Filtering-Based Scanning for WLAN Link Setup Latency

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Solution Overview

Problem

Current wireless communication systems face challenges in minimizing link setup latency, especially when multiple users simultaneously attempt network access, leading to inefficiencies in the active scanning process.

Innovation Solution

The method involves transmitting a first frame with filtering information from a station (STA) to access points (APs), determining whether a second frame is transmitted based on this information, which includes received signal strength or charging type criteria, to optimize the link setup process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If all APs transmit probe response frames in active scanning, then network coverage is maximized, but traffic overload and link setup latency increase

Engineering Contradiction:
Improvenetwork coverageVSAvoidlink setup latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The STA performs preliminary filtering by evaluating APs against stored filter lists (containing SSID, BSSID, capability, or security information) before requesting probe responses. This preliminary action prevents unnecessary probe response transmissions from APs that do not match the STA's requirements, reducing traffic overload and link setup latency while maintaining reliable network coverage for matching APs.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Instead of all APs transmitting probe responses, only a partial subset of APs that match the filtering criteria transmit responses. This partial action reduces the total number of probe response frames in the network, directly addressing traffic overload and latency issues while ensuring that relevant APs maintain full responsiveness.

Inventive Principle:
Principle #16Partial or excessive action

2Productivity

If filtering criteria are applied to probe requests, then unnecessary probe responses are reduced, but device complexity increases

Engineering Contradiction:
Improvescanning efficiencyVSAvoidfiltering mechanism complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The filter list structure is designed to be universal and multi-functional, supporting multiple types of filtering criteria (SSID, BSSID, capability information, security information) within a single data structure. This universality allows the STA to perform various filtering operations without requiring separate mechanisms for each criterion, thereby improving scanning efficiency while minimizing the increase in device complexity.

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

Solution Approach 2:

The filtering mechanism uses copied and stored filter lists containing AP information (SSID, BSSID, capability, security) that are maintained in the STA's memory. Instead of performing complex real-time analysis, the STA compares incoming probe requests against these pre-copied filter lists, simplifying the filtering process while maintaining high scanning efficiency.

Inventive Principle:
Principle #26Copying

3Speed

If the STA requests probe responses from multiple APs simultaneously, then link setup speed is improved, but traffic overload increases

Engineering Contradiction:
Improvelink setup speedVSAvoidtraffic volume
Core Design Contradiction:
SpeedVSQuantity of substance

Solution Approach 1:

The STA performs preliminary filtering of APs using stored filter lists before transmitting probe requests. This preliminary action ensures that probe requests are only sent to APs that match the STA's requirements, thereby maintaining fast link setup speed through targeted requests while reducing the total quantity of probe response traffic in the network.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The filtering process applies local quality control by evaluating each AP individually against the filter criteria. This allows the STA to selectively request probe responses from specific APs that match local requirements (such as SSID, capability, or security criteria), improving link setup speed for relevant APs while reducing overall traffic volume by excluding non-matching APs.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2830362B1Method and apparatus for filtering-based scanning in WLAN system
Publication Date: 2018.07.18 LG ELECTRONICS INC
  • EP2830362B1 patent drawingFigure 1
  • EP2830362B1 patent drawingFigure 2
  • EP2830362B1 patent drawingFigure 3

AI summary

Abstract: The present invention relates to a wireless communication system, and more specifically, disclosed are a method and an apparatus for filtering-based scanning in a WLAN system. A method for a station (STA) setting up a high-speed link in the wireless communication system, according to one embodiment of the present invention, comprises the steps of: transmitting a first frame comprising filtering information to at least one access point (AP); and receiving a second frame from a portion or all of the at least one AP, wherein whether to transmit the second frame can be determined on the basis of the filtering information.