Channel Transfer Frames for Inter-AP Sounding Coordination

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Solution Overview

Problem

Existing wireless communication systems face challenges in performing channel sounding across multiple access points (APs) to prevent interference and enhance data transmission rates, particularly in intra-frequency deployments where APs share the same frequency band, leading to potential interference and limited network throughput.

Innovation Solution

A method and apparatus for channel sounding across APs, involving the use of channel transfer command frames and sounding dialog tokens to identify and forward channel sounding results accurately between APs, allowing concurrent data transmission without interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If multiple APs are deployed on the same frequency to improve network coverage and capacity, then network coverage and capacity are improved, but interference between APs occurs and data transmission reliability deteriorates

Engineering Contradiction:
Improvenetwork coverageVSAvoiddata transmission reliability
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent performs channel sounding before data transmission to obtain channel state information in advance. The controller AP initiates channel sounding procedures where member APs measure channels to STAs, and results are transferred across APs before actual data transmission occurs, enabling proactive interference management

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where channel sounding results are measured and reported back to the controller AP, which then uses this information to coordinate transmissions. The channel state information feedback enables the system to adjust transmissions based on actual channel conditions, preventing interference

Inventive Principle:
Principle #23Feedback

2Productivity

If multiple APs transmit data concurrently to improve network throughput, then data transmission rate is improved, but interference between APs and STAs occurs

Engineering Contradiction:
Improvenetwork throughputVSAvoidinterference
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent performs channel sounding and obtains channel state information before allowing concurrent transmissions. The controller AP coordinates this preliminary channel measurement phase, ensuring that all necessary channel information is available before APs begin simultaneous data transmission, thus enabling interference-free concurrent operations

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses channel sounding feedback to determine which APs can transmit concurrently. The measured channel state information is fed back to the controller, which uses this information to make coordinated transmission decisions, allowing multiple APs to transmit simultaneously only when channel conditions permit without causing interference

Inventive Principle:
Principle #23Feedback

3Productivity

If channel sounding is performed across APs to enable interference nulling mode, then data transmission rate is improved, but system complexity increases due to lack of existing solutions

Engineering Contradiction:
Improvedata transmission rateVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent introduces a controller AP as an intermediary that coordinates channel sounding across multiple member APs. The controller AP receives channel sounding results from member APs, transfers necessary information between APs, and manages the overall channel sounding process, thereby reducing the complexity burden on individual APs while enabling cross-AP channel knowledge

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the channel sounding process into distinct phases and responsibilities: member APs perform local channel measurements to their associated STAs, the controller AP coordinates the process and manages information transfer between APs. This segmentation allows complex cross-AP channel sounding to be broken down into manageable tasks distributed across multiple APs

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4145865B1Channel measurement method and communication device
Publication Date: 2025.10.22 HUAWEI TECH CO LTD
  • EP4145865B1 patent drawingFigure 1~2
  • EP4145865B1 patent drawingFigure 3~4
  • EP4145865B1 patent drawingFigure 5

AI summary

This application discloses a channel sounding method and a communication apparatus. The method includes: A first access point receives a channel transfer command frame from a controller or a central access point, and sends a channel transfer frame to a second access point based on the channel transfer command frame. The channel transfer command frame indicates the first access point to send a channel sounding result of at least one station to the second access point. The channel transfer command frame includes a first sounding dialog token number. The channel transfer frame carries a channel sounding result corresponding to a first sounding dialog token in channel sounding results of a plurality of stations. In the method, the at least one station is associated with the first access point. After receiving the channel transfer command frame, the first access point forwards the channel sounding result of the at least one station to the second access point. In this way, channel sounding is performed across access points, so that a plurality of intra-frequency deployed access points can concurrently send data, and a data transmission rate in an entire wireless network is improved.