Change Your current sim as 4g SIM (simple method)

go here

http://www.airtel.in/4g/sim-
swap.html

*SMS SIM <20 digit SIM number>
from your existing airtel
connection to 121

*The 20 digit SIM number is
available at the back of your new
SIM card

*Reply with 1 to confirm your
request

*Wait for the phone to get
disconnected from the network
Then change the SIM and switch it
on to get connected again.

*Your new 4G airtel SIM will be
active within 5 minutes


*No need to change your mobile
number

*You can also upgrade to an airtel
4G SIM at the nearest store...


thankxx ....n enjoy ;)