Cross-Channel Channel Reservation Indication for Interference Mitigation

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Solution Overview

Problem

In wireless communication systems, the existing channel reservation methods using Clear Channel Assessment (CCA) and Channel Usage Beacon Signals (CUBS) are inadequate as they may not be detectable by all nodes, leading to interference, especially when nodes operating with different radio access technologies contend for access to a shared radio frequency spectrum.

Innovation Solution

A method where a first node transmits a channel reservation indication that can be understood by a second node operating with a different radio access technology, on either the intended channel or adjacent/overlapping channels, to effectively reserve the channel and mitigate interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a node transmits a CUBS to reserve a channel, then the channel reservation is effective for nodes with sensitive energy detection circuits, but nodes with less sensitive energy detection circuits may not detect the CUBS and can transmit interfering signals

Engineering Contradiction:
Improvechannel reservation effectivenessVSAvoidinterference from undetected nodes
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a channel reservation indication as an intermediary signal that bridges the gap between CUBS transmission and node detection. This indication is transmitted on a different channel (second channel) than the one being reserved (first channel), allowing nodes to detect the reservation status through an alternative signaling path that is more reliably received than the CUBS energy detection method

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent moves the reservation signaling from the frequency domain (energy detection on the same channel) to a cross-channel dimension. By transmitting the channel reservation indication on a second channel while reserving the first channel, the system creates a new dimensional approach to channel reservation that bypasses the limitations of energy detection sensitivity

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If a node transmits a channel reservation indication on the intended channel, then the reservation is clear for that channel, but nodes monitoring other channels may not receive the indication

Engineering Contradiction:
Improvechannel reservation detection accuracyVSAvoidcross-channel reservation recognition
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent implements cross-channel signaling by transmitting the channel reservation indication on a second channel while reserving the first channel. This dimensional shift allows nodes monitoring the second channel to receive the reservation indication, thereby achieving both precise reservation detection and broad cross-channel adaptability

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Productivity

If nodes operate with different radio access technologies on a shared spectrum, then spectrum utilization is enhanced, but interference scenarios increase due to different detection sensitivities

Engineering Contradiction:
Improvedata transmission capacityVSAvoidinterference between different radio access technologies
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent creates a universal channel reservation mechanism that works across different radio access technologies. The channel reservation indication serves multiple functions: it reserves the first channel for the transmitting node, provides detectable signaling for nodes with less sensitive energy detection circuits, and operates on a second channel to ensure broad monitoring coverage. This multi-functional approach enables different RATs to coexist on shared spectrum with reduced interference

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

Solution Approach 2:

The channel reservation indication acts as a mediator between different radio access technologies with different detection capabilities. Rather than relying on technology-specific detection mechanisms, the patent introduces this intermediary signal that can be reliably detected by various node types, thereby enabling interoperability and reducing interference between different RATs

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3235327B1Techniques for reserving a channel of a radio frequency spectrum
Publication Date: 2020.09.16 QUALCOMM INC
  • EP3235327B1 patent drawingFigure 1
  • EP3235327B1 patent drawingFigure 2
  • EP3235327B1 patent drawingFigure 3

AI summary

Techniques are described for wireless communication. A first method includes contending for access to a first channel of a radio frequency spectrum, and transmitting, upon winning contention for access to the first channel, a first channel reservation indication. The contending may be performed by a first node operating according to a first radio access technology. The first channel reservation indication may be understood by a second node operating according to a second radio access technology.