Home PLMN Roaming Control via Interworking Function
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current technologies lack effective mechanisms for the home network to control a user equipment's access to a visited network when connected via non-trusted access, leading to unfeasible options for preventing access or influencing access decisions.
Innovation Solution
The home public land mobile network decides whether to hand over control of a user equipment to a non-home network and communicates this decision, using rejection messages with specific causes to manage access, ensuring the user equipment only accesses the visited network when non-3GPP access is dropped.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the home network allows the UE to access the visited network, then the UE can maintain connectivity when non-3GPP access is unavailable, but the home network loses control over the UE's access decisions
Solution Approach 1:
The home network pre-configures the UE with a list of forbidden PLMNs and roaming restrictions before the UE attempts to access the visited network. This preliminary action prevents the UE from autonomously accessing visited networks, maintaining home network control while allowing flexible access when conditions permit.
Solution Approach 2:
The home network continuously monitors the UE's connection status and dynamically updates the forbidden PLMN list based on current non-3GPP access availability. When non-3GPP access is available, the home network can add visited networks to the forbidden list; when unavailable, it removes them, providing real-time feedback control.
2Device complexity
If the home network prohibits the UE from accessing the visited network, then the home network maintains full control, but the UE cannot access the visited network even when needed
Solution Approach 1:
The forbidden PLMN list is dynamically updated based on the UE's current connection status. The home network adjusts the list in real-time: adding visited networks when non-3GPP access is available, and removing them when non-3GPP access is unavailable, enabling adaptive control rather than static prohibition.
Solution Approach 2:
The UE autonomously enforces the forbidden PLMN list provided by the home network, automatically preventing access to visited networks without requiring continuous home network intervention. This self-service mechanism simplifies control management while maintaining access flexibility through dynamic list updates.
3Speed
If the UE autonomously decides to access the visited network, then access decisions are made quickly, but the home network cannot enforce access policies
Solution Approach 1:
The home network provides the UE with a pre-configured forbidden PLMN list and access policies before the UE needs to make access decisions. This allows the UE to quickly determine whether access is permitted without real-time communication with the home network, while still enforcing home network policies through the pre-provided restrictions.
Solution Approach 2:
The forbidden PLMN list acts as an intermediary mechanism that translates home network policies into actionable restrictions for the UE. The UE uses this list to make rapid access decisions autonomously, while the list itself ensures home network policy enforcement, bridging the gap between fast local decision-making and reliable policy control.
Data Source
AI summary
The invention provides a method performed by a home public land mobile network, PLMN, of controlling access of a user equipment, UE, device to a non-home PLMN when the UE device has an access to a non-trusted network and thereby a connection with the home PLMN via an interworking function entity, the method comprising in the event of the UE device requesting an attachment to the non-home PLMN, making in the home PLMN a decision as to whether control of the UE device should be handed over to the non-home PLMN; and communicating the decision to the non-home PLMN.