Re-contention Gaps for Wireless Resource Scheduling

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Solution Overview

Problem

In wireless communication systems, particularly in shared communication mediums like unlicensed frequency bands, there is a challenge of inter-access terminal blocking due to contention schemes, which leads to inefficient resource utilization and potential interference between different Radio Access Technologies (RATs) such as LTE and Wi-Fi, especially with the increasing deployment of small cell access points.

Innovation Solution

The implementation of re-contention gaps and hierarchical scheduling grant schemes allows multiple access terminals to operate concurrently on orthogonal frequency resources or overlapping time and frequency resources, with prioritization and advanced scheduling techniques to mitigate blocking and enhance proportional fairness, thereby improving resource utilization and reducing interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple access terminals operate concurrently on shared communication medium using contention schemes, then resource utilization increases, but inter-access terminal blocking and interference occur

Engineering Contradiction:
Improveresource utilizationVSAvoidblocking and interference
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the shared communication medium into orthogonal frequency resources, allowing multiple access terminals to operate simultaneously on different frequency channels. This segmentation eliminates inter-terminal blocking by providing dedicated frequency resources while maintaining high resource utilization through concurrent operations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces frequency dimension separation to resolve time-domain contention conflicts. By allocating terminals to different frequency resources rather than relying solely on time-based contention schemes, the system achieves higher productivity without the blocking issues inherent in traditional contention-based access.

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

2Productivity

If small cell access points are deployed to improve coverage and capacity, then user experience and spectral efficiency improve, but interference with other RATs on unlicensed bands increases

Engineering Contradiction:
Improvespectral efficiencyVSAvoidinterference with other RATs
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the unlicensed spectrum into orthogonal frequency resources specifically allocated to LTE small cells, separating them from Wi-Fi and other RAT operations. This frequency segmentation allows small cells to achieve high spectral efficiency while minimizing harmful interference to other wireless systems sharing the unlicensed band.

Inventive Principle:
Principle #1Segmentation

3Reliability

If hierarchical scheduling grant schemes are implemented to prioritize access terminals, then blocking is reduced, but scheduling complexity increases

Engineering Contradiction:
Improveblocking reductionVSAvoidscheduling complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements preliminary scheduling actions by assigning orthogonal frequency resources to access terminals in advance through hierarchical scheduling grants. This preliminary allocation reduces blocking by pre-establishing conflict-free resource assignments, while the structured hierarchical approach manages scheduling complexity through systematic resource distribution rules.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3345450B1Inter-access terminal unblocking and enhanced contention for co-existence on a shared communication medium
Publication Date: 2021.03.31 QUALCOMM INC
  • EP3345450B1 patent drawingFigure 1
  • EP3345450B1 patent drawingFigure 2
  • EP3345450B1 patent drawingFigure 3

AI summary

Techniques for managing access to a shared communication medium are disclosed. Scheduling grants may be sent to different access terminals for different sets of resources for uplink transmission on the communication medium. A series of re-contention gaps may be scheduled for access terminal contention within or between the different sets of resources. Uplink and downlink transmission on the communication medium may be silenced during each of the series of re-contention gaps. Moreover, an access terminal may receive a scheduling grant that allocates a set of resources to the access terminal for uplink transmission on a communication medium and contend for access to the communication medium based on the scheduling grant. The access terminal may then selectively transmit uplink traffic over the allocated set of resources based on the contending.