Channel Availability Protocol Shared Spectrum

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Solution Overview

Problem

Current wireless communication systems in shared spectra face inefficiencies in determining channel availability, particularly with energy-detection and hand-shaking reservation techniques being costly and resource-intensive.

Innovation Solution

A channel availability protocol that identifies an initial contention window, transmits a request message after the window expires, measures signal quality, and initiates data transmission based on signal quality thresholds, with subsequent adjustments to contention window sizes based on response quality, independent of energy detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If energy-detection or hand-shake reservation procedures are used to determine channel availability, then channel access reliability is improved, but implementation cost and resource consumption increase

Engineering Contradiction:
Improvechannel access reliabilityVSAvoidimplementation cost
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the essential function of channel availability determination from complex energy-detection and hand-shake procedures. By using a simplified protocol where the receiving device autonomously measures signal quality and determines whether to respond based on predefined thresholds, the invention removes unnecessary complexity while preserving reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The receiving device performs self-service by autonomously measuring signal quality of the transmitted signal and independently deciding whether to send a response based on signal quality thresholds. This eliminates the need for complex coordination protocols and reduces implementation complexity while maintaining reliable channel access determination.

Inventive Principle:
Principle #25Self-service

2Reliability

If traditional channel availability protocols are implemented, then communication reliability is improved, but resource usage increases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidresource usage
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

Instead of requiring complete hand-shake procedures or continuous energy detection, the invention uses partial action by measuring signal quality only at specific points (when a transmitted signal is received) and making binary decisions based on thresholds. This reduces resource consumption while maintaining sufficient reliability for channel access determination.

Inventive Principle:
Principle #16Partial or excessive action

3Device complexity

If signal quality measurement is performed independently of energy detection, then implementation complexity is reduced, but measurement precision may be affected

Engineering Contradiction:
Improveimplementation complexityVSAvoidsignal quality measurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The invention changes the measurement parameter from general energy detection to specific signal quality metrics (such as SINR - Signal to Interference plus Noise Ratio). By measuring actual signal quality rather than just presence of energy, the system achieves better precision for determining whether the channel is suitable for communication, while keeping implementation simple through threshold-based decision making.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3721672B1Channel availability protocol in a shared spectrum
Publication Date: 2024.07.10 QUALCOMM INC
  • EP3721672B1 patent drawingFigure 1
  • EP3721672B1 patent drawingFigure 2
  • EP3721672B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communications are described. A transmitter may identify a contention window for a no-energy-detection protocol for determining a channel availability for a data transmission. After the contention window expires, the transmitter may send a request message to a receiver. The receiver may measure a quality of the request message against a request threshold and transmit a response message if the measured quality exceeds the request threshold. The transmitter may then measure a quality of the response message against a response threshold. If the measured quality exceeds the response threshold, the transmitter may initiate a data transmission with the receiver. If the quality falls below the response threshold or the response message is not received, the transmitter may adjust the contention window and reattempt the no-energy-detection protocol. The contention window may also be adjusted based on an acknowledgement message received after the data transmission.