Visited Public Mobile Network

In the intricate realm of mobile telecommunications, understanding the role of Visited Public Mobile Network (VPMN) is crucial. Let's delve into the essence of VPMN, its functionalities, and its significance in the realm of roaming scenarios.

What is VPMN?

VPMN, short for Visited Public Mobile Network, represents the network utilized by a mobile subscriber while roaming outside their Home Public Mobile Network (HPMN). But what does this entail?

VPMN Definition: VPMN is an integral part of roaming scenarios, providing mobile subscribers with access to services contracted with their HPMN while they are outside its coverage area.
VPMN Group: Within the context of roaming agreements, VPMNs are often categorized into groups based on geographical coverage and service offerings.

Navigating Roaming Scenarios

Understanding how VPMN operates in roaming scenarios sheds light on its significance:

Subscriber Authentication: Before granting access to visiting users, the VPMN queries the HPMN to verify the services to which the users are subscribed, ensuring seamless service continuity.
Roaming Agreement: To enable subscribers to access roaming facilities in a VPMN, telecom operators must negotiate roaming agreements, ensuring mutual cooperation and service provision.

VPMN in Action

Let's explore the operational dynamics of VPMN:

Geographical Coverage: VPMNs provide geographical coverage to roaming subscribers through mobile switching centers (MSCs) and visited location registers (VLRs), enabling seamless connectivity.
Service Provisioning: Once authenticated, subscribers gain access to the services contracted with their HPMN, ensuring uninterrupted service delivery while roaming.

Summary

The Visited Public Mobile Network (VPMN) is the network used by a mobile subscriber while roaming outside of their Home Public Mobile Network (HPMN) which is a network from the operator by which a mobile subscriber has a subscription to handle the user’s subscription and services. The VPNM is one of the three major actors that intervene in roaming scenarios. VPMN geographical coverage area enables users gain access to the services contracted with the HPMN.

Before providing access to the visiting users (through the mobile switching center/visited location register [MSC/VLR], which provides geographical coverage to requesting subscribers), the VPMN queries the HPMN about the services to which these users are subscribed (information held in the home location register [HLR] database owned by the HPMN). Then, if the subscriptions are correct, the subscribers will be enabled to gain access to the corresponding services.

To enable the operator’s subscriber to engage roaming facilities in a given VPMN, a roaming agreement must previously be negotiated between the two telecommunications operators. The procedures for drafting this business aspect are usually standardized, as in the case of Global System for Mobile Communications (GSM) service through the GSM Association procedures.