Weighted-Fair Message Rate Congestion Control for Vehicular Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing message rate based congestion control strategies in vehicular communication systems cannot achieve different steady message rates for various vehicles, such as ambulances and police cars, which require higher transmission rates due to their higher speeds and accident proneness.
Innovation Solution
A system and method for implementing congestion control based on weighted fair message rates, calculated in a distributed manner using a measurement module, calculation module, and determination module, which measures channel busy ratios, calculates ratio errors, and determines message rates for vehicles based on weight ratios, allowing for different steady state message rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing message rate based congestion control strategies are used, then all vehicles converge to the same steady state message rate, but emergency vehicles (ambulances, police cars) cannot transmit messages at higher rates despite their higher speeds and accident proneness
Solution Approach 1:
The patent assigns different weight factors to different vehicle types (e.g., emergency vehicles vs. private vehicles), allowing each vehicle category to have customized message rate characteristics. This enables emergency vehicles to maintain higher message rates while private vehicles use lower rates, achieving local optimization for specific vehicle types.
Solution Approach 2:
The patent introduces weight factors as adjustable parameters that modify the message rate calculation for different vehicles. By changing these weight parameters, the system can dynamically adjust steady-state message rates to match the specific needs of different vehicle types, particularly enabling emergency vehicles to transmit at higher rates.
2Reliability
If message rates are increased for emergency vehicles, then transmission reliability improves, but communication congestion on DSRC channels worsens
Solution Approach 1:
The patent applies different weight factors to different vehicle types, allowing emergency vehicles to receive higher message rates while private vehicles use lower rates. This localized differentiation ensures that only critical communications (from emergency vehicles) consume higher bandwidth, minimizing overall congestion while maintaining reliability for essential transmissions.
Solution Approach 2:
The patent implements a feedback mechanism where vehicles monitor channel conditions and adjust their message rates accordingly. The congestion control algorithm uses feedback from channel status to dynamically tune message rates, ensuring that emergency vehicles maintain high transmission rates when needed while preventing excessive congestion through adaptive rate adjustment.
Data Source
AI summary
A system and method for implementing congestion control for vehicles based at least in part on weighted fair message rates is disclosed. The system comprises a measurement module, a calculation module and a determination module. The measurement module measures a channel busy ratio describing a fraction of time during which a channel is busy. The calculation module calculates a ratio error by comparing the measured channel busy ratio with a target channel busy ratio. The determination module determines a first parameter value for a first vehicle based at least in part on a ratio of weights and determines a message rate for the first vehicle based at least in part on the ratio error and the first parameter value. The message rate describes a speed for transmitting messages from the first vehicle.