AMF Emergency Registration Handling for Disaster Roaming Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In disaster roaming scenarios, user equipment (UE) remains registered for disaster roaming services even after the disaster condition has ended, leading to unnecessary service provision and inefficient signaling due to incorrect application of EPS-related security algorithms.
Innovation Solution
The access and mobility management function (AMF) informs the UE that it is registered for emergency services only, maintains the PDU session for emergency services, and sets a timer for returning to the original network, while ensuring the UE does not receive unnecessary EPS-related security algorithms during disaster roaming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE remains registered for disaster roaming services after the disaster condition has ended, then the UE can continue to access the network, but unnecessary service provision and inefficient signaling occur due to incorrect application of EPS-related security algorithms
Solution Approach 1:
The AMF proactively informs the UE about the end of disaster condition before the UE attempts to use EPS security algorithms, preventing unnecessary signaling exchanges. The network sends a registration accept message with an indication that disaster roaming service is no longer available, allowing the UE to update its state and avoid incorrect security algorithm application.
Solution Approach 2:
The AMF provides feedback to the UE regarding the status of disaster roaming service availability. By sending registration accept messages with appropriate indicators, the network communicates service status changes to the UE, enabling the UE to adjust its behavior and avoid using EPS security algorithms when they are not applicable.
2Ease of operation
If the AMF provides EPS-related security algorithms to the UE during disaster roaming, then the UE can establish security contexts, but unnecessary service provision occurs when the UE is only registered for emergency services
Solution Approach 1:
The AMF applies different quality of service treatment based on the UE's registration type. For UEs registered only for emergency services during disaster roaming, the network provides limited service without establishing full EPS security contexts. The AMF checks the registration type and selectively provides or withholds EPS security algorithms based on whether the UE is registered for emergency services only or for full disaster roaming services.
Solution Approach 2:
The network changes the service parameters provided to the UE based on the disaster condition status and registration type. When the UE is registered for emergency services only, the AMF modifies the security context parameters by not providing EPS security algorithms, thereby adapting the service level to match the actual needs and avoiding unnecessary resource consumption.
3Productivity
If the UE is automatically redirected to the original network after disaster ends, then service optimization is achieved, but service interruption occurs for UEs with active emergency PDU sessions
Solution Approach 1:
The network dynamically adjusts the UE's service status based on the presence of active emergency PDU sessions. When the AMF detects that a UE has an active emergency PDU session, it modifies the redirection behavior by setting the 5GS registration type to indicate emergency services only, thereby preventing automatic network release and ensuring continuous service availability for emergency communications.
Solution Approach 2:
The AMF proactively identifies UEs with active emergency PDU sessions before redirecting them to the original network. By checking the PDU session status in advance and adjusting the registration type accordingly, the network prevents service interruption for emergency communications while still optimizing service for UEs without active emergency sessions.
Data Source
AI summary
The disclosure relates to a 5th generation (5G) or 6th generation (6G) communication system for supporting a higher data transmission rate. A method performed by an access and mobility management function (AMF) in a public land mobile network (PLMN) providing disaster roaming service is provided. The method includes determining whether a disaster condition has ended in a previous PLMN associated with a user equipment (UE) which is registered for the disaster roaming service, in response to determining that the disaster condition has ended and the UE has an emergency protocol data unit (PDU) session, generating a message indicating that the UE is registered for emergency service, and transmitting, to the UE, the message.