Emergency Call Re-establishment via Location Caching

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Emergency call re-establishment in radio communication networks is delayed due to UE location determination and reporting, which becomes inconvenient in situations where an emergency call is dropped, especially under bad radio conditions.

Innovation Solution

Implementing an emergency call re-establishment timer that allows the acceptance of a second emergency call if the UE's location is already known, and transmitting a UE location request only when necessary, thereby reducing delays in emergency call handling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If UE location determination and reporting is performed for every emergency call, then location accuracy is improved, but call setup time increases

Engineering Contradiction:

Improvelocation accuracyVSAvoidcall setup time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The system performs location determination in advance during the first emergency call and stores it. When a second emergency call is received within a predefined time period, the system reuses the previously determined location instead of performing a new location determination, thereby avoiding redundant time-consuming operations while maintaining location accuracy for emergency response.

Inventive Principle:

Principle #10Preliminary action

2Loss of information

If location request is transmitted for every emergency call, then location information is updated, but processing time increases

Engineering Contradiction:

Improvelocation information freshnessVSAvoidprocessing time

Core Design Contradiction:

Loss of informationVSLoss of time

Solution Approach 1:

The system determines and stores the UE location during the first emergency call setup. When a second emergency call is received within the predefined time period, the system checks whether to transmit a location request based on the stored location's validity, avoiding unnecessary location requests and reducing processing time while ensuring location information remains fresh and accurate.

Inventive Principle:

Principle #10Preliminary action

3Measurement precision

If emergency call re-establishment is performed with standard location determination, then location accuracy is maintained, but user convenience deteriorates

Engineering Contradiction:

Improvelocation accuracyVSAvoiduser convenience

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The system performs location determination during the first emergency call and retains it for subsequent calls within a predefined time period. This preliminary location determination eliminates the need for repeated location requests during re-establishment, significantly reducing delays and improving user convenience while maintaining sufficient location accuracy for emergency response purposes.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS9955327B2Accelerated re-establishment of emergency calls

Publication Date: 2018.04.24 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A method for emergency call handling for a User Equipment (UE). A UE performs a first emergency call. The UE also transmits a first UE location report. Furthermore, the UE performs a second emergency call. The UE re-transmits the first UE location report when it is determined that a change in a UE location (since the transmission of said first UE location report) is below a threshold value. Alternatively, the UE re-transmits the first UE location report when it is determined that a time period set by a timer has not expired, wherein the time period set by this timer is set upon transmission of the first location report. Otherwise, the UE transmits a second UE location report.