FTM-Based WLAN Steering for Faster, More Accurate Handover
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Solution Overview
Problem
Existing wireless local area network (WLAN) systems face challenges in seamless handover of client devices between access points due to delayed or missed steering opportunities caused by unresponsive stations and environmental interference, leading to suboptimal network performance and load balancing.
Innovation Solution
Implementing fine timing measurement (FTM) frames to determine the distance and location of stations within the WLAN, enabling faster and more accurate steering decisions based on real-time location awareness, and utilizing both FTM frames and signal strength for precise placement of range extenders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional steering methods are used based on signal strength alone, then the system is simple to implement, but steering decisions are delayed or missed due to unresponsive stations and environmental interference
Solution Approach 1:
The patent introduces FTM frames as an intermediary mechanism between the AP and STA to obtain accurate location information. Instead of relying solely on signal strength measurements which can be affected by environmental factors and STA responsiveness, the FTM frames provide a standardized measurement protocol that enables reliable distance measurement through round-trip time calculation, thus resolving the contradiction between steering speed and accuracy
Solution Approach 2:
The patent replaces the traditional signal strength-based steering mechanism with an FTM-based location measurement mechanism. This substitution transitions from indirect inference (signal strength to distance) to direct measurement (round-trip time to distance), improving both the speed and reliability of steering decisions by eliminating the ambiguities inherent in signal strength measurements
2Measurement precision
If FTM frames are used to determine station location, then steering accuracy is improved, but the device complexity increases due to additional frame exchange protocols
Solution Approach 1:
The patent leverages the existing FTM protocol framework which was originally designed for location services and applies it to steering decisions. This multi-functional use of FTM frames allows the system to achieve accurate location measurements while utilizing a standardized protocol that reduces implementation complexity compared to creating a custom measurement mechanism
Solution Approach 2:
The patent performs location measurements using FTM frames in advance of steering decisions. By proactively obtaining and caching location information, the system prepares measurement data before steering is needed, reducing the complexity of real-time decision-making and allowing for more从容 processing of steering logic
3Speed
If continuous monitoring of signal strength is performed, then steering responsiveness is improved, but energy consumption increases
Solution Approach 1:
The patent implements periodic FTM frame exchanges instead of continuous signal strength monitoring. By scheduling location measurements at appropriate intervals and triggering them based on specific conditions (such as signal strength thresholds or mobility detection), the system maintains steering responsiveness while significantly reducing energy consumption compared to continuous monitoring
Data Source
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AI summary
This disclosure provides methods, devices and systems for access point (AP) steering or frequency band steering based on a location of a station (STA). In some aspects, an AP may determine the location of the STA based on timing information and may steer the STA based on the location. To obtain the timing information, the AP may exchange fine timing measurement (FTM) frames with the STA. The AP may determine a distance between itself and the STA based on the timing information. The AP also may obtain distance information from other APs. Using the distance between itself and the STA, as well as the distance information from other APs, the AP may determine a location of the STA and steer the STA based on its location. The AP may steer the STA to a different frequency band of the same AP or to different AP altogether.