||Mobile number portability (MNP) enables mobile telephone users to retain their mobile telephone numbers when changing from one mobile network operator to another.
This is implemented in many ways in the different parts of the world.
In this standard, a customer wishing to port his/her number to contact the new provider (Recipient) who will then arrange necessary process with the old provider (Donor).
In this method, a customer wishing to port his/her number must first contact the existing provider, and get a Porting Authorisation Code (PAC) which the customer must then provide to the recipient. Recipient continues the port process by contacting the Donor once the recipient has the PAC.
The routing of calls or mobile messages (SMS, MMS) is the main issue on ce the mobile number has been ported. The best practice has been to use a a central database (CDB) of ported numbers. Then local copies of CDB is given to the network operators. From this CDB, they find out which network to send a call to. All Call Query (ACQ) is its alternative name and it is efficient and scalable.
Indirect RoutingIt is used in UK, and is inefficient and wasteful of the netwirk switching capacity. Here, the calls are still routed via the Donor network. The main disadvantage here is that if the Donor network develops a fault or goes out of business, the customers who have ported out of that network will lose incoming calls to their numbers.
Number Lookup Services
HLR query services may be used by the Service providers and carriers who route messages and voice calls to MNP-enabled countries for finding out the correct network of a mobile operator. Such services do the task of querying the operator's home location register (HLR) over the SS7 signalling network for finding out the current network of a mobile number.
The good news is that MNP is expected to be launched in India on 31 October 2010. Syniverese and Telecordia have already installed database servers for this.
Fro more details, see: