Telecom Regulatory Authority Of India - Subsection
Section 2(g) in The Telecommunication Mobile Number Portability Per Port Transaction Charge and Dipping Charge Regulations, 2009
(g)"Mobile Number Portability" means the facility which allows a subscriber to retain his mobile telephone number when he moves from one Access Provider to another irrespective of the mobile technology or from one cellular mobile technology to another of the same Access Provider;
