems) or in how you've configured your phone.

Go into Settings -> Wireless & Networks -> Mobile Networks

1. Make sure Data Enabled and Data Roaming are checked.
2. Tap Access Point Names, and then edit your selected APN (should say something like "T-Mobile US")
3. APN Settings are:

• APN: epc.tmobile.com
• Server: *
• MMSC: http://mms.msg.eng.t-mobile.com/mms/wapenc
• APN Type: default,supl,mms
• All other options should be blank ("<not set>")

Also, if you don't have an Android-specific data plan, you might experience problems.

hth, gl

thanks, gfunkdave. I will try that.

My phone is doing a few other odd things now that I'm back in the US. It was working fine for a couple of days, but today, I couldn't dial out for a few minutes. It would show the number on the screen and then disconnect. I got busy signals if I dialed the phone. Then, I just went and selected T-Mobile as the network and it started working again. I wonder if there is something wrong with the phone (or whether I need to reload the software).

If you're using a custom ROM, all bets are off. Try things with the stock ROM.

I don't think I'm using custom ROM. I'm assuming I would have had to explicitly choose to do so.

But, the t-mobile folks told me that they wanted to wipe all the data off the device and start over. Pain as I have lots of apps loaded, etc., but that was what I meant by reloading the software.