Never Discard your Number when you change places or Networks

If you have read the Title properly and wondering if it’s true. Well hell YEA!!! soon in india we can retain the same number even if we change places or move to other networks. Cool isn’t it?
No more burden of letting your friends know of your new number? no more missing out calls from people whom you failed to communicate of a number change.
The number portability for mobile services will be introduced by the end of the fourth Quarter in India. This means if you are unhappy with your mobile service provider but have been unable to shift to another because it would mean changing your number, you will be able to switch while retaining the same number.
Full number portability allows users to retain their telephone numbers not just when they change service providers. They can also retain the number when they are switching service types — say, from mobile to fixed line — or when changing locations — say, from Delhi to Mumbai or vice versa. The portability envisaged by Raja (telecom Minister), however, will only allow wireless number portability.
This will be first Introduced in Indias Four metros and the rest of the India in Phases. This would be a great feature for People on the move.
Some doubts that arises
• I used a number in Kerala and moved over to karnataka and i retained the same number. When people from Karnataka calls me up? will they be charged for a STD call?? and vice versa?
• What would be my roaming rates in this case? Will it shoot up?
• How long will it take for the Transformation to take place. Like i moved to a new place and decided to change to local network. In how many days will i get my old number moved to a local mobile service provider?