WLAN Cellular Handover via Packet Data Gateway Tunnel
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Solution Overview
Problem
There is a need for seamless handover and service continuity between wireless local area networks (WLANs) and cellular networks as users roam, ensuring uninterrupted wireless communication services across different network types.
Innovation Solution
The method involves establishing a connection between a WTRU and a WLAN, then setting up a tunnel to an IP network through a packet data gateway, allowing for handover to a cellular network when signal quality degrades, with options to establish a new connection before or after breaking the WLAN connection, or maintaining both connections simultaneously.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a WTRU roams between WLAN and cellular networks, then network coverage and accessibility are improved, but service continuity and handover reliability deteriorate
Solution Approach 1:
The patent establishes a tunnel connection between the WTRU and the packet data gateway (PDG) before handover occurs. This preliminary setup ensures that a data path is already in place, allowing seamless switching between WLAN and cellular networks without interrupting service continuity. The tunnel is configured in advance so that when handover is needed, the data flow can be redirected immediately without establishing new connections during the transition.
2Adaptability or versatility
If handover between WLAN and cellular networks is performed, then network flexibility and roaming capability are improved, but connection stability and service reliability worsen
Solution Approach 1:
The patent introduces a packet data gateway (PDG) as an intermediary node that maintains the data tunnel endpoint in the network. This intermediary allows the WTRU to switch between different access networks (WLAN and cellular) while the tunnel remains anchored at the PDG, providing connection stability during handover. The PDG acts as a mediator that ensures continuous data path availability regardless of which access network the WTRU is currently connected to.
3Reliability
If tunnel connection is established before handover, then service continuity is improved, but system complexity and coordination requirements worsen
Solution Approach 1:
The patent creates a universal tunnel structure that can operate across different network types (WLAN and cellular networks). The tunnel is designed to be network-agnostic, allowing the same data path to carry traffic regardless of which access network is being used. This multi-functionality simplifies the handover process because the tunnel infrastructure itself doesn't need to change during handover, reducing the coordination complexity despite the improved service continuity.
Data Source
AI summary
A method and system for interworking between cellular networks and wireless local area networks (WLANs) are disclosed. At least one cellular network, at least one WLAN, and an IP network may be deployed. A wireless transmit/receive unit (WTRU) may establish a connection to a WLAN and a tunnel between an access point (AP) and a packet data gateway (PDG) may be established. The PDG may establish a tunnel to an IP network. The WTRU may invoke a service which is delivered through the WLAN. As signal quality from the AP degrades below a predetermined threshold, a handover from the WLAN to the cellular network may be performed. A new connection to the cellular network may be established either before or after breaking the current connection to the WLAN or the two connections may be maintained simultaneously.