PDU Session ID Allocation for Non-5GC NAS Terminals
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Solution Overview
Problem
In 5th generation (5G) communication systems, there is no specific method to create or allocate a unique Protocol Data Unit (PDU) Session ID for terminal devices not supporting 5GC NAS, leading to uncontrolled system behavior due to duplicated IDs when accessing networks from Evolved Packet Core/EPC or untrusted Wireless Local Area Networks (WLAN).
Innovation Solution
A network node selects a PDU session ID from a group not allocated to the terminal device, using an evolved packet system bearer identity (EPS Bearer ID) to ensure uniqueness, with specific mapping relationships and values, and retrieves used IDs from a data management node to avoid conflicts during N1 mode capability changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a PDU session ID is allocated for a terminal device not supporting 5GC NAS, then the terminal device can communicate with 5G core network nodes, but duplicated PDU session IDs may be generated leading to uncontrolled system behavior
Solution Approach 1:
The patent introduces a network node as an intermediary that manages PDU session ID allocation for terminal devices not supporting 5GC NAS. The network node receives the terminal device identifier, determines an appropriate PDU session ID, and allocates it through controlled procedures, preventing duplication and ensuring uniqueness while maintaining compatibility with legacy terminal devices
Solution Approach 2:
The patent implements a feedback mechanism where the network node tracks allocated PDU session IDs and uses this information to determine available IDs for subsequent allocations. This feedback loop ensures that duplicate IDs are not allocated and maintains system reliability across multiple terminal devices
2Adaptability or versatility
If the terminal device and PGW-C+SMF both generate PDU session IDs, then flexibility in ID allocation is improved, but conflicts and uncontrolled system behavior occur
Solution Approach 1:
The patent merges the PDU session ID generation functionality into the network node, consolidating the responsibility for ID allocation. Instead of having both the terminal device and PGW-C+SMF independently generate IDs, the network node centrally manages this process, simplifying the control mechanism while maintaining flexibility in ID assignment
3Ease of operation
If PDU session IDs are allocated without a specific method, then ease of operation is improved, but system reliability deteriorates due to duplicated IDs
Solution Approach 1:
The patent implements a self-service mechanism where the network node automatically determines and allocates PDU session IDs based on terminal device identifiers and tracking of previously allocated IDs. This automated self-service approach eliminates the need for manual ID assignment while ensuring uniqueness and maintaining system reliability
Data Source
AI summary
Embodiments include method performed at a network node of a communication network, as well as network nodes configured to perform such methods. These methods include selecting, for a terminal device, a protocol data unit session identity (PDU) session identifier (ID) from a group of PDU session IDs that are not allocated to the terminal device by the communication network. In some embodiments, the group of PDU session IDs are not selectable by terminal devices. In some embodiments, the group of PDU session IDs are exclusive of a second group of PDU session IDs that are selectable by terminal devices. In some embodiments, the PDU session ID may be selected based on an evolved packet system (EPS) bearer ID and one of various mappings.