Recipient Network (Mobile Number Portability)

Description

The Recipient Network is a concept defined in the context of Mobile Number Portability (MNP), specified in 3GPP TS 21.905 (Vocabulary) and TS 22.066 (Support of Mobile Number Portability). It denotes the network that receives a mobile number in the porting process — that is, the network to which a subscriber is moving their number from their current (donor) network. When the porting process is complete, the Recipient Network becomes the subscription network for that number, meaning it is now the home network responsible for the subscriber's service provisioning, subscription management, and call/session routing.

Mobile Number Portability allows a subscriber to retain their existing mobile number when changing from one mobile network operator to another. This is a regulatory requirement in many countries and is intended to promote competition by removing the switching cost associated with changing numbers. The porting process involves coordination between the donor network (the original operator), the recipient network (the new operator), and often a centralized number portability database or clearinghouse. The Recipient Network initiates or accepts the port request, provisions the subscriber in its systems, and updates routing information so that incoming calls and messages are directed to the correct network.

From a technical standpoint, the Recipient Network must handle several functions. It must allocate the ported number within its own numbering plan and ensure that its Home Location Register (HLR) or Home Subscriber Server (HSS) contains the correct subscription data. It must also coordinate with the donor network to deactivate the number there and with the number portability database to update the routing entry. Once the port is complete, the Recipient Network is responsible for all aspects of service delivery, including mobility management, call control, and supplementary services.

The concept is closely tied to the distinction between the 'subscription network' and the 'donor network.' The subscription network is the network with which the subscriber currently has a subscription; before porting, this is the donor network, and after porting, it is the Recipient Network. This distinction is important for routing and for determining which network is responsible for the subscriber at any given time. The Recipient Network's role is thus both operational and regulatory, ensuring that number portability works transparently to the end user.

Because MNP is a mature feature, the definition of 'Recipient Network' has remained essentially unchanged from Rel-4 through Rel-19. Its stability reflects the fact that the fundamental process of number porting — moving a number from one network to another — has not changed, even as underlying network technologies have evolved from GSM/UMTS to LTE and 5G. The term remains a foundational concept in numbering, addressing, and mobility management standards.

Purpose & Motivation

The concept of the Recipient Network exists to support Mobile Number Portability, a regulatory and competitive requirement that allows subscribers to keep their mobile number when changing operators. Without a clear definition of the recipient network, the porting process would lack a standardized way to identify the network that is taking over the number and the responsibilities that come with it. The Recipient Network provides that anchor: it is the entity that receives the number, provisions the subscriber, and ultimately becomes the subscription network.

Before MNP was standardized, changing operators typically meant changing numbers, which created a significant barrier to competition and inconvenienced users. The introduction of MNP in 3GPP specifications, starting around Rel-4, addressed this by defining the roles of donor network, recipient network, and subscription network, along with the procedures for porting. The Recipient Network is central to this framework because it is the destination of the port and the network that must ensure continuity of service.

The term also helps clarify routing and service responsibilities. By distinguishing the recipient network from the donor network and the subscription network, the standards enable precise handling of calls, messages, and subscription data during and after the porting process. This is essential for interoperability between operators and for ensuring that end users experience no disruption when they port their numbers. The definition has remained stable across releases, underscoring its enduring relevance.