MU-MIMO Reverse Direction Duration Grant Mechanism
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Solution Overview
Problem
Current wireless communication standards, such as IEEE 802.11ac and 802.11ax, do not support reverse direction (RD) for multi-user multiple-input multiple-output (MU-MIMO) communications, which limits uplink channel access efficiency and user experience in applications requiring bi-directional communication, like virtual reality, where simultaneous downlink and uplink data transfers are necessary.
Innovation Solution
The implementation of an MU-MIMO RD duration system that allows bi-directional communication during a transmit opportunity (TXOP) period by using reverse direction grants (RDG), block acknowledgments, and quality of service (QoS) frames to enable RD data transmission from multiple devices to an initiator device without channel access delays, utilizing existing frame structures like MU-PPDUs and Duration/ID fields to set and align RD durations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If reverse direction communication is not supported in MU-MIMO, then downlink multi-user communication can be maintained, but uplink channel access efficiency deteriorates due to channel access delays
Solution Approach 1:
The initiator device预先 grants reverse direction permissions to responder devices during the downlink phase, allowing them to transmit uplink data without waiting for channel access. The RDG field in downlink frames预先 authorizes responders to use the channel in reverse direction during the specified RD duration, eliminating the need for separate channel access procedures.
Solution Approach 2:
The system dynamically allocates reverse direction duration (RD duration) within the transmit opportunity (TXOP) based on uplink traffic requirements. The RDG field and Duration/ID field work together to flexibly define the time window for reverse direction transmission, adapting to different application scenarios such as virtual reality where tight uplink response times are critical.
2Ease of operation
If bi-directional communication is not enabled during TXOP, then channel access control is simplified, but user experience in applications requiring simultaneous downlink and uplink deteriorates
Solution Approach 1:
The transmit opportunity (TXOP) is segmented into distinct phases: downlink transmission phase and reverse direction phase. During the downlink phase, the initiator transmits to multiple responders. The RDG field indicates which responders are authorized to transmit in the subsequent reverse direction phase, enabling structured bi-directional communication while maintaining clear channel access control.
Solution Approach 2:
The downlink frames serve multiple functions: they carry data transmission, channel reservation information (via Duration/ID field), and reverse direction grants (via RDG field). This multi-functionality allows the same frame structure to control both downlink and uplink communications, simplifying the overall channel access mechanism while enabling bi-directional data flow.
3Adaptability or versatility
If RD duration is not aligned with TXOP, then flexibility in duration setting is improved, but channel access coordination and latency performance deteriorate
Solution Approach 1:
The initiator device calculates and sets the RD duration in advance, aligning it with the TXOP boundaries. The Duration/ID field in downlink frames contains this pre-calculated RD duration, allowing responder devices to know exactly when they can begin reverse direction transmission. This preliminary setup eliminates coordination delays during actual transmission.
Solution Approach 2:
The system creates a synchronized time reference framework where all devices share the same TXOP timing. By aligning RD duration with TXOP boundaries and using the Duration/ID field to communicate this timing information, all devices operate on the same time baseline, eliminating timing conflicts and coordination overhead.
Data Source
AI summary
This disclosure describes systems, methods, and devices related to reverse direction duration. A device may establish a multi-user multiple-input multiple-output (MU-MIMO) communication with one or more station devices. The device may determine a frame to be sent to the one or more station devices, wherein the frame includes at least one of a duration field or a reverse direction indication. The device may cause to send the frame to the one or more station devices.