HPLMN, or Home Public Land Mobile Network, plays a crucial role in LTE (Long-Term Evolution) networks as it represents the home network of a mobile subscriber. It is a fundamental concept in the context of international mobile communication, defining the network to which a subscriber is affiliated and from which the subscriber receives primary services. This detailed explanation will delve into the significance, functions, and implications of HPLMN in LTE networks.
1. Definition of HPLMN:
- Home Public Land Mobile Network (HPLMN): HPLMN refers to the home network to which a mobile subscriber is associated. It is the network where the subscriber’s account is registered, and it is the network that provides primary mobile services to the subscriber.
2. Affiliation and Roaming:
- Subscriber Affiliation: When a mobile subscriber is within the coverage area of their home network, they are said to be in their HPLMN. The subscriber’s device registers with the home network, and services are provided as per the subscription plan.
- Roaming Outside HPLMN: When a subscriber travels outside the coverage area of their home network, they enter a visited network. In this scenario, the subscriber roams in the visited network, and the services are extended through inter-operator agreements.
3. Functions of HPLMN in LTE:
- Service Provisioning: The primary function of HPLMN is to provide mobile services to the subscriber based on their subscription plan. This includes voice, data, and other value-added services.
- Authentication and Authorization: HPLMN is responsible for authenticating and authorizing the subscriber, ensuring secure access to the network and services.
- Subscriber Identity Management: The subscriber’s identity and profile, including subscription details and service preferences, are managed within the HPLMN.
4. HPLMN in LTE Roaming:
- Interconnection Agreements: HPLMN establishes interconnection agreements with other networks to enable roaming services for its subscribers.
- Visited Networks: When a subscriber roams outside the HPLMN, the visited network provides services to the subscriber. The HPLMN and visited network coordinate to ensure a seamless and secure roaming experience.
5. Location Update and Handovers:
- Location Update: When a subscriber moves to a new location, the HPLMN is informed through location update procedures. This ensures that the subscriber’s location information is up-to-date.
- Handovers: In scenarios where a subscriber moves between different cells or eNodeBs (Evolved NodeB) within the LTE network, handover procedures are coordinated by the HPLMN to maintain the continuity of services.
6. Security Considerations:
- Subscriber Privacy: HPLMN is responsible for safeguarding the privacy and security of subscriber information and communication. Authentication and encryption mechanisms are employed to protect the integrity of the network.
7. Billing and Charging:
- Billing by HPLMN: The HPLMN is typically responsible for billing the subscriber for the services used. This includes call charges, data usage, and any other applicable fees.
- Charging Agreements: HPLMN may have charging agreements with visited networks to settle financial transactions related to roaming services.
8. Subscriber Management:
- Service Configuration: HPLMN manages the configuration of services for the subscriber based on their subscription plan and preferences.
- Subscription Updates: Any changes to the subscriber’s account, such as plan upgrades or additional services, are managed by the HPLMN.
9. International Standards and Roaming:
- ITU and GSMA Standards: International Telecommunication Union (ITU) and GSMA (Global System for Mobile Communications Association) standards guide the interoperability and roaming agreements between HPLMNs and visited networks.
10. Evolutionary Trends:
- Integration with 5G: The principles of HPLMN remain relevant as networks evolve to 5G. The integration with 5G networks involves new capabilities and enhancements, ensuring continuity of subscriber services.
Conclusion:
Home Public Land Mobile Network (HPLMN) in LTE is the home network to which a mobile subscriber is affiliated. It plays a central role in providing services, managing subscriber identities, ensuring security, and facilitating roaming capabilities. HPLMN is a foundational concept that continues to be integral in the evolving landscape of mobile communication.