Li-Fi Access Control via Group-Based Server Authentication

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Solution Overview

Problem

Li-Fi communication systems face challenges in managing access to online services for multiple terminals and ensuring continuity of service during terminal mobility, as existing technologies do not effectively differentiate content delivery to subscribed and non-subscribed devices, nor provide seamless service access across different transmission devices.

Innovation Solution

A method is implemented where each transmission device is assigned a unique identifier and grouped, allowing the server to check previous access requests and ensure continuity of service by processing requests only if identifiers correspond to the same group, with encryption and decryption using private keys for subscriber terminals, and disconnection if identifiers do not match, enabling fine control over data streams and user access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If light modulation is used for data transmission, then communication speed is improved, but service continuity during terminal mobility deteriorates

Engineering Contradiction:
Improvecommunication speedVSAvoidservice continuity
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The server performs preliminary authentication and groups transmission devices before mobility occurs. When a terminal moves between devices in the same group, service continuity is maintained without requiring re-authentication, thus preserving reliability while maintaining high communication speed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The server acts as an intermediary that manages authentication and groups transmission devices. This intermediary coordinates between terminals and transmission devices, enabling seamless service continuity during mobility while maintaining the high-speed light modulation communication.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of information

If individual device addressing is used, then content differentiation for subscribed terminals is improved, but system complexity increases

Engineering Contradiction:
Improvecontent differentiationVSAvoidsystem complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The system segments transmission devices into groups based on subscription status and service entitlements. This segmentation enables differentiated content delivery to subscribed versus non-subscribed terminals while simplifying the addressing mechanism compared to purely individual device addressing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The group identifier serves multiple functions: it differentiates between subscribed and non-subscribed devices, enables content differentiation, and provides a simplified addressing mechanism. This multi-functionality reduces system complexity while maintaining the ability to deliver differentiated content.

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

3Reliability

If authentication is performed at each device change, then access security is improved, but service continuity deteriorates

Engineering Contradiction:
Improveaccess securityVSAvoidservice interruption time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

Authentication is performed preliminarily when the terminal first connects to a transmission device. The server then maintains this authentication state across device changes within the same group, eliminating the need for repeated authentication and thus maintaining security while preventing service interruption.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The authentication state is maintained continuously across device changes within the same group. This continuity of the authenticated state allows the terminal to move between devices without interruption, preserving both security and service continuity.

Inventive Principle:
Principle #20Continuity of useful action

4Ease of operation

If group-based access control is implemented, then service management is improved, but access flexibility for mobile terminals deteriorates

Engineering Contradiction:
Improveservice managementVSAvoidaccess flexibility
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

Transmission devices are segmented into groups with different service entitlements. This segmentation simplifies service management by allowing administrators to control access at the group level while still enabling flexible terminal movement within authorized groups.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adapts to terminal mobility by allowing terminals to move between transmission devices within their authorized group without re-authentication. This dynamic behavior maintains access flexibility while preserving the simplified group-based management structure.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution ensures secure, continuous access to online services for subscribed terminals and manages distinct content delivery across different transmission devices, maintaining service integrity during terminal mobility by using group identifiers and encryption, thereby enhancing user experience and service management.

Implementation Method 1

data transmission devices using light modulation to produce a light beam

Methodology Applied
Scientific EffectLight modulation:

Implementation Method 2

terminals D1, D2, and D3, positioned under the light beam, are equipped with a photodetector coupled to an integrated digital demodulator

Methodology Applied
Scientific EffectPhotodetection: Photoelectric Effect

Data Source

PatentEP3391561B1Control of access to an on-line service via a li-fi network
Publication Date: 2020.11.18 ORANGE SA
  • EP3391561B1 patent drawingFigure 1
  • EP3391561B1 patent drawingFigure 2
  • EP3391561B1 patent drawingFigure 3

AI summary

The invention relates to control of access to an on-line service, the access to the service being requested, via a communication network, by a terminal (SM) suitable for receiving data broadcast by a plurality of devices for data transmission by light modulation producing a light beam. In particular: each transmission device is characterised by a unique identifier (ID1, …, ID7); and each transmission device belongs to a group of devices (GP1, GP2, GP3). The following steps, carried out by a server connected to the transmission devices, are provided: upon receiving a request from the terminal to access the service via a second transmission device identified by a second identifier (ID3), verifying whether a previous access request for said same terminal was accepted for a first transmission device identified by a first identifier (ID2); and, when the first and second identifiers correspond to devices of the same group (GP1), processing the access request.