Roaming Location Services via Visited Network Intermediary
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Solution Overview
Problem
Providing location services to mobile stations while roaming outside their home network is challenging, as existing systems face difficulties in ensuring seamless communication and accurate positioning across different wireless networks.
Innovation Solution
The system supports location services by establishing a network architecture that includes visited, home, and requesting networks, utilizing entities like Serving Position Determining Entities (S-PDEs), Serving Mobile Positioning Centers (S-MPCs), and Home Mobile Positioning Centers (H-MPCs) to facilitate roaming mobile stations, enabling methods such as gpsOne positioning and cell/sector positioning through specific message flows and interfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If location services are provided to roaming mobile stations using existing home network architecture, then location determination is possible, but service continuity and positioning accuracy deteriorate due to network boundary crossings
Solution Approach 1:
The patent introduces a Visited Network MPC as an intermediary entity between the Home Network MPC and the roaming mobile station. This intermediary facilitates seamless location service continuity by receiving positioning requests from the home network, coordinating with visited network entities (S-PDE, S-MPC), and forwarding results back to the home network, thereby resolving the service disruption issue at network boundaries without requiring complete architectural redesign
Solution Approach 2:
The patent segments the location services architecture into distinct functional components: Home Network MPC for subscription management, Visited Network MPC for roaming coordination, Serving Position Determining Entities for actual positioning calculations, and Serving Mobile Positioning Centers for local service execution. This segmentation allows each component to operate independently and specialize in specific functions, improving overall system reliability while managing complexity through modular design
2Measurement precision
If multiple positioning methods (gpsOne, cell/sector) are supported for roaming stations, then positioning accuracy improves, but system complexity and message flow requirements increase
Solution Approach 1:
The patent designs the Visited Network MPC and S-MPC entities to be universal, capable of handling multiple positioning methods (gpsOne, cell/sector) through a unified interface. The same core architecture and message flows can accommodate different positioning techniques by simply changing the underlying measurement and calculation mechanisms, eliminating the need for separate dedicated systems for each positioning method while maintaining high accuracy
Solution Approach 2:
The patent employs parameter changes to switch between different positioning methods. The system uses configurable parameters such as positioning method selection, accuracy requirements, and network capabilities to dynamically choose between gpsOne, cell/sector, or other positioning techniques. This parameter-driven approach allows flexible adaptation to different roaming scenarios without increasing architectural complexity, as the same framework simply adjusts operational parameters rather than structural elements
Data Source
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AI summary
Techniques for supporting location services with roaming are described. A mobile station interacts with a home mobile positioning center (H-MPC) in a home network for location services even when roaming. The mobile station communicates with a visited network for a data session and receives a request for its location. The mobile station sends first information (e.g., SID and NID) indicative of its current network location to the H-MPC. The H-MPC determines a serving mobile positioning center (S-MPC) in the visited network based on the first information. The S-MPC determines a serving position determining entity (S-PDE) in the visited network based on the first information. Depending on the selected positioning method, the H-MPC may receive an S-PDE address or a position estimate of the mobile station from the S-MPC and may forward this information to mobile station. The mobile station may communicate with the S-PDE for positioning using the S-PDE address.