Contention-Based Uplink OFDMA Resource Allocation

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Solution Overview

Problem

Current WLAN networks face inefficiencies in enabling multiple users to share the same wideband channel for uplink OFDMA operations, as existing methods require access points to collect traffic requests and manage resources, which can lead to suboptimal resource utilization.

Innovation Solution

Implementing a contention-based uplink OFDMA transmission method where access points reserve both dedicated and contention resources, allowing wireless communications devices to contend for access based on a random access probability scheme, eliminating the need for traffic request collection and simplifying resource arrangement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the AP collects traffic requests from STAs and manages resources for uplink OFDMA transmission, then resource allocation can be controlled and optimized, but the system complexity and management overhead increase

Engineering Contradiction:

Improveresource utilization efficiencyVSAvoidtraffic request management complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

STAs autonomously determine their own access probability based on locally generated random numbers and update rules, without requiring the AP to collect traffic requests or manage individual STA resources. Each STA independently decides whether to contend for random access based on its own random number comparison with the number of RUs, eliminating the need for complex traffic request collection and management at the AP

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The uplink channel is divided into multiple resource units (RUs) that can be independently selected by STAs. Instead of managing resources as a unified pool requiring complex allocation, the channel is segmented into discrete RUs that STAs can independently contend for based on their random access decisions

Inventive Principle:

Principle #1Segmentation

2Ease of operation

If multiple STAs contend for shared resources using random access, then resource allocation is simplified, but collisions and access conflicts increase

Engineering Contradiction:

Improveresource allocation simplicityVSAvoidaccess success rate

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

STAs dynamically adjust their access probability by updating random numbers based on comparison results with the number of RUs. This parameter change mechanism allows STAs to adapt their contending behavior - when RUs are abundant, access probability increases; when RUs are limited, access probability decreases, thereby reducing collisions while maintaining simple random access operation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The random access probability is made dynamic rather than static. STAs continuously update their random numbers based on previous comparison outcomes and current RU availability, creating a dynamic adjustment mechanism that responds to changing channel conditions and traffic patterns, balancing simplicity with collision reduction

Inventive Principle:

Principle #15Dynamics

3Productivity

If dedicated resources are allocated for uplink OFDMA, then resource management is precise and efficient, but flexibility and adaptability to varying traffic demands decrease

Engineering Contradiction:

Improveresource allocation efficiencyVSAvoidtraffic demand adaptability

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The same resource units (RUs) serve multiple purposes: they can be allocated to different STAs in different time slots, and the number of RUs can be dynamically adjusted based on traffic demand. The random access mechanism allows the same pool of RUs to adaptively serve varying numbers of STAs with varying traffic demands, providing both efficiency and flexibility

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses periodic trigger frames from the AP to initiate uplink OFDMA transmissions. Between trigger frames, STAs prepare their random numbers and access decisions. This periodic structure allows the system to re-evaluate and re-allocate RUs based on current traffic conditions in each transmission opportunity, providing adaptability while maintaining efficient resource utilization

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS9980292B2Contention based uplink orthogonal frequency-division multiple access (OFDMA)

Publication Date: 2018.05.22 MEDIATEK INC

AI summary

A method of performing contention-based uplink OFDMA transmission is proposed in accordance with one novel aspect. A wireless communications station (an AP) reserves both dedicated resource and contention resource for uplink OFDMA operation for a list of communications devices (STAs). For contention-based random access, the AP does not need to collect traffic requests from the STAs. The AP only needs to make simple resource arrangement. The AP only needs to specify the allocated resource for random access and the uplink OFDMA operation duration and timing for each uplink OFDMA packet. Each STA having traffic request will contend the resource based on a random access probability scheme.