What is MNP or Mobile Number Portability?
MNP is a feature or service to a mobile subscriber, by which a mobile subscriber can change a serving mobile operator, without changing mobile number or MSISDN. The full form of MNP is mobile number portability. Before MNP, if a subscriber wants to use the services of another mobile operator then he has to purchase a new sim card with the new mobile number. Most of the people carry a mobile number which is very old or has been updated at multiple places e.g banks, on web sites, etc. This makes changing the mobile number to a difficult task. But at the same time, everyone wants to use better services from any of the mobile operators in that area.
With mobile number portability, the pain of changing a mobile number is gone. Now you can keep the same number but can change the mobile operator to enjoy better services. Full form mentions, portability. So changing a mobile operator is called porting mobile number from one service provider to another.
MNP and National Roaming:
There are countries like India, where roaming is applicable to a mobile number if it changes a significant location within a country. E.g if someone is living in Delhi and his employment location changes to Pune. Earlier to MNP, if a person wants to keep the same number, he has to but at least a roaming pack to reduce the phone bills. With MNP, a mobile number can be changed from one location to another within a country. So that national roaming charges can be removed.
Subscriber Profile Migration:
A subscriber profile is configured in the HLR. HLR is a database along with a software application. It keeps the subscriber record. When a new sim card is purchased. The HLR is updated for a new sim card with a new IMSI. After MNP the IMSI changes of a subscriber. The new IMSI belongs to the new mobile operator. The HLR of the new operator configured with its own new IMSI with the older MSDN. All services after MNP are control from the new HLR.
For porting a number to another mobile operator, there is an MNP process. The MNO process involves, deactivating and removing a subscriber from the current service provider and to configure and activate from the new service provider. Before moving to the new one, the bills from an existing service provider should be cleared.
Read the porting requirements carefully for the new mobile operator.
If the applicant is eligible, the signed copy of the documents is required by the mobile operator.
The new mobile operator issues the sim card to the subscriber.
Old sim card gets deactivated and new sim cards get activated.
For more details in India, you can visit the TRAI website.
Routing in the mobile network after MNP:
Before MNP, from a mobile number or MSISDN, the serving operator can be identified. From country code and from network code present in MSISDN, a call or SMS can be sent to the serving mobile network operator. For example, if a Vodafone subscriber dials an Airtel New Delhi India subscriber. Based on country code, the message for a call first reaches to India, then based on network code call reaches to the Airtel Delhi GMSC.
After the MNP, a mobile number and network operator don’t have any correlation. This leads to maintaining an MNP database. When a call or SMS originates, it queries to MNP database. Then routes to the serving operator. For example, if a subscriber is called, which is now an Airtel subscriber after MNP, before MNP, it was a Vodafone subscriber. Call first reaches the Vodafone, then an MNP database lookup is performed and the call is routed to the Airtel.