Cell Identifier Segmentation for Multi-Group Access Control

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Solution Overview

Problem

Operators of closed subscriber group cells in cellular land mobile networks cannot enable network access for cell terminals from other groups or open networks due to lack of access to positive lists of authorized cell identifiers stored in cell terminals.

Innovation Solution

Cells emit multiple cell identifiers, allowing members of different closed subscriber groups and open networks to access services by matching with corresponding identifiers stored in cell terminals, enabling staggered authorizations and service differentiation based on group membership.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a cell uses a single cell identifier for closed subscriber group access control, then security and access restriction are maintained, but the operator cannot enable network access for cell terminals from other groups or open networks

Engineering Contradiction:
Improvenetwork access flexibilityVSAvoidcell identifier management
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The cell identifier is segmented into multiple independent identifiers (first cell identifier for primary CSG group, second cell identifier for secondary groups). This allows the cell to serve multiple closed subscriber groups simultaneously while maintaining access control security, as each identifier can be independently matched against positive lists in cell terminals.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cell is designed with multi-functionality by emitting multiple cell identifiers that can serve different purposes: the first identifier for primary CSG access, the second identifier for additional CSG groups or open network access. This universal approach allows a single cell to fulfill multiple access control functions without requiring separate cells for each group.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If a cell restricts access to a single closed subscriber group, then access control security is maintained, but service differentiation and staggered authorizations cannot be implemented

Engineering Contradiction:
Improveservice differentiation capabilityVSAvoidnumber of authorized groups
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The authorization mechanism is segmented by assigning different cell identifiers to different subscriber groups. The first cell identifier corresponds to a first group of cell terminals, while the second cell identifier corresponds to one or more other groups. This segmentation enables service differentiation where different groups can have different access rights and service levels.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different cell identifiers provide local quality variations in access control. Each identifier can be associated with specific service permissions, allowing the operator to grant different levels of access (e.g., full network access, limited services, emergency calls only) to different subscriber groups based on their specific needs and authorization levels.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If the operator does not have access to positive lists of authorized cell identifiers, then cell terminal security is preserved, but the operator cannot dynamically enable or disable access for different groups

Engineering Contradiction:
Improvedynamic access controlVSAvoidaccess authorization information
Core Design Contradiction:
Ease of operationVSLoss of information

Solution Approach 1:

The system uses preliminary action by pre-configuring multiple cell identifiers in the cell before operation. These identifiers are emitted continuously and are available for matching without requiring real-time access to positive lists. This allows the operator to enable or disable access for different groups by controlling which identifiers are emitted, without needing to access or modify the positive lists stored in cell terminals.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2342919B1Method for operating a closed subscriber group (CSG) cell for open network access
Publication Date: 2016.11.02 DEUTSCHE TELEKOM AG
  • EP2342919B1 patent drawingFigure 1

AI summary

Method for operating one or more cells (10) of a cellular mobile network, each cell (10) being identifiable by an emitted cell identifier (CSG_ID) use being limited/limitable to closed subscriber groups by the cell (10) having a corresponding identifier (CSG_ID) and the cell terminals (UEl, UE2, UE3) being registered in the respective cell (10) for use of the cellular mobile network services only after a positive matching with a positive list of authorized cell identifiers (CSG_ID1, CSG_ID2, CSG_ID3) which are stored in the cell terminal (UEl, UE2, UE3), the cell (10) emitting one or more further cell identifiers (CSG_ID2, CSG ID3) in parallel in addition to a first cell identifier (CSG_ IDl), and that registration in the cell (10) and use of network services can take place by a first closed subscriber group to which a first group of cell terminals (UEl) belongs, whose respective positive lists contain the first cell identifier (CSG_ID1), and that registration in the cell (10) and use of network services can take place by one or more further open or closed subscriber groups to which one or more other groups of cell terminals (UE2, UE3) belong whose positive lists contain one or more of said one or more further cell identifiers (CSG ID2, CSG ID3).