Off-Channel WiFi Probe Frame Injection for Device Detection

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Solution Overview

Problem

Current WiFi networks are limited in communicating with devices operating on different frequency channels, preventing the gathering of radio information from off-channel wireless devices, which is essential for managing network performance and handling increasing multimedia and IoT traffic.

Innovation Solution

The method involves generating and injecting frames from one frequency channel to another to gather radio information from off-channel devices by using a transceiver system to transmit and receive frames, and processing systems to identify and store the information from the received frames, allowing for the identification of devices operating on different channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If WiFi networks operate on dedicated frequency channels to prevent interference, then network reliability is improved, but the ability to gather information from off-channel devices is lost

Engineering Contradiction:
Improvenetwork reliabilityVSAvoidradio information from off-channel devices
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The system periodically switches the transceiver between operating channel and target channel to inject probe frames and collect responses, enabling periodic information gathering from off-channel devices without permanently leaving the operating channel

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent uses frame injection as an intermediary mechanism to communicate with off-channel devices. By injecting specially formatted probe frames on the target channel and capturing responses, the system indirectly gathers information from devices on different channels while maintaining channel separation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If devices are restricted to their assigned collision domains and channels, then network stability is improved, but network intelligence and management capability deteriorates

Engineering Contradiction:
Improvenetwork stabilityVSAvoidnetwork intelligence
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The system dynamically switches channels to gather information from off-channel devices while maintaining stable operation on the primary channel. The transceiver can adaptively move between channels based on information gathering needs without disrupting normal network operations

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system performs preliminary channel switching and frame injection actions before needing information about off-channel devices. By proactively gathering radio information about neighboring channels and devices, the network gains advance intelligence for better management decisions

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the transceiver remains on the current frequency channel, then communication efficiency is improved, but the ability to probe off-channel devices is lost

Engineering Contradiction:
Improvecommunication efficiencyVSAvoidoff-channel device detection
Core Design Contradiction:
ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

The transceiver periodically switches to target channels to inject probe frames and collect responses, then returns to the operating channel. This periodic off-channel probing enables device detection while minimizing impact on communication efficiency

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system creates copies of probe frames and injects them on target channels without affecting the primary communication channel. By using frame copying and injection techniques, the system can detect off-channel devices while maintaining normal communication operations

Inventive Principle:
Principle #26Copying

Data Source

PatentEP3614705B1Method and system to collect information from off-channel devices
Publication Date: 2020.07.29 AOIFE SOLUTIONS
  • EP3614705B1 patent drawingFigure 1
  • EP3614705B1 patent drawingFigure 2
  • EP3614705B1 patent drawingFigure 3

AI summary

The present invention introduces a novel method for gathering radio information about one or more user's terminals tuned to a specific frequency channel, from an access point/wireless router tuned to different channel, as long as they all support the IEEE 802.11 standard (WiFi). It makes use of a frame injection mechanism originally developed to enable communication in mesh (peer to peer) networks. The transmitter is able to identify the response from the receiver by building a specific MAC address in the management frames that it sends, so the acknowledgment from the receiver is identified without ambiguity. This probing protocol is designed to obtain useful insights from the received frame about the radio resources (signal strength, noise level, frequency, etc), so the target device information can be stored in an updated database for posterior processing.