Clear-to-Send Duration Field Adjustments for Wireless Interference

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Solution Overview

Problem

In wireless local area networks (WLANs), especially those operating under different IEEE 802.11 standards, there is a challenge in efficiently managing the duration field of Clear-to-Send (CTS) frames to accommodate devices operating with varying protocols and hardware bandwidth, leading to potential interference and resource inefficiencies, particularly when coexisting with legacy devices and other wireless technologies like Bluetooth.

Innovation Solution

The proposed solution involves adjusting the duration field of CTS frames to account for interference and coexistence with other wireless technologies by modifying the duration setting in CTS frames based on the specific conditions, such as scheduled transmissions from other devices, ensuring that devices can complete receptions without failure due to overlapping signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the duration field of CTS frames is set to accommodate legacy devices and devices with varying hardware bandwidth, then compatibility and ease of operation are improved, but interference and resource inefficiency increase

Engineering Contradiction:
ImprovecompatibilityVSAvoidinterference
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent applies dynamics by making the CTS duration field adjustable rather than fixed. The system dynamically modifies the duration field value based on the specific transmission conditions, device capabilities, and network environment. This allows the CTS frame to adapt its duration to match actual transmission needs, preventing both excessive duration (which causes interference) and insufficient duration (which causes transmission failures).

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent directly changes the parameter of the duration field in CTS frames. By modifying this specific parameter based on transmission conditions, device type, and bandwidth capabilities, the system optimizes the balance between compatibility and interference reduction. The duration field is adjusted to precise values that accommodate legacy devices while minimizing unnecessary channel occupation.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the duration field of CTS frames is extended to ensure complete reception for all devices, then reliability is improved, but resource utilization and network efficiency deteriorate

Engineering Contradiction:
Improvereception completenessVSAvoidnetwork efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies partial action by setting the CTS duration field to exactly the minimum necessary value required for complete reception, rather than using a fixed excessive duration. The system calculates the precise duration needed based on the specific transmission parameters and device capabilities, providing just enough time for reliable reception without extending beyond what is necessary. This prevents unnecessary channel occupation while ensuring all devices can complete their reception.

Inventive Principle:
Principle #16Partial or excessive action

3Device complexity

If CTS frames use fixed duration settings according to standard protocols, then device complexity is reduced, but adaptability to different protocols and hardware bandwidth deteriorates

Engineering Contradiction:
Improveprotocol simplicityVSAvoidprotocol compatibility
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent changes the duration field parameter of CTS frames based on the specific protocol version and device capabilities detected in the network. The system identifies whether legacy devices or modern devices are present and adjusts the duration field accordingly, enabling a single system to operate effectively across multiple protocol versions and hardware configurations without requiring separate fixed settings for each case.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4426053A1Clear-to-send duration field adjustments
Publication Date: 2024.09.04 INTEL CORP
  • EP4426053A1 patent drawingFigure 1~2
  • EP4426053A1 patent drawingFigure 3~4
  • EP4426053A1 patent drawingFigure 5

AI summary

Methods, apparatuses, and computer readable media for clear-to-send duration field adjustments are disclosed. Apparatuses of a station (STA) are disclosed, where the apparatuses comprise processing circuitry configured to: decode a physical layer protocol data unit (PPDU), the PPDU including a request to send (RTS) frame, the RTS frame comprising an address of the STA and a first duration field, the first duration field indicating a first duration. The processing circuitry is further configured to: setting a second duration to a duration that ends before a transmission and encoding for transmission a clear-to-send (CTS) frame, the CTS frame comprising a second duration field, the second duration field indicating the reduced second duration.