Phones, Operators and Frequency bands

When you are traveling internationally and trying to use the same phone everywhere (whether with the local sim or thru the roaming), it becomes difficult to keep track of what frequencies are used by what operators in which region of the country. Now with 3G (UMTS), the matrix is even more convoluted.

I’m listing the details before for my own convenience, but if you need additional information let me know.

GSM/GPRS/EDGE Bands (2G)

There are four different frequency bands which are used by the phone operators:

• 850 MHz 
• 900 MHz 
• 1800 MHz 
• 1900 MHz

US generally operates on 1900 MHz but AT&T still uses 850 MHz for some areas. T-Mobile uses only 1900 MHz but in some cases it provides roaming with AT&T using 850 MHz band. While internationally, you would need 900 MHz and 1800 MHz for GSM/GPRS.

 ATT GSM in US: 850 MHz and 1900 MHz (850 mainly for rural coverage)

 ATT 3G in US: 850/1900 MHz

 T-Mobile GSM in US: 1900 MHz
 T-Mobile 3G (UMTS/HSPA/HSPA+) in US: AWS 1700(uplink)/2100(downlink) MHz

 Roger Canada UMTS: 850 MHz
 Wind Mobile Canada: UMTS 1700

 Europe: O2/Vodafone/Orange : 2100 UMTS

Devices:

• iPhone : quadband GSM/GPRS/EDGE (850, 900, 1800, 1900). And HSDPA/UMTS : 850/1900/2100 
• TMobile US Nexus One: Quadband GSM/GPRS/EDGE. UMTS: 1900/1700/2100 
• TMobile US HTC HD2 : Quadband GSM/GPRS/EDGE. UMTS: 1900/1700/2100
• TMobile AT&T Nexus One: Quadband GSM/GPRS/EDGE. UMTS: 850/1900/2100

So, you cannot get an iPhone working on TMobile 3G and you cannot get a TMobile US Nexus One working on ATT 3G since its missing the 850 block. But there is an ATT friendly Nexus One too.
The 2100 UMTS is there to be friendly with Europe which operates on 1900/2100

India:
Hutch Delhi : 900/1800
Idea Delhi: 1800
Bharti Airtel Delhi: 900
MTNL Delhi: 900
Vodafone Delhi: 900/1800

Idea Haryana: 900
Hutch Haryana: 900

Hutch UP East/West: 900
Idea UP West: 900