Non-3GPP AN Selection Using Requested NSSAI Rejection Feedback
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Solution Overview
Problem
In certain situations, terminal registration requests are repeatedly rejected, posing a challenge in 3GPP LTE and NR systems.
Innovation Solution
The terminal performs a registration request using a message containing the same Requested NSSAI as the previous registration request.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the terminal sends repeated registration requests with different Requested NSSAI information, then the terminal attempts to resolve registration failures, but this leads to repeated registration rejections and increased signaling overhead
Solution Approach 1:
The terminal performs preliminary analysis of the registration rejection cause before sending the next registration request. By examining the rejection reason and maintaining the same Requested NSSAI when appropriate, the terminal avoids unnecessary retransmissions and focuses on resolving the actual registration failure, thereby reducing registration establishment time while improving success rate.
Solution Approach 2:
The terminal uses feedback from registration rejection messages to adjust its registration strategy. By analyzing the rejection cause and determining whether to maintain or change the Requested NSSAI, the terminal creates a closed-loop control mechanism that improves registration success while minimizing unnecessary signaling overhead and time consumption.
2Adaptability or versatility
If the terminal changes Requested NSSAI information in repeated registration requests, then the terminal attempts to adapt to network conditions, but this may cause inconsistent registration behavior and increased network processing load
Solution Approach 1:
The terminal applies different strategies for Requested NSSAI management based on the specific registration rejection cause. When the rejection is due to network slice availability issues, the terminal maintains the same Requested NSSAI. When rejection is due to other causes, the terminal may adjust the Requested NSSAI. This localized, cause-specific approach improves registration adaptability while keeping management complexity可控.
Solution Approach 2:
The terminal dynamically adjusts the Requested NSSAI based on real-time registration rejection analysis. The decision to maintain or change Requested NSSAI is not static but adapts to the specific rejection cause received from the network, enabling flexible registration behavior that balances adaptability with manageable complexity.
Data Source
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AI summary
Provided in one embodiment of the present disclosure is a method by which a NAS layer of a UE performs communication. The method comprises the steps of: transmitting a first registration request message to a specific non-3GPP access network (AN) node through a non-3GPP access, the first registration request message including Requested NSSAI; receiving a registration reject message from an AMF on the basis that the specific non-3GPP AN node does not support the Requested NSSAI, the registration reject message including target non-3GPP AN node information; and transmitting a second registration request message, the second registration request message including the Requested NSSAI on the basis of the performance of the step of using the target non-3GPP AN node information so as to transmit the second registration request message.