Coordinated Clear Channel Assessment for Wireless Repeaters

Solution Overview

Problem

Current wireless communication systems face inefficiencies in coordinated clear channel assessments (CCAs) when using repeaters in unlicensed bands, leading to increased latency and reduced data speeds due to sequential LBT procedures, which waste the channel occupancy time (COT) budget and delay communications.

Innovation Solution

Implementing coordinated CCAs where the initiating node and repeater perform CCAs during overlapping time periods, with control signals triggering simultaneous or offset CCAs, allowing for successful signal transmissions and initiating communications within the COT without interrupting each other's procedures, thus maintaining the COT budget and reducing delays.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sequential LBT procedures are performed by the initiating node and repeater, then channel access is achieved, but channel occupancy time is wasted and latency increases

Engineering Contradiction:

Improvechannel access reliabilityVSAvoidchannel occupancy time waste

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent merges the LBT procedures of the initiating node and repeater into a coordinated simultaneous execution. Both nodes perform their clear channel assessments at the same time based on a trigger signal, eliminating the sequential waiting period. This combining of previously separate procedures directly reduces the time waste while maintaining reliable channel access through coordinated confirmation signals.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent implements preliminary coordination through a trigger signal that prepares both the initiating node and repeater to perform LBT simultaneously. The trigger signal is sent in advance to synchronize the start of CCA operations, ensuring both nodes are ready to assess the channel at the same moment. This preliminary synchronization action prevents the time waste associated with sequential execution while ensuring reliable channel access.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If sequential LBT procedures are performed, then channel access is achieved, but data speed is reduced

Engineering Contradiction:

Improvechannel access reliabilityVSAvoiddata speed

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent merges the LBT procedures of the initiating node and repeater into a coordinated simultaneous execution. Both nodes perform their clear channel assessments at the same time based on a trigger signal, eliminating the sequential waiting period. This combining of previously separate procedures directly reduces the time waste while maintaining reliable channel access through coordinated confirmation signals.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent implements preliminary coordination through a trigger signal that prepares both the initiating node and repeater to perform LBT simultaneously. The trigger signal is sent in advance to synchronize the start of CCA operations, ensuring both nodes are ready to assess the channel at the same moment. This preliminary synchronization action prevents the time waste associated with sequential execution while ensuring reliable channel access.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If coordinated CCAs are performed during overlapping time periods, then COT budget is maintained and delays reduced, but system complexity increases

Engineering Contradiction:

Improvecommunication efficiencyVSAvoidcoordination mechanism complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent uses a trigger signal as an intermediary mechanism to coordinate the CCA operations between the initiating node and repeater. This single control signal simplifies the coordination complexity by providing a unified synchronization method rather than requiring complex bidirectional communication protocols. The intermediary trigger signal enables overlapping time period execution while keeping the coordination mechanism relatively simple and manageable.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12200766B2Coordinated clear channel assessment (CCA) for wireless repeaters

Publication Date: 2025.01.14 QUALCOMM INC

AI summary

Systems, devices, and methods for performing coordinated clear channel assessments (CCAs) in a shared radiofrequency band are provided. In one aspect, a method of wireless communication performed by a first wireless communication device includes: receiving a control signal indicating a CCA trigger associated with the first wireless communication device and a second wireless communication device; performing, based on the CCA trigger, a CCA; transmitting, to the second wireless communication device based on the CCA, a first CCA success signal; receiving, from the second wireless communication device, a second CCA success signal; initiating, based on the first CCA success signal and the second CCA success signal, a channel occupancy time (COT); and amplifying and forwarding a communication in the COT.