Conference Bridge Handoff for Multi-Mode Mobile Stations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multi-mode mobile stations lack seamless network connectivity when moving from one wireless network to another, such as from WWAN to WLAN, leading to disruptions in calls due to inadequate coverage and bandwidth limitations.
Innovation Solution
A method and system utilizing conference bridges to facilitate handoffs between different wireless networks by establishing call legs through a conference bridge, allowing seamless switching from one network to another, and re-establishing dropped calls through a call control system and database association.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a multi-mode mobile station uses a single wireless network interface, then the device complexity is reduced, but the adaptability to different network coverage areas deteriorates
Solution Approach 1:
The mobile station is designed with multiple wireless network interfaces (e.g., WWAN and WLAN) that can operate independently or together, allowing the same device to adapt to different network types and coverage areas without requiring multiple separate devices
2Adaptability or versatility
If the mobile station switches networks manually, then the network selection flexibility is improved, but the call disruption increases
Solution Approach 1:
The system pre-establishes a conference bridge configuration before network switching occurs. When a handoff is needed, the conference bridge is already prepared to receive call legs from both the old and new networks, allowing seamless switching without call disruption
Solution Approach 2:
The conference bridge acts as an intermediary element between the mobile station and the call routing system. It temporarily holds and bridges call legs from different networks, enabling smooth handoffs by mediating the transition from one network to another without dropping the call
3Reliability
If the system establishes multiple call legs simultaneously, then the handoff reliability is improved, but the system complexity increases
Solution Approach 1:
The call connection is segmented into separate call legs that can be independently managed. One call leg connects to the current network while another connects to the target network, allowing the system to manage each connection separately and reliably without overwhelming complexity
Data Source
AI summary
A multi-mode mobile station includes a first interface for wireless communication with a wireless local area network (WLAN) and a second interface for wireless communication with a wireless wide area network (WWAN). The multi-mode mobile station is associated with a particular conference bridge, through which all calls to and from the multi-mode mobile station are routed. For example, when a call involving the multi-mode mobile is established via the WLAN, the call includes a WLAN call leg that extends from the conference bridge to the multi-mode mobile station via the WLAN. To effect a handoff during the call, a WWAN call leg is established between the multi-mode mobile station and the conference bridge via the WWAN. The conference bridge bridges the WLAN and WWAN call legs. To complete the handoff, the multi-mode mobile station drops the WLAN call leg and continues the call using the WWAN call leg.