WLAN Traffic Control via User Priority and Modulation Rate

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Solution Overview

Problem

Existing Wi-Fi systems lack effective mechanisms for user prioritization and fair bandwidth allocation, leading to inefficient resource utilization, as they treat all stations equally regardless of user priority or modulation rates, and fail to differentiate between public and private users in public Wi-Fi networks.

Innovation Solution

A traffic control system for wireless LANs that uses user priority and modulation rate detection to dynamically adjust air interface usage, ensuring fairer distribution of bandwidth by policing and shaping traffic based on user classes and modulation rates, without modifying the physical or MAC layer, and managing air interface utilization between public and private users.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If DCF mechanism is used to share radio channel resources, then all stations are treated equally with fair access chance, but user priority differentiation is lost and resource allocation is not optimized

Engineering Contradiction:
Improvefair accessVSAvoiduser priority differentiation
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent segments users into different categories (e.g., voice, video, best effort, background) based on priority levels. Each category is assigned different access parameters such as contention window sizes and inter-frame spaces, enabling differentiated service while maintaining the distributed coordination framework. This segmentation allows the system to simultaneously provide fair access to all stations while differentiating service quality based on user priority.

Inventive Principle:
Principle #1Segmentation

2Productivity

If stations transmit at their maximum modulation rate, then data throughput is maximized, but air interface resource consumption increases and fairness among stations is reduced

Engineering Contradiction:
Improvedata throughputVSAvoidair interface resource consumption
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent dynamically adjusts transmission parameters including modulation rate, contention window size, and inter-frame space based on station characteristics and current network conditions. By changing these parameters adaptively, the system optimizes the balance between data throughput and air interface resource consumption, preventing stations with high modulation rates from consuming excessive airtime while maintaining overall network efficiency and fairness.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If backhaul traffic flow rates are used for bandwidth protection, then private user bandwidth is protected, but air interface usage is not accurately accounted for

Engineering Contradiction:
Improvebandwidth protectionVSAvoidair interface usage measurement
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent implements feedback mechanisms where the access point monitors actual air interface usage by each station and adjusts bandwidth allocation accordingly. This feedback loop enables accurate measurement and accounting of air interface consumption, allowing the system to provide precise bandwidth protection to private users while fairly allocating resources based on actual usage patterns rather than just backhaul traffic flow rates.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2979485B1Method and system for controlling traffic in a wireless LAN
Publication Date: 2021.04.07 BRITISH TELECOM PLC
  • EP2979485B1 patent drawingFigure 1
  • EP2979485B1 patent drawingFigure 2
  • EP2979485B1 patent drawingFigure 3

AI summary

Embodiments of the invention provide a traffic control system for WLAN access points. The traffic control system works in dependence on a first input - user priority (supplied by an authentication server). This allows different service levels to be provided to different classes of customer. In addition the traffic control system polices and/or shapes traffic based on a second input - a modulation rate detector, which measures the modulation rate at which each connected client is sending its traffic, and uses it to indirectly cause fairer use of the available air interface capacity (e.g. by causing TCP streams to back off when they detect packet loss). Finally, for some embodiments where public Wi-Fi is being delivered through private Wi-Fi access points, the traffic control system is able to manage the air interface utilisation split between public and private Wi-Fi users, to ensure that private users do not have their Wi-Fi air interface network capacity unduly impaired by public users.