Authentication Service Selection for SNPN Access Control

The patent applies preliminary action by pre-configuring routing indications and group identifiers in the terminal before it needs to access the SNPN. When the terminal receives a credential for accessing SNPN, the credential includes a routing indication that points to a specific authentication service network element. This pre-established routing information allows the terminal to directly select the appropriate authentication service without complex real-time decision-making, thus resolving the contradiction between gaining access capability and avoiding complexity in authentication service selection.

The patent introduces an intermediary mechanism through the use of a default credential server and routing indications. The default credential server acts as an intermediary that provides credentials with embedded routing information to terminals. This intermediary layer decouples the terminal from the complexity of authentication service selection by providing pre-packaged credentials that contain the necessary routing indications, thereby enabling access capability while simplifying the authentication service network element selection process.

The patent applies parameter changes by transforming the authentication service selection problem from a complex decision-making process into a simple parameter lookup. The routing indication serves as a key parameter that directly maps to the appropriate authentication service network element. By changing the selection criterion from evaluating multiple factors to simply following the routing indication parameter, the patent makes authentication service network element selection straightforward and measurable, thus resolving the contradiction between ease of network access and difficulty of authentication service selection.

The patent applies segmentation by dividing the authentication service selection process into distinct components: the terminal holds a routing indication, the credential includes authentication information, and the network element selection is determined by matching the routing indication to the appropriate authentication service. This segmentation separates the complex selection logic from the terminal and embeds it in the credential structure, making the overall process easier to operate while simplifying the detection and measurement of authentication service network element selection.