AMF UE State Mismatch Handling in 5G RAN
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Solution Overview
Problem
In 5G networks, the RRC inactive state mismatch between UE and network leads to air interface resource waste and packet loss due to ineffective paging procedures, causing increased overhead and resource inefficiency when UE moves out of the RAN paging area.
Innovation Solution
The AMF processes status mismatches by receiving NAS messages or N2 interface messages to determine the UE's connected state and notify the old RAN node to release the UE context and user plane connections, ensuring seamless transition to a new RAN node that supports the RRC inactive state, thereby reducing paging overhead and packet loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the old RAN anchor node continues to page the UE after the UE moves out of the RAN Paging area, then the core network maintains transparency and the RAN node can receive downlink signaling, but the paging overhead increases and air interface resources are wasted
Solution Approach 1:
The patent implements a feedback mechanism where the new RAN node detects UE presence and sends notification to the old RAN anchor node. This feedback loop allows the old node to stop paging when the UE has moved, resolving the contradiction between maintaining core network transparency and avoiding resource waste.
Solution Approach 2:
The patent introduces an intermediary notification mechanism between RAN nodes. The new RAN node acts as an intermediary that informs the old RAN anchor node about UE location changes, enabling the system to maintain transparency while preventing unnecessary paging operations.
2Reliability
If the old RAN anchor node repeats RAN level paging multiple times, then it attempts to reach the UE, but packet loss increases and resources are consumed without success
Solution Approach 1:
The patent applies preliminary action by having the new RAN node proactively notify the old RAN anchor node before the old node performs repeated unsuccessful paging. This advance notification prevents the old node from wasting resources on futile paging attempts, thereby reducing packet loss.
3Stability of the object's composition
If the UE remains in RRC inactive state with the old RAN anchor node, then the connection is maintained, but the UE cannot receive paging when moving to a new RAN node coverage
Solution Approach 1:
The patent implements dynamics by allowing the RRC connection to be maintained with the old RAN anchor node for stability while enabling the UE to be paged by the new RAN node for mobility adaptability. The system dynamically manages the paging process across different RAN nodes without requiring UE state changes.
Data Source
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AI summary
Disclosed are a method and device for processing non-matching between a UE unit and a network state applicable to an access and mobility management (AMF) function. The method comprises: upon receiving a non-access stratum message transmitted by a UE unit or an N2 interface message transmitted by a radio access network (RAN) node, determining that the UE unit is in a connected state at a network side; and if it is determined that a change occurs in a RAN node serving the UE unit, notifying said RAN node that a context of the UE unit and an existing user plane connection are to be released. The invention solves technical problems in the prior art of inefficient use of an air interface resource and packet loss, thereby reducing paging overheads and packet loss.