Trusted WLAN Interworking for Multiple PDU Sessions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current 3GPP standards limit Non-5G Capable over WLAN (N5CW) devices to a single Protocol Data Unit (PDU) session when connected to a trusted WLAN, lacking support for dynamic PDU session activation, deactivation, and address configuration, and do not facilitate multiple PDU sessions.
Innovation Solution
A lightweight alternative is provided through a Trusted WLAN Interworking Function (TWIF) that utilizes a UE Route Selection Policy (URSP) envelope to enable multiple PDU sessions by matching session parameters with URSP rules, allowing N5CW devices to establish and manage multiple PDU sessions via enhanced 802.11 signaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If current 3GPP standards are used for N5CW devices connected to trusted WLAN, then device compatibility and standard compliance are maintained, but multiple PDU sessions cannot be established and dynamic session management is not supported
Solution Approach 1:
The TWIF acts as an intermediary between the N5CW device and the mobile core network, performing NAS signaling operations on behalf of the device. The TWIF receives session activation triggers from the device, formulates appropriate NAS signaling messages, and communicates with the control plane function to establish, modify, or release PDU sessions. This mediator approach enables multiple PDU sessions for N5CW devices without requiring the devices themselves to support complex NAS signaling.
Solution Approach 2:
The session management functionality is segmented between the TWIF and the mobile core network. The TWIF handles device-specific session management tasks including receiving activation triggers, matching URSP rules, and initiating session procedures. The control plane function handles network-side session management. This segmentation allows N5CW devices to benefit from multiple PDU sessions while keeping device complexity low.
2Adaptability or versatility
If TWIF performs NAS signaling operations on behalf of N5CW devices, then multiple PDU sessions are enabled, but signaling overhead and network processing load increase
Solution Approach 1:
The TWIF performs preliminary actions by maintaining a cached copy of the URSP envelope received during device registration. When a session activation trigger is received, the TWIF can immediately match the trigger parameters against the cached URSP rules without needing to retrieve the full URSP envelope from the network each time. This preliminary caching significantly reduces session establishment time and network signaling overhead.
Solution Approach 2:
The TWIF autonomously performs NAS signaling operations based on locally cached URSP information and received activation triggers. The system serves itself by making local decisions about session management without requiring continuous network intervention, reducing both signaling overhead and processing delays.
3Reliability
If URSP rules are used for session parameter matching, then authorized sessions are ensured, but complexity of session parameter management increases
Solution Approach 1:
The TWIF serves as an intermediary that handles the complexity of URSP rule matching and session parameter validation. Instead of requiring N5CW devices to independently interpret and apply complex URSP rules, the TWIF receives simple activation triggers from devices, performs the sophisticated URSP matching against cached rules, and manages session parameters. This transfers the complexity burden from the device to the network side, maintaining authorization accuracy while simplifying device functionality.
4Adaptability or versatility
If N5CW devices support multiple PDU sessions via enhanced 802.11 signaling, then service flexibility is enhanced, but compatibility with existing WLAN infrastructure may be compromised
Solution Approach 1:
The patent extracts the complex session management functionality from the N5CW device and places it in the TWIF on the network side. The device only needs to send simplified activation triggers via standard or enhanced 802.11 signaling, while the TWIF handles all complex operations including URSP matching, NAS signaling formulation, and session management. This extraction maintains compatibility with existing WLAN infrastructure while enabling advanced multiple PDU session capabilities.
Data Source
AI summary
Provided herein are techniques to facilitate multiple sessions for a wireless device with a mobile core network via a trusted WLAN. In one example, a method may include obtaining, by an interworking function of a WLAN, an indication that a wireless device seeks to establish a session with the mobile core network, wherein the indication comprises first parameters associated with the session. The method may further include upon identifying, by the interworking function, that the first parameters match a route selection rule of a plurality of route selection rules for the wireless device, facilitating establishment of the session with the mobile core network based on the first parameters. In one instance, the wireless device is not capable of Non-Access-Stratum (NAS) signaling with the mobile core network via the WLAN.