Wireless Transmission Start Time Selection for Collision Avoidance

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Solution Overview

Problem

In wireless communication systems operating in shared frequency bands, such as unlicensed bands, transmission collisions occur due to limited start time positions, leading to inefficiencies and interference, despite the use of Listen-before-talk (LBT) mechanisms for channel access.

Innovation Solution

A method and apparatus that determine collision probability with neighboring transmitters and dynamically select start time positions for burst transmissions based on this probability, using a network device with collision determination, selection, and reselection units to minimize collisions and improve spectrum efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If LBT mechanism is used for channel access, then fair coexistence in unlicensed band is improved, but transmission collisions still occur due to limited start time positions

Engineering Contradiction:
Improvefair coexistenceVSAvoidtransmission efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent makes the start time position dynamic by allowing flexible selection from multiple candidate positions (first, second, third start time positions) rather than using a fixed position. The system dynamically adjusts which candidate position to use based on channel conditions and LBT outcomes, resolving the contradiction between fair coexistence and transmission efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of start time position from a fixed value to a selectable set of candidate positions. By modifying this temporal parameter and allowing flexible selection among multiple options, the system achieves both fair coexistence through LBT and improved transmission efficiency by avoiding collisions.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If fixed start time position is used for transmissions, then device complexity is reduced, but transmission collisions increase

Engineering Contradiction:
Improvescheduling complexityVSAvoidresource efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent segments the start time position into multiple candidate positions (first, second, third start time positions) distributed across different time instances. This segmentation allows the system to select from multiple options rather than using a single fixed position, reducing collisions while maintaining manageable complexity through structured candidate selection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from a static fixed start time position to a dynamic selection mechanism that chooses from multiple candidate positions. This dynamic approach improves resource efficiency by adapting to channel conditions while keeping device complexity reasonable through predefined candidate sets.

Inventive Principle:
Principle #15Dynamics

3Productivity

If multiple candidate start time positions are introduced, then transmission collisions are reduced, but device complexity increases

Engineering Contradiction:
Improvetransmission efficiencyVSAvoidscheduling complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent modifies the start time position parameter from a single fixed value to a set of candidate positions with different time offsets. This parameter change reduces transmission collisions by providing multiple temporal opportunities while managing complexity through structured parameter definition and selection rules.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3479620B1Method and apparatus for controlling transmission in wireless communication system
Publication Date: 2021.02.24 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3479620B1 patent drawingFigure 1~2b
  • EP3479620B1 patent drawingFigure 3a~4a
  • EP3479620B1 patent drawingFigure 4b~6a

AI summary

Embodiments of the present disclosure provide methods, apparatuses and computer program for controlling transmission in a wireless communication system. The method implemented at a network device comprises: determining a collision probability with one or more neighboring transmitter; and selecting a start time position for a plurality of burst transmissions related to the network device based on a result of the determination. By virtue of the method, collision of transmissions from neighboring transmitters can be reduced, and spectrum efficiency of the wireless communication system may be improved.