Emergency Signal Handling in Shared-Frequency Non-Terrestrial Networks

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Solution Overview

Problem

Non-terrestrial cellular networks operating on the same frequency as terrestrial networks experience interference, limiting their geographical coverage for emergency calling and messaging services.

Innovation Solution

A non-terrestrial cellular network operates in a minimal configuration to minimize interference with terrestrial networks, listening for emergency signals in a reduced bandwidth, and switches to a higher activity configuration upon receiving an emergency signal to handle the call.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the non-terrestrial network operates in full configuration to provide emergency services, then emergency service coverage is improved, but interference with the terrestrial network increases

Engineering Contradiction:
Improveemergency service coverageVSAvoidinterference with terrestrial network
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The non-terrestrial network dynamically switches between minimal configuration (during normal operation) and higher activity configuration (when emergency signal is detected). This dynamic reconfiguration allows the system to provide emergency services when needed while minimizing interference during normal operation, resolving the contradiction between emergency service coverage and interference with terrestrial networks.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The network changes its operational parameters (bandwidth, power level, configuration mode) based on the detected signal type. When an emergency signal is detected, the system transitions from minimal configuration parameters to higher activity parameters, enabling emergency service provision while managing interference through parameter control.

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If the non-terrestrial network operates in minimal configuration to reduce interference, then interference with terrestrial network is reduced, but emergency service capability is limited

Engineering Contradiction:
Improveinterference with terrestrial networkVSAvoidemergency service capability
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The system performs preliminary detection of emergency signals while operating in minimal configuration. This preliminary action allows the system to maintain low interference during normal operation while being prepared to quickly transition to full emergency service capability when an emergency signal is detected, thus resolving the contradiction between reduced interference and emergency service capability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The network dynamically adjusts its configuration based on detected signal types. The system transitions from minimal configuration to higher activity configuration upon detecting an emergency signal, ensuring that emergency service capability is available when needed while maintaining reduced interference during normal operation.

Inventive Principle:
Principle #15Dynamics

3Productivity

If the non-terrestrial network uses the same frequency as the terrestrial network, then frequency spectrum utilization is improved, but interference between networks occurs

Engineering Contradiction:
Improvefrequency spectrum utilizationVSAvoidinterference between networks
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The non-terrestrial network operates periodically in minimal configuration during normal operation and transitions to higher activity configuration only when emergency signals are detected. This periodic/demand-based operation pattern allows efficient frequency spectrum utilization while minimizing continuous interference with the terrestrial network.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system changes its operational parameters (power level, configuration mode, bandwidth) based on the operational state. By using parameter changes, the network achieves efficient spectrum utilization in minimal configuration while controlling interference through parameter adjustment when transitioning to emergency mode.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4432578B1Handling emergency signals in a cellular network
Publication Date: 2026.05.06 VODAFONE GROUP SERVICES LTD
  • EP4432578B1 patent drawingFigure 1
  • EP4432578B1 patent drawingFigure 2
  • EP4432578B1 patent drawingFigure 3

AI summary

An emergency signal is handled at a first network operated as a non-terrestrial cellular network. The first network operates on a same frequency as a second network, operated as a terrestrial cellular network. The first network is operated in a lower activity configuration, in which interference from the first network to the second network permits normal operation of the second network. In response to receiving the emergency signal from a user equipment at the first network, the first network is set to a higher activity configuration, causing increased interference from the first network to the second network than in the lower activity configuration.