Access Network Selection for Dual Mode User Equipment
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Solution Overview
Problem
Current wireless communication systems face limitations in selecting an access network for dual mode User Equipment (UE) using a Trusted WLAN Access Network (TWAN), restricting simultaneous connection through the TWAN and the core network due to IP address allocation constraints.
Innovation Solution
A method and device for a UE to determine if packet service can be performed through a WLAN, allowing WLAN selection or reselection as a candidate for access network, based on predetermined rules such as IFOM, MAPCON, or NSWO, considering factors like load, signal strength, and user preferences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a dual mode UE uses a Trusted WLAN Access Network (TWAN) for packet service, then the UE can connect to the WLAN access network, but the UE cannot simultaneously support both IP address allocation from the core network and IP address allocation from the WLAN access point
Solution Approach 1:
The patent segments the access network selection process into distinct scenarios: trusted non-3GPP access (TWAN) and untrusted non-3GPP access. For TWAN, the system allocates IP addresses from the core network (S2a interface), while for untrusted access, it uses IP addresses from the WLAN access point. This segmentation resolves the contradiction by providing different IP allocation mechanisms for different access types, enabling adaptability without overwhelming complexity.
Solution Approach 2:
The patent introduces the S2a interface as an intermediary between the TWAN and the core network (PDN Gateway). This intermediary enables the UE to obtain IP addresses from the core network when accessing via TWAN, bridging the gap between WLAN access and core network services. The S2a interface acts as a mediator that allows simultaneous support for TWAN connection and core network IP allocation, resolving the technical contradiction.
2Productivity
If the UE selects WLAN as the access network for packet service, then the UE can utilize WLAN resources, but connection through TWAN and connection through the core network cannot be performed at the same time
Solution Approach 1:
The patent implements dynamic access network selection based on the type of WLAN access. When the UE detects a trusted WLAN (TWAN), it dynamically switches to use the S2a interface for core network connection, enabling both WLAN resource utilization and core network connectivity. The system dynamically adjusts the IP allocation source and connection path based on the access network type, resolving the contradiction between productivity and reliability.
Solution Approach 2:
The patent changes the parameter of IP address allocation source based on the access network type. For trusted WLAN access, the IP address is allocated from the core network PDN Gateway via the S2a interface. For untrusted access, the IP address is allocated from the WLAN access point. This parameter change enables the system to maintain both high productivity (WLAN usage) and reliability (core network connection) simultaneously.
3Ease of operation
If the UE uses a single IP address allocation source (either core network or WLAN access point), then the IP address management is simplified, but the UE cannot perform packet service through both TWAN and core network simultaneously
Solution Approach 1:
The patent makes the IP address allocation system universal by supporting multiple allocation sources depending on the access network type. The system can allocate IP addresses from the core network PDN Gateway when accessing via TWAN, and from the WLAN access point for untrusted access. This multi-functionality enables the system to maintain operational simplicity while achieving simultaneous connection capability through different access types.
Solution Approach 2:
The patent performs preliminary determination of the access network type (trusted vs. untrusted) before initiating IP address allocation. Based on this preliminary action, the system pre-configures the appropriate IP allocation source and connection path. This preliminary action simplifies the overall operation by avoiding complex real-time decisions, while still enabling versatile simultaneous connections through different access networks.
Data Source
AI summary
The present invention relates to a wireless communication system, and more specifically, a method and a device for selecting an access network are disclosed. A method by which a terminal selects an access network in a wireless communication system, according to one embodiment of the present invention, can comprise the steps of: determining whether a packet service can be performed through a wireless LAN (WLAN) in use when the packet service is set to select a WLAN access network as an access network of the terminal for the packet service according to a predetermined rule while the terminal is using the WLAN; and performing an access network selection operation including a WLAN selection or a WLAN reselection as a candidate on the basis of the result of the determination step.