OFDMA Random Access Contention Group Assignment
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Solution Overview
Problem
In wireless communication systems, especially in high-density scenarios, Orthogonal Frequency-Division Multiple Access (OFDMA) random access (OFDMA-RA) experiences a significant decrease in sub-channel contention success rate due to increased collisions among contending electronic devices.
Innovation Solution
The implementation of contention groups, where electronic devices are explicitly or implicitly assigned to specific groups based on criteria such as association identifiers, traffic type/quality of service, power saving preferences, and association status, to reduce collisions by controlling the OFDMA-RA channel access mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If OFDMA-RA is used for uplink channel access in high-density scenarios, then channel access capability is improved, but collision rate increases significantly
Solution Approach 1:
The patent segments the contending electronic devices into multiple contention groups (e.g., first contention group and second contention group). Each group is assigned to different OFDMA-RA sub-channels or resource units, thereby dividing the single large contention into multiple smaller contending groups. This segmentation reduces the collision probability within each group while maintaining overall channel access capability.
2Quantity of substance
If the number of contending electronic devices increases, then network coverage and connectivity are improved, but OFDMA-RA sub-channel contention success rate decreases
Solution Approach 1:
The patent applies segmentation by dividing the large number of contending devices into multiple contention groups that contend on different sub-channels or resource units. This allows the system to support a larger total number of devices while maintaining acceptable contention success rates within each segmented group.
Solution Approach 2:
The patent introduces an additional dimension for channel access by utilizing multiple OFDMA-RA sub-channels or resource units. Instead of all devices contending on a single sub-channel, devices are distributed across multiple sub-channels, effectively adding a frequency-domain dimension to the contention process and reducing collisions.
3Reliability
If explicit contention group assignment is implemented, then collision reduction is achieved, but system complexity increases
Solution Approach 1:
The patent implements self-service by allowing electronic devices to autonomously determine their own contention group assignments based on pre-defined criteria such as device identifiers, traffic types, or QoS requirements. The access point broadcasts the contention group configuration, and devices independently map themselves to appropriate groups without requiring complex centralized assignment procedures, thereby reducing system complexity while maintaining collision reduction benefits.
Data Source
AI summary
Some embodiments are directed to grouping electronic devices into contention groups to reduce uplink Orthogonal Frequency-Division Multiple Access (OFDMA) random access (OFDMA-RA) collisions. An access point may explicitly assign an electronic device to a contention group, or the electronic device may implicitly determine an assignment to the contention group. To explicitly assign a device to a contention group, the access point may randomly assign or assign based on a criteria of the electronic device. Examples of criteria include an association identifier (AID), a traffic type/quality of service (QoS) category, a power saving preference, and an association status. The electronic device may implicitly determine a contention group assignment based on the total number of contention groups. The electronic device may use the explicitly or implicitly assigned contention group number to determine whether the electronic device may contend for a given trigger frame random access (TF-R) frame.