Non-3GPP Access Node Selection via Dual DNS Queries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing 'Combined N3IWF/ePDG selection' procedure in 3GPP Technical Specification 23.501 v17.3.0 is unclear regarding DNS operations when both N3IWF and ePDG are available to a mobile device, and it does not specify which FQDN to use for DNS requests.
Innovation Solution
A user apparatus sends two DNS requests, one using a first visited country FQDN associated with N3IWF and the other using a second visited country FQDN associated with ePDG, to determine the available PLMN identities for each type of non-3GPP access node, and then selects a non-3GPP access node based on the received DNS responses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a single DNS request is sent without specifying which FQDN to use, then the DNS operation is simplified, but the access node selection becomes unclear and unreliable
Solution Approach 1:
The patent segments the DNS operation into two separate DNS requests: one for N3IWF selection and one for ePDG selection. Each request uses a specific FQDN tailored to the access node type, ensuring clear and reliable selection while maintaining operational simplicity through structured separation of concerns.
2Reliability
If two separate DNS requests are sent for N3IWF and ePDG selection, then the access node selection becomes clear and reliable, but the DNS operation complexity increases
Solution Approach 1:
The patent implements a universal DNS query mechanism that handles both N3IWF and ePDG selection through a standardized two-request process. The user equipment applies the same DNS operation pattern for both access node types, using type-specific FQDNs, which reduces operational complexity despite performing two queries by maintaining consistency in the selection procedure.
3Ease of manufacture
If the FQDN is not specified for DNS requests, then the DNS request format is simplified, but the DNS response cannot be properly processed for access node selection
Solution Approach 1:
The patent applies local quality by using different FQDNs for different access node types (N3IWF and ePDG). Each FQDN is specifically tailored to the local requirements of the access node type being selected, ensuring that the DNS response contains the appropriate PLMN identity information for that specific access node type, thereby preventing information loss.
Data Source
AI summary
There is provided a user apparatus comprising a transceiver arranged to communicate with a non-3GPP access network; and a processor arranged to: determine that a non-3GPP access node is to be selected for providing a first service over the non-3GPP access network; send a first DNS request, via the transceiver, the first DNS request using a first visited country FQDN associated with a first type of non-3GPP access node; receive a first DNS response, via the transceiver, the first DNS response containing a first list of PLMN identities; send a second DNS request, via the transceiver, the second DNS request using a second visited country FQDN associated with a second type of non-3GPP access node; receive a second DNS response, via the transceiver, the second DNS response containing a second list of PLMN identities; select a non-3GPP access node based upon the received first and second DNS responses.