Dynamic Contention Window for Fair Group COT Sharing

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Solution Overview

Problem

In wireless communication systems, particularly in 5G and LTE networks, the contention window adjustment for group channel occupancy time (COT) sharing is not effectively managed, leading to unfair channel access time among different groups of user equipment (UEs), resulting in inefficiencies and delays, especially in dense deployment scenarios with heavy-loaded or bursty traffic.

Innovation Solution

The implementation of an adjusted contention window size for the listen-before-talk (LBT) procedure, which allows UEs to determine an optimal window size based on factors such as the number of UEs in a group, RF coverage area, and shareable time-frequency resources, ensuring fair channel access time among different groups of UEs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a fixed contention window size is used for LBT procedure, then the LBT procedure is simple to implement, but channel access time fairness deteriorates among different groups of UEs

Engineering Contradiction:

Improvesimplicity of LBT procedureVSAvoidchannel access time fairness

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The contention window size is made dynamic rather than fixed. The base station adjusts the contention window size adaptively based on the number of UEs in each group, allowing the LBT procedure to respond to changing channel conditions and UE densities, thereby improving channel access fairness while maintaining implementation feasibility through centralized control

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The contention window size parameter is changed based on the number of UEs in each group. The base station calculates an appropriate contention window size for each group and communicates it to the UEs, allowing different groups to have different contention window sizes that reflect their actual channel access needs, thus resolving the fairness issue

Inventive Principle:

Principle #35Parameter changes

2Loss of time

If contention window size is adjusted for each group, then channel access time fairness is improved, but system complexity increases

Engineering Contradiction:

Improvechannel access time fairnessVSAvoidcontention window management complexity

Core Design Contradiction:

Loss of timeVSDevice complexity

Solution Approach 1:

The system segments UEs into different groups based on their service requirements and channel access patterns. Each group is assigned a specific contention window size tailored to its characteristics. This segmentation allows the base station to manage contention window sizes in a organized manner, reducing the overall complexity compared to managing individual UE parameters

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The base station acts as an intermediary that centralizes the contention window size management. Instead of each UE independently determining its contention window size (which would be complex), the base station calculates and assigns appropriate sizes to each group, simplifying the implementation while achieving fairness goals

Inventive Principle:

Principle #24Intermediary (Mediator)

3Loss of time

If larger contention window size is used, then channel access fairness is improved, but channel access efficiency deteriorates

Engineering Contradiction:

Improvechannel access fairnessVSAvoidchannel access efficiency

Core Design Contradiction:

Loss of timeVSProductivity

Solution Approach 1:

The contention window size parameter is dynamically adjusted based on the number of UEs in each group. Groups with more UEs are assigned larger contention window sizes to ensure fairness, while groups with fewer UEs use smaller sizes to maintain efficiency. This adaptive parameter change resolves the trade-off between fairness and efficiency

Inventive Principle:

Principle #35Parameter changes

4Productivity

If smaller contention window size is used, then channel access efficiency is improved, but channel access fairness deteriorates

Engineering Contradiction:

Improvechannel access efficiencyVSAvoidchannel access fairness

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The contention window size is made dynamic and adaptive to the specific group characteristics. Rather than using a uniformly small contention window size that would compromise fairness, the system dynamically adjusts sizes based on group density and service requirements, allowing efficiency to be maintained where appropriate while ensuring fairness where needed

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS11582800B2Contention window adjustment for group channel occupancy time sharing

Publication Date: 2023.02.14 QUALCOMM INC

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may determine an adjusted contention window size for a listen-before-talk (LBT) procedure that increases channel access time fairness between a plurality of different groups of UEs. The UE may determine, via the LBT procedure, that a channel is idle based at least in part on the adjusted contention window size. The UE may transmit, to other UEs in a group of UEs that includes the UE, control information that enables a group channel occupancy time (COT) associated with the channel to be shared with the other UEs in the group of UEs. Numerous other aspects are described.