VoIP Emergency Call Routing via Location Server Intermediary

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Solution Overview

Problem

Current wireless communication networks face challenges in routing emergency Voice-over-Internet Protocol (VoIP) calls, especially for users without a service subscription or roaming agreements, as they struggle to accurately determine the appropriate Public Safety Answering Point (PSAP) and provide location information.

Innovation Solution

The method involves a User Equipment (UE) interacting with a visited network to establish an emergency VoIP call by obtaining a position estimate from a location server, allowing the call to be routed to a selected PSAP, with mechanisms to handle UEs without service subscriptions or roaming agreements, and providing updated location information as needed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a user without service subscription or roaming agreement places an emergency VoIP call, then the call can be established, but the network cannot accurately determine the appropriate PSAP for routing

Engineering Contradiction:
Improveemergency call support for unsubscribed usersVSAvoidlocation information for PSAP routing
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent introduces a Location Server as an intermediary component that the UE interacts with to obtain position estimates. This mediator resolves the contradiction by providing location information without requiring service subscription, enabling PSAP routing for emergency calls from unsubscribed users while maintaining accurate location data

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the network obtains an interim position estimate for routing, then the PSAP can be determined, but the location accuracy may be insufficient for updated positioning requirements

Engineering Contradiction:
Improveemergency call routing efficiencyVSAvoidposition estimate accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent implements preliminary action by obtaining an interim position estimate quickly for immediate PSAP routing, then performing subsequent positioning to obtain updated, more accurate position estimates. This two-stage approach resolves the contradiction by first ensuring rapid call routing efficiency, then improving location precision when needed

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs feedback mechanisms where the PSAP can request updated location information after the initial call is routed using the interim position estimate. The network then performs additional positioning and provides updated position estimates back to the PSAP, resolving the contradiction between initial routing efficiency and subsequent location precision requirements

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP1911257B1VOIP emergency call support
Publication Date: 2018.06.06 QUALCOMM INC
  • EP1911257B1 patent drawingFigure 1
  • EP1911257B1 patent drawingFigure 2
  • EP1911257B1 patent drawingFigure 3

AI summary

Techniques to support emergency voice-over-Internet Protocol (VoIP) calls are described. The techniques may be used for various 3GPP and 3GPP2 networks, various location architectures, and various types of User Equipment (UE). A UE communicates with a visited network to send a request to establish an emergency VoIP call. The UE interacts with a location server instructed by the visited network to obtain a first position estimate for the UE. The UE performs call setup via the visited network to establish the emergency VoIP call with a PSAP, which may be selected based on the first position estimate. The UE may thereafter perform positioning with the location server to obtain an updated position estimate for the UE, e.g., if requested by the PSAP.