Downlink OFDMA Channel Allocation for Mixed Client Bandwidths
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Solution Overview
Problem
In wireless local area networks, the presence of legacy client devices with lower bandwidth capabilities can hinder the full utilization of wider bandwidth channels, leading to underutilization of AP resources and reduced efficiency, as they can block higher bandwidth devices from accessing the remaining bandwidth.
Innovation Solution
A wireless access point generates control parameters to assign non-overlapping channel bandwidths for downlink transmissions to client devices with different bandwidth capabilities, indicating timing for acknowledgments, and transmits a control frame to manage spectrum usage, allowing for efficient multiplexing and overlapping channel usage based on the capabilities of each device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the AP allocates wider bandwidth channels (80 MHz or more) to client devices, then the transmission speed and bandwidth utilization are improved, but legacy client devices that support only 20 or 40 MHz channels cannot access the network effectively, leading to reduced overall network efficiency
Solution Approach 1:
The 80 MHz bandwidth channel is segmented into multiple 20 MHz subchannels. The AP assigns different subchannels to different client devices based on their capabilities - legacy devices receive 20 MHz subchannels while modern devices receive wider bandwidth allocations. This segmentation allows simultaneous support for both legacy and modern devices without forcing the entire network to operate at the limited capacity of the slowest device.
2Ease of operation
If the AP transmits data to a legacy 20 MHz channel client device, then the legacy device can access the network, but all other client devices capable of operating with wider bandwidth channels are blocked from accessing the remaining bandwidth during the transmission
Solution Approach 1:
The patent introduces frequency dimension multiplexing by dividing the 80 MHz bandwidth into multiple 20 MHz subchannels. Instead of time-division multiplexing where legacy device transmissions block all other devices, the system allows simultaneous transmissions on different frequency subchannels. This dimensional change from time to frequency domain enables parallel access for legacy and modern devices, dramatically improving overall network throughput while maintaining legacy device accessibility.
3Adaptability or versatility
If the AP uses time-division multiplexing to serve legacy and modern devices sequentially, then device compatibility is maintained, but the available bandwidth is not fully utilized and network efficiency is reduced
Solution Approach 1:
The patent merges frequency-division multiplexing with downlink OFDMA to create a hybrid approach that simultaneously serves legacy and modern devices. By combining TDM for legacy device compatibility with FDM/OFDMA for modern device efficiency, the system achieves both device compatibility and high bandwidth utilization. Modern devices can utilize wider bandwidth channels while legacy devices access narrower subchannels, with both types of transmissions occurring simultaneously rather than sequentially.
Data Source
AI summary
Techniques are provided herein to allow a wireless network access point (AP) to more fully use its bandwidth in order to leverage the different bandwidth capabilities of different types of wireless client devices that the AP serves. The AP generates control parameters for usage of a plurality of channels in a bandwidth during a downlink transmission interval. The control parameters comprise information indicating channel assignments that result in multiple downlink transmissions that at least partially overlap in time to different wireless client devices according to their respective bandwidth capabilities. The AP transmits the control parameters in a control frame in advance of the downlink transmission interval on each of the plurality of channels in the bandwidth.