When Acktype=0 and TID=13 received by a legacy STA, the presence of Block Ack Starting Sequence Control subfield and Block Ack Bitmap subfields would be considered as “N/A” , Legacy STA would take bits immediately after AID TID info subfield as the start of next Per AID TID Info field and could mistaken itself being addressed by this MBA. i.e. it does not know how many bits to skip to the next Per AID TID Info field.
• We prefer avoiding this. Current in the control frame
protection draft text in 11mf, the (Acktype, TID)=(0/1,0) for PN/MIC and padding is used such that legacy STA can parse this.
• If we must have this TID>7, suggest to add condition that the transmitter(s) of the soliciting PPDU does not include pre-UHR STAs
For “if the Multi-STA BA is individually addressed to the UHR STA, the AID11 subfield of the AID TID Info subfield is set to the 11 LSBs of the AID of a UHR STA”,
• Suggest change to “ if the Multi-STA BA is individually addressed to
a non-AP UHR STA, the AID11 subfield of the AID TID Info subfield is set to the 11 LSBs of the AID of
the UHR STA.
If the Multi-STA BlockAck frame is sent to an AP, the AID11 subfield is set to 0.”
Thanks!