Spatial Orthogonal Channel Access for WLAN Fairness

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current WLAN channel access methods under spatial reuse fail to ensure fairness in channel access, leading to unfavorable conditions for stations without sectorization capabilities, affecting their data transmission effectiveness.

Innovation Solution

A channel access method where an intercepting station detects a first radio signal, updates its network allocation vector or response indication deferral, and triggers a channel contention procedure if a second radio signal meets spatial orthogonal conditions, allowing for data transmission within an updated duration, thereby ensuring fair access and spatial reuse.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If an intercepting station uses spatial orthogonal transmission to cancel NAV and initiate data transmission, then spatial reuse is achieved, but channel access fairness deteriorates for stations without sectorization capabilities

Engineering Contradiction:
Improvespatial reuse efficiencyVSAvoidchannel access fairness
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent applies local quality by differentiating channel access rules based on station capabilities. Stations with sectorization capabilities (AP2, STA3) are allowed to perform spatial orthogonal transmission and cancel NAV, while stations without such capabilities (STA4, STA5) follow traditional NAV-based access. This localized differentiation resolves the contradiction by allowing spatial reuse where applicable while maintaining fairness for legacy stations.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments the channel access mechanism into two parallel paths: one for stations with spatial orthogonal transmission capability and another for traditional stations. By dividing the access protocol into capability-based segments, the system achieves spatial reuse for advanced stations while preserving fair access for all stations, thus resolving the contradiction between productivity and ease of operation.

Inventive Principle:
Principle #1Segmentation

2Reliability

If stations wait for TXOP protection to end before contending for channel, then transmission collision is avoided, but channel access time increases

Engineering Contradiction:
Improvetransmission collision avoidanceVSAvoidchannel access delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by allowing stations to perform spatial orthogonal transmission checks before the NAV protection period ends. Stations like AP2 and STA3 can detect spatial orthogonality in advance and prepare for early channel contention, thus reducing access delay while maintaining collision avoidance through the spatial orthogonality verification mechanism.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces dynamics by making the channel access timing flexible rather than fixed. Instead of all stations waiting for NAV to expire, the system dynamically allows early contention for stations that verify spatial orthogonality. This dynamic adjustment resolves the contradiction by adapting access time based on spatial conditions, reducing delay while preserving reliability.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3007510B1Method for accessing channel under spatial multiplexing and station
Publication Date: 2020.02.12 ZTE CORP
  • EP3007510B1 patent drawingFigure 1
  • EP3007510B1 patent drawingFigure 2
  • EP3007510B1 patent drawingFigure 3

AI summary

Disclosed are a channel access method under spatial reuse and a station thereof, wherein, the method includes: an intercepting station detecting a first radio signal of a third-party station and updating a local network allocation vector and/or response indication deferral; triggering a channel contention access procedure when determining that a second radio signal of the third-party station meets a spatial orthogonal condition, and then completing data transmission within updated time. In the case that the network allocation vector or response indication deferral is not 0, the third-party station ignoring or resetting the network allocation vector or the response indication deferral when determining that a sector transmission in a transmission initiated by the station is orthogonal with a transmission space to be carried out by itself, the third-party station initiating a contention and starting the spatial orthogonal transmission within a duration indicated by the updated network allocation vector or the response indication deferral, so as to achieve the spatial reuse, ensure fairness of channel access between stations, and ensure the effectiveness of the stations' data transmission.