Disaster Condition Indication in Serving PLMN

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

During disasters, cellular networks often become overloaded or unavailable, leading to service denials due to congestion and network failures, as users attempt to contact emergency services simultaneously, and conventional solutions fail to effectively mitigate these issues.

Innovation Solution

A disaster condition indication mechanism is implemented in communication systems, where network nodes transmit control messages to client devices to inform them of a serving PLMN's disaster status, enabling the devices to initiate PLMN selection procedures and switch to alternative networks, even if they are normally forbidden, thereby minimizing service interruptions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If users remain on the home PLMN during a disaster, then normal service restrictions apply, but service continuity is lost when the network becomes unavailable

Engineering Contradiction:
Improveservice continuityVSAvoidPLMN selection flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system performs preliminary actions by pre-configuring alternative PLMNs in the UE's forbidden PLMN list before a disaster occurs. When a disaster is detected, the UE already has prepared alternative networks it can switch to, eliminating the need for real-time PLMN selection decisions during the crisis.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The network provides feedback to the UE about the disaster condition through control messages. This feedback mechanism enables the UE to detect that its serving PLMN is experiencing disaster conditions and automatically initiate PLMN reselection to alternative networks, ensuring service continuity.

Inventive Principle:
Principle #23Feedback

2Reliability

If the UE follows normal PLMN selection rules, then forbidden PLMNs are not selected, but service availability is reduced during disasters

Engineering Contradiction:
Improveservice availabilityVSAvoidPLMN management complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system dynamically adjusts PLMN selection behavior based on disaster conditions. Under normal conditions, the UE follows standard PLMN selection rules and avoids forbidden PLMNs. When a disaster is detected, the system temporarily modifies the selection criteria to allow access to previously forbidden PLMNs, ensuring service availability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameter of PLMN selection flexibility by modifying the forbidden PLMN list status. During disasters, the UE is configured to treat certain PLMNs as acceptable alternatives, effectively changing the selection parameters to prioritize service availability over normal roaming restrictions.

Inventive Principle:
Principle #35Parameter changes

3Loss of information

If the network does not provide disaster indication, then normal network operation is maintained, but user awareness of network status is insufficient

Engineering Contradiction:
Improvenetwork status informationVSAvoiduser operation simplicity
Core Design Contradiction:
Loss of informationVSEase of operation

Solution Approach 1:

The network provides feedback to users about disaster conditions through control messages sent to the UE. This feedback mechanism ensures users are informed about network status without requiring them to actively monitor or investigate network conditions, maintaining ease of operation while eliminating information loss.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4245047B1Disaster condition indication of serving plmn
Publication Date: 2025.03.26 HUAWEI TECH CO LTD
  • EP4245047B1 patent drawingFigure 1~2
  • EP4245047B1 patent drawingFigure 3~4
  • EP4245047B1 patent drawingFigure 5~6

AI summary

The invention relates to a novel mechanism involving a network node (100) and a client device (300) for indicating that a serving PLMN (610) is in a disaster condition. The network node informs the client device through control signalling (510) that the serving PLMN for the client device is in disaster condition. Thereby, the client device may take suitable measures so as to avoid service interruption, e.g. by registration at a visiting PLMN (620) not in disaster condition by initiating a PLMN selection procedure. Examples of control signalling that may be used in this context is SIB, NAS, RRC messages or paging messages. Furthermore, the invention also relates to corresponding methods and a computer program.