Parallel WLAN Channel Access for Mixed-Bandwidth STAs

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Solution Overview

Problem

In WLAN systems with multiple channel widths, the available frequency bandwidth is underutilized due to the limitations of STAs that can only transmit and receive on a small fraction of the available bandwidth, leading to resource wastage and congestion, especially in systems like 802.11ah and 802.11af that operate on sub-1 GHz bands.

Innovation Solution

Implementing multi-user parallel channel access (MU-PCA) and single-user parallel channel access (SU-PCA) using transmit and/or receive with symmetrical or asymmetrical bandwidth, along with MAC and PHY layer designs to enable simultaneous transmissions and receptions across multiple channels, allowing STAs with different operating capabilities to utilize the entire available bandwidth efficiently.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the primary channel bandwidth is limited by the STA with the smallest operating bandwidth to ensure compatibility, then all STAs can communicate successfully, but the available frequency bandwidth is underutilized and resource wastage occurs

Engineering Contradiction:

Improvecompatibility across different STA capabilitiesVSAvoidfrequency bandwidth utilization

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The available frequency bandwidth is divided into multiple channels of different widths. STAs are assigned to channels matching their operating capabilities, allowing simultaneous communication on multiple channels rather than forcing all STAs to use a single narrow primary channel.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system transitions from single-channel sequential access to multi-channel parallel access, adding a frequency dimension to channel allocation. This allows multiple STAs to communicate simultaneously on different frequency channels, fully utilizing the available bandwidth.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If only one STA transmits at any given time using CSMA/CA to avoid collisions, then transmission reliability is maintained, but system throughput is limited and congestion occurs

Engineering Contradiction:

Improvecollision-free transmissionVSAvoidsystem throughput

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The system segments the single transmission channel into multiple parallel channels, allowing multiple STAs to transmit simultaneously without collisions on each channel, thereby increasing overall throughput while maintaining reliability through dedicated channel allocation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple channel access mechanisms are merged: CSMA/CA is used on the primary channel for control frames, while data transmission occurs in parallel on multiple channels with dedicated allocations, combining the reliability of collision avoidance with the throughput of parallel access.

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If the system supports STAs with different operating bandwidths (1 MHz to 16 MHz) to increase adaptability, then more device types can connect, but the primary channel must be limited to the smallest bandwidth causing resource wastage

Engineering Contradiction:

Improvesupport for multiple STA capabilitiesVSAvoidavailable frequency bandwidth

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

Different channels are allocated with different bandwidth qualities matching the specific capabilities of each STA. STAs with higher capabilities are assigned wider channels, while STAs with lower capabilities use narrower channels, ensuring each STA operates at its optimal performance level without limiting others.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The system creates a universal channel allocation framework that can accommodate STAs with various bandwidth capabilities (1, 2, 4, 8, 16 MHz) simultaneously. The primary channel serves as a universal control interface, while additional channels provide enhanced bandwidth for capable STAs.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP4730898A1Multi-user parallel channel access in WLAN systems

Publication Date: 2026.04.22 INTERDIGITAL PATENT HOLDINGS INC

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AI summary

A method and apparatus may provide multi-user parallel channel access (MU-PCA) and/or single-user parallel channel access (SU-PCA) using transmit and/or receive with symmetrical bandwidth, in the downlink (DL), uplink (UL), or combined DL and UL. SU-PCA and MU-PCA may support unequal modulation and coding schemes (MCS) and unequal transmit power. Medium access control (MAC) layer, Physical layer (PHY), and mixed and PHY layer methods and procedures may support UL, DL and combined UL and DL SU-PCA and MU-PCA using transmit and/or receive with symmetrical bandwidth. MU-PCA and/or SU-PCA may also be supported by MAC and PHY layer designs and procedures for downlink, uplink and combined uplink and downlink using transmit/receive with asymmetrical bandwidth.