- Mumbai/Bombay: For some reason, near the airport service (Sheraton) was pretty shaky. I would occcassionaly catch a signal and get some data briefly. The closer you go to the center of the city, the better and more reliable service was for both data and voice.
- Pune/Poona: This was the worst location for service. Overall, service was sketchy and unpredictable -- bad enough to make me wonder if my account had been frozen or put on hold. Basically you can go up to 8 hours with no service and then come up for 3-4 hours in the same location. Relatively frustrating, but just seems to be the state of the telecommunications in the city.
- New Delhi/Noida: Flawless. Service was excellent from the time we stepped off the plane and covered us without issue all the way out to the suburb of Noida. The quality was as good as if you were in the United States.
- Frankfurt, Germany: While on layover, the phone worked just as it did in Noida. No issues to report and service was accessible from the second I landed.
Hopefully this will help you plan the telecommunications for your trip to India. The bottom line is that if you are going to Pune/Poona and you are on Cingular -- you may want to look at the various partnerships and see if you can rent a phone while there or bring one from a different US provider that would provide better service.