VoWiFi E911 Location Determination via SIP Geolocation Headers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Determining a caller's location during an emergency VoWiFi call is challenging due to the need for manual registration of civic addresses, which is time-consuming and may fail if not registered, especially when the user moves locations.
Innovation Solution
The system uses a calling device to determine a coarse location and insert it into a SIP message, with a location server generating assistance data for GPS measurements, allowing dynamic location determination without requiring repeated registration, enabling quick and accurate location identification for emergency responders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If manual registration of civic address is required for VoWiFi emergency calls, then the E911 system can obtain caller location information, but the process becomes time-consuming and fails when users move locations
Solution Approach 1:
The system performs preliminary location determination by obtaining coarse location information (such as cell tower location or WiFi access point location) before the emergency call is initiated. This preliminary action populates location fields in advance, so when an emergency call is made, the location information is already available immediately without requiring manual registration at that moment.
Solution Approach 2:
The system enables self-service location determination by automatically obtaining coarse location information from available sources (cell towers, WiFi access points, GPS) and using it to populate location fields. The user does not need to manually register their location; the device automatically determines and provides location information to the E911 system.
2Productivity
If coarse location information is used in SIP messages, then location determination speed improves, but initial location data must be obtained from external sources
Solution Approach 1:
The system uses multi-functionality by leveraging existing infrastructure elements (cell towers, WiFi access points, GPS satellites) that serve multiple purposes. These same infrastructure elements used for regular communication and navigation are also utilized for emergency location determination, eliminating the need for dedicated emergency location systems.
Solution Approach 2:
The patent introduces an intermediary approach by using coarse location information from external sources (cell tower locations, WiFi access point locations, GPS coordinates) as a mediator to determine the caller's position. This intermediary data is then combined with network information to derive the civic address, bridging the gap between physical location and address information.
Data Source
AI summary
A method may include receiving, a session initiation protocol (SIP) Invite message associated with a Voice over WiFi (VoWiFi) call made by a user device and determining if the SIP Invite message includes a geolocation header having location information associated with the user device. The method may also include in response to determining that the SIP Invite message includes a geolocation header having location information, initiating a location session with the user device and generating assistance data based on the location information, wherein the assistance data is to be used by the user device to generate assisted global positioning system (aGPS) measurements. The method may further include transmitting, to the user device and during the location session, the assistance data, receiving, from the user device, aGPS measurements based on the assistance data and determining, based on the aGPS measurements, a location of the user device.