Mobile Number Portability

Mobile Number Portability
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Enables a subscriber of a telecommunication provider to port his/her service to another telecommunication provider
in that country, but retain his/her telephone number.

Mobile number portability (MNP) is the implementation in the GSM network of the NP concept.
MNP is introduced in GSM Release R98.

NP or MNP mean that a subscriber has a telephone number belonging to one operator
(number range holder network), while that subscriber is a subscriber of another operator (subscription network).

At least the following NP cases may be defined:

The terms ‘number range holder network’ and ‘subscription network’ are defined for MNP, but also apply
functionally to NP.

• number portability between two GSM networks;
• number portability between two PSTNs;
• number portability between GSM and PSTN.

NP between GSM and PSTN is less common than NP between homogeneous networks.
Denmark is one example of a European country that uses mobile-fixed NP.

One aspect of many telecommunications networks is that a subscriber is identified with a number,
whereby the number is part of a number range.

The number by means of which a subscriber is identified has various purposes, including:

• routing – when a call is established, the routing of that call through the network is based on the
number that is used to identify that subscriber, e.g. a call to +31 65 . . . is routed to the network
from KPN Mobile (‘65’) in The Netherlands (‘+31’).27

• network identification – the number indicates the network that a subscriber belongs to, e.g. a
subscriber with number +31 13 . . . is associated with a local exchange in a particular region of
the PSTN from KPN Netherlands.

• tariff – a subscriber from T-Mobile Netherlands may be charged a lower rate for calls to other
T-Mobile Netherlands subscribers than for calls to Orange Netherlands subscribers.
The introduction of NP affects the above associations of a telephone number.