Mechanism Proposal to Improve Channel Switching Efficiency in IEEE 802.11 Networks
This document suggests a mechanism to enhance the efficiency of channel switching in IEEE 802.11 networks, particularly focusing on the NPCA primary channel. The proposal emphasizes the importance of timely switching back to the BSS primary channel to optimize medium synchronization and data transmission. Considerations regarding NPCA Transmission Threshold and Switch Back Delay are discussed to improve network performance.
Download Presentation
Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author. If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
You are allowed to download the files provided on this website for personal or commercial use, subject to the condition that they are used lawfully. All files are the property of their respective owners.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author.
E N D
Presentation Transcript
March 2025 doc.: IEEE 802.11-25/0538r0 Discussion on NPCA switch back Date: 2025-03-26 Authors: Name Affiliations Address Phone email Chaoming Luo OPPO luochaoming@oppo.com Liuming Lu OPPO Ning Gao OPPO Yapu Li OPPO Liangxiao Xin OPPO Submission Slide 1 Chaoming Luo, OPPO
March 2025 doc.: IEEE 802.11-25/0538r0 Abstract Proposes a mechanism to resolve CID 1783. CID Clause Comment 1780 37.10 The NPCA duration time is limited, STA is better to switch back to BSS P-channel early, instead of continue contending the NPCA P-channel incase the NPCA P- channel is busy Submission Slide 2 Chaoming Luo, OPPO
March 2025 doc.: IEEE 802.11-25/0538r0 Discussion The time a STA/AP stays on the NPCA primary channel is limited. Ideally, the STA/AP needs to switch back to BSS primary channel before basic NAV expires. If there are STAs (e.g., legacy STAs) do not switch to NPCA primary channel, it s more fair for an AP to switch back as early as possible considering about possible OBSS TXOP truncation. If a STA/AP switches back late more than 72 us, the STA/AP loses the medium synchronization on the BSS primary channel. [2] Then, what if the STA/AP does not gain channel access on the NPCA primary channel? Should it keeps retrying? There may be no enough time left to finish even a single MSDU transmission after it gain the channel access. Should it switch back to BSS primary channel immediately? When the basic NAV is long, there is possibility that it can retry and obtain a TXOP to finish data transmission. So, we need a balance! Submission Slide 3 Chaoming Luo, OPPO
March 2025 doc.: IEEE 802.11-25/0538r0 Proposal A simple solution: if the time left is less than a NPCA Transmission Threshold, the STA/AP switches back; otherwise, the STA/AP may keep retrying. The NPCA Transmission Threshold is a minimum time required to finish at least a single MSDU transmission on the NPCA primary channel: At least one EDCA backoff, consumes a minimum of PIFS, i.e., 25 us. At least one ICF + SIFS + ICR + SIFS sequence, consumes a minimum around 232 us. Assume ICF takes around 128 us (using non-HT PPDU or non-HT duplicate PPDU format using a rate of 6 Mb/s, 12 Mb/s, or 24 Mb/s), ICR takes around 72 us. At least one Data + SIFS + Ack/BA sequence, consumes a minimum around 160 us. Assume Data takes no less than 72 us, ICR takes around 72 us. At least a NPCA Switch Back Delay of the AP The NPCA Transmission Threshold is greater than or equal to the NPCA Switch Back Delay of the AP plus 417 us. We may use an arbitrary value to replace the NPCA Switch Back Delay of the AP, e.g., 252 us. The exact numbers could be discussed further. Submission Slide 4 Chaoming Luo, OPPO
March 2025 doc.: IEEE 802.11-25/0538r0 Straw Poll Do you support to add the following into the latest TGbn draft ? A NPCA Transmission Threshold field is added into the NPCA Operation Information field. The NPCA Transmission Threshold is a minimum time required to finish at least a single MSDU transmission on the NPCA primary channel. The NPCA Transmission Threshold is greater than or equal to the NPCA Switch Back Delay of the AP plus 417 us. Submission Slide 5 Chaoming Luo, OPPO
March 2025 doc.: IEEE 802.11-25/0538r0 References [1] Draft P802.11bn_D0.1 [2] 11-24-0496-01-00bn-secondary-channel-usage-follow-up [3] 11-24-0070-02-00bn-some-details-about-non-primary-channel-access [4] 11-23-1891-00-00bn-nonprimary-channel-access-follow-up Submission Slide 6 Chaoming Luo, OPPO
