Theory on Mobile Number Portability (MNP), sample implementation and issues related to introduction in India.

April,13 – 2008

In Indian cellular communication scenario, the term MNP is becoming more popular. Sticking to Herbert Spencer’s theory on “Survival of the fittest”, the mobile operators will be forced to follow this theory in serving the customers. Either they have to satisfy their customers with the service or lose them to their competitors without any problem to the customers. It could also be termed as, a customer having the option of switching service providers without changing the mobile number.

With current scenario, if a customer is dissatisfied on the service by mobile operator either he has to reluctantly accept the service or switch to another service provider that he wishes. In the later case, he has to drop his identity, the mobile number. In most cases when the mobile number is used for all business and family correspondence, it becomes generally impossible to leave the number. To overcome these hardships, the concept of MNP (Mobile Number Portability) was introduced.

History:The first implementation of MNP starts in late 1990s with Singapore

implementing the MNP (limited) functionality in 1997 followed by Hong Kong in 1999, Spain in 2000, Australia in 2001 and list continues to grow.

Basic glossary and terms used in MNP:

Ported out – If a subscriber moves to new service provider, for the old service provider, he is a “ported out” subscriber.

Ported in - If a subscriber moves to new service provider, for the new service provider, he is a “ported in” subscriber.

Donor – The service provider left by the subscriber is termed as “donor” Recipient – The service provider joined by the subscriber is termed as “recipient” CDB – Central DatabaseACQ – All Call Query

Concept and Implementation:

In terms of concept, the MNP functionality is used only in MT transactions of voice and messaging. For MO transactions, the current flow scenario remains unchanged. Only for the MT functionalities, the mobile number has to be identified and the corresponding service provider has to be interrogated for optimal routing of the service.

There are two basic implementation of MNP.

a) Indirect Routing or decentralized or bilateral architecture: This model works bilaterally between the donor and recipient service

providers who are responsible for informing all others of the change. It would suit to markets with less number of service providers. Each provider will have a dedicated setup and comprehensive database of ported out and ported in subscribers. As the number of service providers increases, the bilateral approach becomes a great burden to all service providers involved in terms of time, cost and resources. FNR (Flexible Number Register) will help the service providers have the ported database in addition to the original HLR database.

Sample implementation of MNP in middle east:In one of the countries of middle east, the MNP service is implemented in

bilateral architecture. There are two operators available in the country and each have their own customized system for handling the MNP database. Whenever a customer wants to change his service provider, he visits the recipient provider and initiates a request to port in the subscription with the recipient provider. The recipient party then coordinates with the donor party for porting the number. During the process, the donor deletes the number from its HLR database and updates the number in its FNR – ported out list. Similarly the recipient party updates the number in its HLR database and FNR – ported in list.

Coming to the MT transactions, there are two possible options,1. Call from same PLMN: As both the service providers have the complete list of Ported out and ported in numbers, the originating MSC will route the call either to its own network or to other network based on available database.2. Call from outside the PLMN: As the originating network need not to be aware of the MNP functionality, it will route the call based on the number series database available with it. The recipient network will make further analysis for routing of the call by following the procedures mentioned in previous point.

Ericsson MSC perspective of indirect routing – MNP:

For a single operator, three considerations have to be made.1. Analysis for ported in Home subscriber or Native subscriber. 2. Analysis for ported in other PLMN subscriber or non-Native subscriber.3. Analysis for ported out subscriber.

The value ‘D’ is represented as #13 in Ericsson AXE. Value ‘#’ is represented as #12

In sample network, for case 1, the reply from the FNR will have a format of mccD98msrn. It is represented in B-number analysis as 8-mcc#1398msrn.

For case 2, the format is also mccD98msrn.

For case 3, the call is routed to the other operator in mccD95msisdn format.

The main aim of using the special formats D95 and D98 is to help the network in discriminating the numbers for routing. These special indicators can be assigned upon the network convenience. The receiving network should recognize the numbers based on the format received.

Available origins supporting FNR:

Result from HLR in BO=8 with mcc#1395. Result from IN in BO=78 with mcc#1395 and mcc#1398. The Origin 8 is derived from EXROP:DETY=GRI; and the origin 78 is derived from SHRSP:OSR=ALL; . In this case, the 75 gets modified into 76 and in turn into 78.

Issues with this type of routing:

• Routing to the ported user is indirect and possibly costly, because additional transitcharges, interconnect charges, and/or extra conveyance costs may be generated evenwhen the originating provider is the same as the terminating recipient provider.• For the donor network, billing associated with ported and non-ported numbers cannot bedifferentiated easily.• If the donor network uses a small, non-high-performance database, increased call setuptime for ported numbers is inevitable.• Due to the dependence on the donor network, the receiving network cannot serve theported user reliably, because it has no control over the quality of service on the donornetwork.• If the donor provider discontinues its operations or is experiencing a network failure,the ported subscribers cannot be reached even if they ported numbers years ago. This isa growing concern due to the increasing number of failures and the high cost to put thesesubscribers back in service.

b). Direct Routing or centralized architecture:

In direct routing, the concept of CDB comes into picture. This central database or Central clearing house will handle all activities related to porting of subscribers between service providers. This model is suited for markets with several service providers and this model is currently used almost in all MNP implementations. Two options are available with this model with all the service providers updating the ported number database in synchronization with the CDB and the other is to query the CDB for all call interrogation to get proper routing procedure. After obtaining the rules, rest of the call is handled normally.

Thus the complexity and risk is reduced to a minimum with the little increase in work for the service providers to make an additional check. This model is highly recommended for MNP implementation and the routing procedures can be discussed between the operators.

MNP in India:

In India, this service is expected to be operational by the mid of 2009. The DoT (Department of Telecom) has issued license to two global companies to implement the feature in two zones. Telecordia, the world’s leading provider of MNP services has solutions deployed across none countries including the US, Canada, Egypt, Greece and South Africa has been issued with license for implementing MNP in north and west zone in India. Syniverse technologies, also a major player in voice and data solutions has been issued with license for south and east zones. The license issued in February 2009 quotes the companies to start service for metro cities by six months and other regions within twelve months. They will provide a “central clearing house” model for MNP in India.

Interesting facts about MNP:

1. United Kingdom is yet to switch to centralized solution ( as of Jan2008).2. The time taken to port a subscriber between the service providers should not be

greater than the time taken to activate a new subscriber.3. It takes only 3 minutes in Australia to port a subscriber successfully.4. The first MNP implementation was made in 1990 Singapore.5. Free of charge in countries and chargeable in some countries.

ITU-T standardizations - http://www.itu.int/rec/T-REC-E.164-199811-I!Sup2/en

Ramanathan Sundaram, xpotentialram@gmail.com