Wireless PPDU Retransmission Using Preamble-Only Block Acknowledgment
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Solution Overview
Problem
Existing wireless transmission protocols like IEEE 802.11 suffer from increased latency and overhead due to transmit failures, which are not efficiently addressed by conventional retransmission methods, leading to inefficiencies in CSMA/CA-based Wi-Fi communications.
Innovation Solution
Implementing a network device that sends a physical layer protocol data unit (PPDU) with a preamble indicating the recipient, receives a block acknowledgement (BA) upon payload failure, and resends the PPDU based on this feedback, utilizing BSS color and Station ID information to reduce latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If traditional wireless communication protocols are used, then compatibility and coverage are maintained, but latency is high and real-time responsiveness is poor
Solution Approach 1:
The wireless communication system is segmented into two distinct modes: first mode for traditional wireless communications (maintaining compatibility) and second mode for low-latency communications (enabling real-time responsiveness). This segmentation allows the system to operate in both modes simultaneously, resolving the contradiction between latency reduction and protocol compatibility.
Solution Approach 2:
The system dynamically switches between first and second communication modes based on the specific communication requirements. When low latency is needed, the system transitions to second mode; when compatibility is prioritized, it uses first mode. This dynamic adaptability resolves the contradiction by making the system flexible rather than fixed in its operational mode.
2Loss of time
If transmission time is reduced for low latency, then responsiveness improves, but error detection and correction capabilities deteriorate
Solution Approach 1:
The system performs error detection and correction operations in advance during the preparation phase, before the actual low-latency transmission occurs. This preliminary action allows the system to establish error correction capabilities ahead of time, so that when rapid transmission is needed, the reliability mechanisms are already in place and do not add to the transmission time.
Solution Approach 2:
The system maintains continuous error detection and correction processing during the communication session, ensuring that reliability functions operate continuously without interrupting the low-latency transmission flow. This continuous operation allows error correction to be performed without adding significant time delay to the transmission process.
3Speed
If processing operations are performed at higher speeds for real-time applications, then responsiveness improves, but power consumption increases
Solution Approach 1:
The system employs periodic action by switching between high-speed processing modes and normal processing modes based on the operational requirements. During periods when real-time responsiveness is critical, the system operates at higher speeds; during other periods, it operates at normal speeds to conserve energy. This periodic switching resolves the contradiction between processing speed and power consumption.
Solution Approach 2:
The processing speed of the system is made dynamic rather than fixed. The system automatically adjusts its processing speed based on the current operational context, transitioning between high-speed and normal-speed modes. This dynamic adjustment allows the system to achieve high processing speeds when needed while reducing power consumption during periods when maximum speed is not required.
Data Source
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AI summary
The present disclosure relates to reduce latency in wireless communications. To this end, the disclosure proposes a first network device being configured to: send a PPDU to a second network device, wherein the PPDU comprises a preamble and a payload, wherein the preamble comprises a first indication indicating that the payload is addressed to the second network device; receive a BA from the second network device, wherein the BA indicates that the second network device succeeded to decode the preamble but failed to decode the payload; and resend the PPDU to the second network device in response to the BA. Further, this disclosure also proposes a second network device being configured to: receive a PPDU from a first network device; and send a BA if only the preamble of the PPDU is successfully decoded, and it is detected that the payload is addressed to the second network device.