Prioritized Call Setup in Mobile Network Overload

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Solution Overview

Problem

Existing methods for maintaining network access during mobile radio network overload, such as those during major events or disasters, often result in non-prioritized subscribers being blocked, and existing solutions like eMLPP and access class barring are cumbersome or impractical, especially for emergency services trying to establish calls.

Innovation Solution

A method that allows a prioritized mobile radio terminal to set up a connection with a non-prioritized terminal by recognizing prioritized calls and temporarily lifting access class blocking, either network-side or device-side, ensuring prioritized calls can be accepted even during overload, without overwhelming the network.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If access class barring is used to manage network overload by blocking non-prioritized terminals, then network reliability for prioritized services is improved, but network accessibility for non-prioritized terminals deteriorates

Engineering Contradiction:
Improvenetwork reliabilityVSAvoidnetwork accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The blocking status of access classes is made dynamic rather than static. The network can temporarily lift the blocking of a specific access class when a prioritized terminal needs to establish a call to a terminal in that class. This allows the system to adapt between maintaining block restrictions and enabling specific connections based on priority needs, resolving the contradiction between reliability and accessibility.

Inventive Principle:
Principle #15Dynamics

2Reliability

If eMLPP is used to prioritize calls, then call setup priority is improved, but device complexity and implementation difficulty increase

Engineering Contradiction:
Improvecall setup priorityVSAvoidimplementation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the priority recognition and blocking management functionality from the terminal device and places it entirely in the network infrastructure (specifically the MSC). The terminal only needs to indicate its access class, while the network handles all complex logic of recognizing prioritized calls, checking blocking status, and temporarily lifting blocks. This reduces terminal complexity while maintaining priority call capabilities.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If network blocking is lifted for non-prioritized terminals to accept prioritized calls, then call establishment success is improved, but network load increases

Engineering Contradiction:
Improvecall establishment successVSAvoidnetwork load
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

Instead of lifting blocking for all access classes or all terminals, the patent applies partial action by temporarily lifting the blocking only for the specific access class of the called terminal when needed for a prioritized call. This minimal intervention allows the prioritized call to succeed while keeping other terminals blocked, thus avoiding excessive network load increase while achieving call establishment success.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP2220879B1Method for connecting prioritized incoming calls in overload situations in a mobile communications network
Publication Date: 2018.09.12 DEUTSCHE TELEKOM AG

AI summary

The invention relates to a method for connecting a mobile communications connection in a mobile communications network, particularly in a cellular mobile communications network, in the case of temporarily limited accessibility or availability of the mobile communications network due to an overload, between a prioritized first mobile communications terminal device and a non-prioritized second mobile communications terminal device, wherein the non-prioritized mobile communications terminal device is at least partially and at least temporarily blocked due to the overload situation, wherein the first prioritized mobile communications terminal device transmits a call connection attempt, the mobile communications network recognizes the call connection attempt as a prioritized call connection attempt and prioritizes said attempt over other, non-prioritized mobile communications terminal devices and transmits said attempt to the second non-prioritized mobile communications terminal device, wherein the blockage of the second mobile communications terminal device is at least temporarily lifted such that the incoming call may be accepted by the second mobile communications terminal device and the mobile communications connection may be made, the blockage of the second mobile communications terminal device being particularly lifted on the network side or the second mobile communications terminal device particularly having means for recognizing that the call connection attempt is originating from a prioritized mobile communications terminal device and at least temporarily ignoring the blockage thereof.