New Airtel 3G hacking from 2G plan

hai guys
it's a new trick


If you have a 3g activated airtel sim with a 3g supported phone you must use 3G speed in 2G plan.

1- You buy a Rs.15 2G Internet card
2- There have two 16 digit numbers in your card( scratch number & serial number)
3-dial *121*3*{serial number}#
4-then you get a short sms replay pin number
5-that time you write scrached nunmber and sent
5-now activate 3G speed in 2G plan
6-Enjoy 3G
         thanks