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Mobile number portability (MNP) enables mobile telephone users to retain their mobile telephone numbers when changing from one mobile network operator to another.

[edit] General overview

MNP is implemented in different ways across the globe. The international and European standard is for 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). This is also known as 'Recipient-Led' porting. The UK is the only country to not implement a Recipient-Led system, where a customer wishing to port his/her number is required to contact the Donor to obtain a Porting Authorisation Code (PAC) which he/she then has to give to the Recipient. Once having received the PAC the Recipient continues the port process by contacting the Donor. This form of porting is also known as 'Donor-Led' and has been criticised by some industry analysts as being inefficient. It has also been observed that it may act as a customer deterrent as well as allowing the Donor an opportunity of 'winning-back' the customer. This might lead to distortion of competition, especially in the markets with new entrants that are yet to achieve scalability of operation.

[edit] Technical details

A significant technical aspect of MNP is related to the routing of calls or mobile messages (SMS, MMS) to a number once it has been ported. There are various flavours of call routing implementation across the globe but the international and European best practice is via the use of a central database (CDB) of ported numbers. Network operators generally hold local copies of CDB and query it to find out which network to send a call to. This is also known as All Call Query (ACQ) and is highly efficient and scalable. Majority of the established and upcoming MNP systems across the world are based on this ACQ/CDB method of call routing. One of the very few countries to not use ACQ/CDB is the UK where calls to a number once it has been ported are still routed via the Donor network. This is also known as 'Indirect Routing' and is highly inefficient as it is wasteful of transmission and switching capacity. Because of its Donor dependent nature, Indirect Routing also means 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. The UK telecoms regulator Ofcom completed its extended review of the UK MNP process on 29 November 2007 and mandated that ACQ/CDB be implemented for mobile to mobile ported calls by no later than 1 September 2009, and for all other (fixed and mobile) ported calls by no later than 31 December 2012.

Prior to March 2008 it took a minimum of 5 working days to port a number in the UK compared to 2 hours only in USA, as low as 20 minutes in the Republic of Ireland, 3 minutes in Australia and even a matter of seconds in New Zealand. On 17 July 2007, Ofcom released its conclusions from the review of UK MNP and mandated reduction of porting time to 2 working days with effect from 1 April 2008. On 29 November 2007, Ofcom completed its consultation on further reduction to porting time to 2 hours along with recipient led porting and mandated that near-instant (no more than 2 hours) recipient led porting be implemented by no later than 1 September 2009.

[edit] Mobile number portability in the Internet telephony / VOIP environment

Mobile Number Portability also impacts the internet telephony, or VOIP (Voice over IP) business. A voice call originated in the VOIP environment which is routed to a mobile phone number of a traditional mobile carrier also face challenges to reach its destination in case the mobile phone number is ported.

VOIP is clearly identified as a Least Cost Routing (LCR) voice routing system, which is based on checking the destination of each telephone call as it is made, and then sending the call via the network that will cost the customer the least. With GSM number portability now in place, LCR providers can no longer rely on using the network root prefix to determine how to route a call. Instead, they now need to know the actual current network of every number before routing the call.

Therefore, VOIP solutions also need to handle MNP when routing a voice call. In countries without a central database like UK it might be necessary to query the GSM network about the home network a mobile phone number belongs to. As VOIP starts to take off in the enterprise markets because of least cost routing options, it needs to provide a certain level of reliability when handling calls.

MNP checks are important to assure that this quality of service is met; by handling MNP lookups before routing a call and assuring that the voice call will actually work, VOIP companies give businesses the necessary reliability they look for in an internet telephony provider. Some messaging operators provide a Voice/Network Query service, which helps not only traditional voice carriers but also VOIP providers to query the GSM network (HLR Lookup) to find out the home network of a ported number.

In countries such as Singapore, the most recent Mobile Number Portability solution is expected to open the doors to new business opportunities for non-traditional telecommunication service providers like wireless broadband providers and voice over IP (VOIP) providers.

Last but not least, in November 2008 the North American FCC (Federal Communications Commission) released an order extending number portability obligations to interconnected VOIP providers and carriers that support VOIP providers.

[edit] Number Lookup Services

Service providers and carriers who route messages and voice calls to MNP-enabled countries might use HLR query services to find out the correct network of a mobile phone number. A number of such services exist, which query the operator's home location register (HLR) over the SS7 signalling network in order to determine the current network of a specified mobile phone number prior to attempted routing of messaging or voice traffic.

[edit] Mobile number portability by country

[edit] Americas

[edit] Asia Pacific

[edit] Europe

[edit] Middle East and Africa

[edit] References

• Daniel AJ Sokolov, Problems with VOIP and Convergent Services [1]
• VOIP News, US Number Portability Extends to VOIP Providers [2]
• IDA Singapore, Singapore to Enjoy Full Mobile Number Portability from 13 June [3]

[edit] See also

• Local number portability

[edit] External Links

• FAQs on Mobile Number Portability in India
• Telcordia Joint Venture - Mobile Number Portability Clearing-House
• Ofcom Mobile Number Portability review of the porting process