Shared PLMN ID Roaming via Segmented User Identification

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Solution Overview

Problem

Current Professional Mobile Radio (PMR) networks require a large number of unique PLMN ID type network identifiers due to the large number of terminals and plethora of roaming agreements, making it difficult for users to roam between networks efficiently.

Innovation Solution

A method for attachment and authentication of user terminals that uses a shared network identifier code and a second user identification code, allowing a user terminal to access and authenticate with multiple networks using a single PLMN ID, while maintaining separate user rights and billing through a centralized database system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a unique PLMN ID is assigned to each network for every terminal and roaming agreement, then network identification precision is improved, but the quantity of network identifiers increases significantly

Engineering Contradiction:

Improvenetwork identification precisionVSAvoidquantity of network identifiers

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The user identification is segmented into two parts: a first identification (e.g., IMSI) that remains with the user terminal, and a second identification that is network-specific and stored in the visited network's database. This segmentation allows the system to maintain precise network identification while reducing the number of unique PLMN IDs needed, as the same first identification can be used across multiple networks with different second identifications.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension to network identification by using a two-tier identification system. Instead of relying solely on unique PLMN IDs for each network-user combination, the system adds a database-stored second identification that links the user's first identification to the visited network, effectively moving from a single-dimension PLMN ID system to a two-dimension identification approach.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If multiple unique PLMN IDs are used for different networks, then network security and insulation are improved, but the complexity of roaming management increases

Engineering Contradiction:

Improvenetwork security and insulationVSAvoidcomplexity of roaming management

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a database as an intermediary between the user terminal and the visited network. This database stores the second identification that links the user's first identification to the visited network, acting as a mediator that maintains security and insulation while simplifying roaming management. The database enables automatic authentication and network selection without requiring complex manual configuration of multiple PLMN IDs.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Quantity of substance

If a single PLMN ID is shared across multiple networks, then the quantity of network identifiers is reduced, but the precision of network identification decreases

Engineering Contradiction:

Improvequantity of network identifiersVSAvoidnetwork identification precision

Core Design Contradiction:

Quantity of substanceVSMeasurement precision

Solution Approach 1:

The identification system is segmented into a first identification (e.g., IMSI) that is shared across multiple networks and a second identification that is network-specific and stored in the visited network's database. This segmentation allows a single PLMN ID to be used across multiple networks while maintaining precise network identification through the database-stored second identification.

Inventive Principle:

Principle #1Segmentation

4Reliability

If traditional roaming with multiple PLMN IDs is used, then network security is maintained, but user mobility and roaming efficiency decrease

Engineering Contradiction:

Improvenetwork securityVSAvoiduser mobility and roaming efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The first identification (e.g., IMSI) serves multiple functions: it identifies the user terminal, enables authentication across multiple visited networks, and eliminates the need for multiple unique PLMN IDs. This multi-functionality improves user mobility and roaming efficiency while maintaining network security through the database-stored second identification that links the universal first identification to specific visited networks.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS10028138B2Method for attachment and authentication of a user terminal with a visited network

Publication Date: 2018.07.17 CASSIDIAN SAS

AI summary

A method for attachment and authentication of a user terminal of a home type radiocommunication network with a visited type radiocommunication network, the home network including home means for attachment to a packet network and the visited network including: at least one visited base station able to ensure radio transmission and reception with user terminals located in at least one visited cell attached to the visited base station; visited authentication and control means of user terminals able to authenticate the user terminals attached to the network; and at least one visited distribution gateway ensuring radio reception and transmission with the at least one visited base station.