1. VHT Frame Padding - Summary
Month Year
doc.: IEEE yy/xxxxr0
VHT Frame Padding - Summary
Date:
Authors:
Yong Liu, Robert Stacey et al.
John Doe, Some Company

2. VHT Frame Padding
Yong Liu, Robert Stacey et al.

3. Summary
L-SIG length and rate are used to indicate PPDU duration (number of symbols)
The VHT format PPDU always carries an A-MPDU payload
The A-MPDU format used is an extension of the n A-MPDU
The extension consists of zero or more A-MPDU null subframes and a possible MAC Pad of less than 4 octets
The A-MPDU of a VHT PPDU fills the available octets in the payload
The A-MPDU null subframes that pad through the end of the frame shall include an EOF indication to allow the receiver to stop receive processing early to conserve power
Yong Liu, Robert Stacey et al.

4. Reference 11-10-0070-02-00ac-802-11ac-preamble.ppt
ac-vht-frame-padding.ppt
Yong Liu, Robert Stacey et al.

5. Spec framework changes (1)
Add a section on A-MPDU format under Frame Formats:
6.3 Frame formats
6.3.1 A-MPDU format
The VHT format PPDU always carries an A-MPDU payload. The A-MPDU format used is an extension of the n A-MPDU as shown in Figure YY. The extension (shaded in the figure) consists of zero or more A-MPDU null subframes (subframes with zero length MPDU) and a possible MAC Pad of less than 4 octets. The A-MPDU of a VHT PPDU fills the available octets in the payload.
Figure YY – A-MPDU format for VHT PPHU
Yong Liu, Robert Stacey et al.

6. Spec framework changes (2)
Add a requirement to the power saving section:
6.1 Power saving
R6.1.A: The A-MPDU null subframes that pad through the end of the frame shall include an indication that no additional MPDUs are present in the frame. This would allow the receiver to stop receive processing to conserve power.
Yong Liu, Robert Stacey et al.

7. Straw Poll
Should the spec framework document (09/992) be updated to include the changes shown on slide 5 and 6 of this presentation?
Yes No
Abstain
Yong Liu, Robert Stacey et al.