Wireless Emergency Call Routing Using Variable Location Delay
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems fail to accurately route wireless emergency calls to the appropriate Public Safety Answer Point (PSAP) due to insufficient time for user equipment (UE) to generate a fresh location, leading to potential delays and incorrect routing.
Innovation Solution
Implementing a variable delay timer mechanism that adjusts the time to send a SIP INVITE message based on the age of the cached location, allowing for a fresh location to be acquired before routing the emergency call to the PSAP, thereby ensuring accurate location-based routing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the UE sends the SIP INVITE message immediately using cached location, then the call routing speed is improved, but the location accuracy deteriorates
Solution Approach 1:
The system performs preliminary location updates by triggering a fresh location acquisition when the cached location age exceeds a threshold before the SIP INVITE is sent. This ensures location accuracy is maintained without requiring immediate location updates for every call initiation.
Solution Approach 2:
The patent implements dynamic timing adjustment by varying the delay duration based on the age of the cached location. The delay timer is dynamically set to different values (e.g., 2 seconds, 4 seconds, 6 seconds) depending on how stale the cached location is, optimizing the balance between speed and accuracy in real-time.
2Measurement precision
If a delay timer is introduced to acquire fresh location, then the location accuracy is improved, but the call routing time increases
Solution Approach 1:
The system changes the timing parameter dynamically based on the cached location age. Instead of using a fixed delay, the delay timer value is adjusted according to how stale the location data is, ensuring minimal delay when location is fresh and appropriate delay when location needs updating.
Solution Approach 2:
The patent applies partial action by only triggering fresh location acquisition when necessary (when cached location age exceeds threshold). Not every call initiation requires a fresh location update, so the system selectively applies the delay timer only when needed, reducing overall time loss.
3Productivity
If the cached location is used without verification, then the call routing speed is improved, but the routing accuracy to appropriate PSAP deteriorates
Solution Approach 1:
The system implements feedback by monitoring the age of the cached location and using this information to determine whether a fresh location update is needed before routing. This feedback mechanism ensures routing accuracy is maintained while minimizing unnecessary delays for recent location data.
Data Source
AI summary
Systems and methods are provided for routing wireless emergency calls to an appropriate public safety answer point (PSAP). When an emergency call is initiated by user equipment (UE), an age of the cached location of the UE is determined. Based on the age of the cached location, a variable delay timer is assigned for communicating a session information protocol (SIP) INV message comprising a location of the UE to a gateway. The location, in various aspects either the cached location or the fresh location, is communicated to the gateway, enabling the UE to communicate with the PSAP.