Private Access Channel Frequency Hopping Against Denial-of-Service

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing land mobile communication systems face vulnerabilities to denial of service attacks due to public access channels with static characteristics, which are easily jammed and difficult to detect, and static scheduling methods are cumbersome and incompatible with mobility and scalability in satellite communications.

Innovation Solution

A method for generating a random access key defining a frequency hopping law for a private access channel, using a predetermined rule to allocate radio resources, ensuring only authorized equipment can access and communicate, making the channel characteristics unknown to malicious actors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a public access channel with static characteristics is used, then access is simple and standardized, but the system becomes vulnerable to denial of service attacks and easy to jam

Engineering Contradiction:
Improveaccess simplicityVSAvoidresistance to denial of service attacks
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies frequency hopping to dynamically change the access channel characteristics over time. The channel frequency varies according to a hopping pattern known to authorized terminals, making the channel invisible and unpredictable to jammers while maintaining standardized access procedures for legitimate users.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the frequency parameter of the access channel dynamically. By varying the operating frequency according to a predetermined hopping pattern, the system transforms a static vulnerable channel into a dynamic resilient channel that is difficult to target for denial of service attacks.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a static unpublished access channel is used, then robustness against denial of service is improved, but the channel becomes detectable and requires cumbersome planning

Engineering Contradiction:
Improverobustness against denial of serviceVSAvoidplanning complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses a universal frequency hopping pattern that can be applied across multiple access channels and network configurations. The same hopping algorithm serves both single-satellite and multi-satellite scenarios, as well as different network densities, eliminating the need for separate planning for each configuration.

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

Solution Approach 2:

The dynamic frequency hopping prevents the channel from being statically mapped or predicted. The hopping pattern ensures that the access channel occupies different frequencies at different times, making it undetectable to external observers while maintaining systematic resource allocation.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If static scheduling of terminals is used, then access control is simplified, but the system becomes incompatible with mobility and scaling

Engineering Contradiction:
Improveaccess control simplicityVSAvoidcompatibility with mobility and scaling
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic resource allocation where terminals autonomously select available resources based on current network conditions. The frequency hopping pattern adapts to different numbers of terminals and satellite configurations, allowing the system to scale from single-user to many-users without reconfiguring the fundamental access mechanism.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Terminals autonomously determine their own access timing and frequency based on the hopping pattern and current channel conditions. This self-service approach eliminates the need for centralized scheduling while maintaining order and avoiding collisions, enabling the system to adapt to mobility and scaling automatically.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4580075A1Communication within a private access channel
Publication Date: 2025.07.02 THALES SA
  • EP4580075A1 patent drawingFigure 1
  • EP4580075A1 patent drawingFigure 2
  • EP4580075A1 patent drawingFigure 3

AI summary

The present invention relates to a method (10) for communicating within a private access channel comprising the following steps: - generation (12) of a random number suitable for being translated, according to a rule, into an access key to said private access channel defining a frequency hopping law comprising a plurality of time and frequency positions of the radio resources to be allocated, said rule being known by any equipment suitable for being authorized to access said channel and/or to control access thereto; - acquisition (14) and translation of said random number into said key; - using said key obtained from said random number, request (18) for access to said private access channel, and/or authorization (20) for access to said private access channel; and/or allocation (22), to said private access channel, of the radio resources defined by said access key; - communication (24) using said private access channel.