What's your phone brand and model?
If you want to switch over to other Network then you need to get it unlocked your phone.You can unlock your phone using unlock code. You can get the unlock code for your phone from your Network service provider or any third party online vendors like http://www.onlinegsmunlock.com/supported-phones/rs16wp7/ here you need to specify your phone model, country, IMEI number of your phone. Then they deliver unlock code to you through mail with unlocking instructions.
sahana, September 2013
