5G V2X Congestion Control Using CBR-Based Transmission Adaptation

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Solution Overview

Problem

Existing V2X systems face challenges in effectively managing congestion and interference in high-load scenarios, particularly in vehicle-to-everything communications, where current resource reselection algorithms fail to adequately support low-latency and high-reliability communications between high-speed devices.

Innovation Solution

A congestion control method and device that utilize Channel Busy Ratio (CBR) measurements to dynamically adjust transmission parameters, such as the number of occupied subchannels, Modulation and Coding Scheme (MCS), and transmission power, based on priority and system load, to minimize interference and optimize performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If resource reselection algorithms are used in high-load scenarios, then communication coverage is maintained, but congestion and interference increase, degrading transmission reliability

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidcongestion and interference
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements dynamic adjustment of transmission parameters (MCS, subchannel allocation, power control) based on real-time CBR measurements and priority levels. The system continuously adapts resource allocation strategies according to current channel conditions and traffic priorities, transforming static resource allocation into a dynamic response mechanism that maintains reliability under varying congestion conditions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes multiple transmission parameters simultaneously based on CBR thresholds: MCS index adjustment, subchannel occupation ratio modification, and power spectral density control. These parameter changes enable the system to operate reliably across different congestion levels by optimizing the trade-off between transmission rate and interference management

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If transmission parameters are adjusted to reduce congestion, then interference is minimized, but transmission speed and data rate decrease

Engineering Contradiction:
ImproveinterferenceVSAvoidtransmission speed
Core Design Contradiction:
Object-affected harmful factorsVSSpeed

Solution Approach 1:

The patent applies different transmission parameter adjustments to different priority levels of traffic. High-priority traffic receives more aggressive interference mitigation (lower MCS, fewer subchannels) while low-priority traffic can tolerate higher interference for maintained data rates. This local differentiation allows interference reduction without uniformly sacrificing transmission speed across all traffic types

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements partial resource allocation adjustment based on CBR thresholds. Instead of always operating at maximum capacity, the system selectively reduces resources only when CBR exceeds thresholds, maintaining full transmission speed when conditions permit while achieving interference reduction when necessary

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If Channel Busy Ratio measurements are performed frequently to detect congestion, then congestion detection accuracy improves, but device energy consumption increases

Engineering Contradiction:
Improvecongestion detection accuracyVSAvoiddevice energy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic CBR measurements at defined intervals (e.g., every 100ms or at specific subframe boundaries) rather than continuous monitoring. This periodic approach maintains adequate congestion detection accuracy while significantly reducing energy consumption compared to continuous measurement, finding an optimal balance between measurement precision and power usage

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent leverages existing sensing and measurement infrastructure already present in V2X devices for other purposes (channel quality estimation, resource selection). By reusing these existing measurement capabilities for CBR calculation, the system achieves accurate congestion detection without requiring additional dedicated measurement hardware or energy-intensive separate measurement processes

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3504897B1Method and device for controlling congestion
Publication Date: 2026.02.18 SAMSUNG ELECTRONICS CO LTD
  • EP3504897B1 patent drawingFigure 1~2
  • EP3504897B1 patent drawingFigure 3~5
  • EP3504897B1 patent drawingFigure 6~8

AI summary

The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The present disclosure provides a method for controlling congestion, including: a User Equipment (UE) measures a Channel Busy Ratio (CBR), and controls congestion based on the CBR and a priority; the UE transmits Scheduling Assignment (SA) indicating data channel resources, and correspondingly transmits data.