Prioritized Spectrum Access via Dynamic Preemption

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Solution Overview

Problem

In wireless communication systems, shared or unlicensed spectrum usage often results in collisions between transmissions from different operators, disrupting prioritized communications due to the lack of effective medium access control mechanisms.

Innovation Solution

Implementing a prioritization scheme that allows devices associated with prioritized operators to access shared frequency bands over non-prioritized devices, using clear channel assessment (CCA) and medium preemption opportunities to ensure prioritized operators gain access instantly while non-prioritized operators yield control when necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a prioritization scheme is implemented to allow prioritized operators to access shared spectrum immediately, then access speed and reliability for prioritized operators is improved, but non-prioritized operators experience increased access delays and spectrum underutilization

Engineering Contradiction:

Improveaccess reliability for prioritized operatorsVSAvoidaccess delay for non-prioritized operators

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system dynamically switches between two access modes: Listen-Before-Talk (LBT) for non-prioritized operators and immediate access for prioritized operators. The base station can dynamically allocate preemption opportunities and adjust the behavior of different operators based on current channel conditions and traffic requirements, resolving the contradiction between immediate access for prioritized operators and fair access for non-prioritized operators

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the access parameter (access delay) based on operator priority status. Prioritized operators are granted immediate access (zero delay) while non-prioritized operators use LBT with configurable delays. The base station can adjust the LBT parameters and preemption opportunity timing to optimize both access speed and spectrum utilization

Inventive Principle:

Principle #35Parameter changes

2Productivity

If non-prioritized operators continuously transmit to maximize spectrum utilization, then spectrum efficiency is improved, but collisions with prioritized operator transmissions increase

Engineering Contradiction:

Improvespectrum utilization efficiencyVSAvoidtransmission collisions

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The system performs preliminary actions by scheduling preemption opportunities before prioritized operator transmissions. The base station informs non-prioritized operators in advance about upcoming preemption opportunities, allowing them to pause transmissions proactively. This prevents collisions before they occur while maintaining high spectrum utilization during non-preemption periods

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The base station provides feedback to non-prioritized operators about channel status and preemption opportunities. This feedback mechanism allows non-prioritized operators to adjust their transmission behavior dynamically, pausing when preemption is detected and resuming when the channel is clear, thereby maximizing spectrum utilization while avoiding collisions with prioritized transmissions

Inventive Principle:

Principle #23Feedback

3Object-generated harmful factors

If LBT procedure is used by non-prioritized operators to detect prioritized transmissions, then collision avoidance is improved, but access latency increases

Engineering Contradiction:

Improvecollision avoidanceVSAvoidaccess latency for non-prioritized operators

Core Design Contradiction:

Object-generated harmful factorsVSLoss of time

Solution Approach 1:

The system implements periodic preemption opportunities at predetermined intervals instead of continuous LBT monitoring. Non-prioritized operators only need to pause and listen at these periodic intervals, significantly reducing the time spent on channel sensing while still effectively avoiding collisions with prioritized transmissions. This periodic approach maintains collision avoidance while minimizing access latency

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS11297510B2Medium access for shared or unlicensed spectrum

Publication Date: 2022.04.05 QUALCOMM INC

AI summary

Methods, systems, and devices are described for wireless communication at a UE. A wireless devices may use a shared or unlicensed spectrum configuration based on a prioritization scheme for the shared frequency resources. The prioritization scheme may assign a priority to different operators and may enable devices associated with a prioritized operator to access the shared band over non-prioritized devices. For example, a non-prioritized device may win the channel and begin communicating over the shared or unlicensed spectrum. The non-prioritized device may then periodically cease transmission for a set interval (i.e., a preemption opportunity) and listen for an indication that a prioritized device wishes to use the channel. If a prioritized device begins transmitting (or, in some cases, if the prioritized device transmits a medium preemption indication) the non-prioritized device may relinquish control of the channel.