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Date: July, 2011. 9.19.2.5 Comment Resolutions. Authors:. Date: 2011-07-06. Comments. Date: July, 2011. PSMP TXOP Sharing VS DL MU-MIMO TXOP Sharing. Date: July, 2011. RA=STA1, ACVI. In a TXOP with PSMP, frames from multiple ACs can be transmitted.
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Date: July, 2011 9.19.2.5 Comment Resolutions Authors: Date: 2011-07-06 Liwen Chu Etc.
Comments Date: July, 2011
PSMP TXOP Sharing VS DL MU-MIMO TXOP Sharing Date: July, 2011 RA=STA1, ACVI • In a TXOP with PSMP, frames from multiple ACs can be transmitted. • 802.11REVmb already defines backoff procedure of PSMP TXOP sharing. • In DL MU-MIMO TXOP sharing, frames from multiple ACs can be transmitted. • DL MU-MIMO TXOP sharing can use the current 802.11 REVmbbackoff procedure. BlkAck Req BlkAck Req RA=STA2, ACVE VHT AP RA=STA3, ACVI BlkAck VHT STA1 BlkAck VHT STA2 BlkAck VHT STA3 RA=STA1, ACVI RA=STA2, ACVE RA=STA3, ACVI PSMP VHT AP PSMP DTT2 PSMP DTT1 PSMP DTT3 BlkAck VHT STA1 PSMP UTT1 VHT STA2 RA=AP, ACVE PSMP UTT2 RA=AP, ACVI VHT STA3 PSMP UTT3
PSMP Backoff and Retransmission PSMP does not require backoff procedure change. There is no new rules for internal collision even if PSMP TXOP supports TXOP sharing. Whichever frame transmission fails, only the backoff parameters of the AC acquiring TXOP is influenced. When the transmission of the TXOP is successful, only the backoff parameters of the AC that acquires the TXOP are adjusted. The normal multiple frame transmission rules are used for PSMP. The valid respond to the initial frame means that the TXOP holder can transmit multiple frames. Date: July, 2011 PIFS RA=STA1, ACVI RA=STA2, ACVE RA=STA3, ACVI PSMP PSMP VHT AP PSMP DTT3 PSMP DTT2 PSMP DTT1 BlkAck VHT STA1 PSMP UTT1 VHT STA2 RA=AP, ACVE PSMP UTT2 RA=AP, ACVI VHT STA3 PSMP UTT3 AC VI’s backoff timer counts to 0. AC VE’s backoff parameters keep the same. RA=STA1, ACVI RA=STA2, ACVE PSMP VHT AP PSMP DTT2 PSMP DTT1 The TXOP holder decides to do backoff instead of PIFS recovery. BlkAck VHT STA1 PSMP UTT1 VHT STA2
DL MU-MIMO Backoff and Retransmission Date: July, 2011 • DL MU-MIMO does not require backoff procedure change. • This follows PSMP backoff rules. • Since the secondary AC may be any AC and the frames of the related AC may belong to STAs other than DL MU-MIMO destinations, internal collision resolution makes backoff complicated. • When the secondary ACs collide with the primary AC, REVmb’s rule is used for secondary ACs. • Whichever frame transmission fails or succeeds, only the backoff parameters of the AC acquiring TXOP is influenced. • The normal multiple frame transmission rules are used for DL MU-MIMO TXOP sharing. • The blockack of MU-MIMO PPDU without blockackReq is the valid respond to the initial frame. • The valid respond to the initial frame means that the TXOP holder can transmit multiple frames. RA=STA1, ACVI PIFS BlkAck Req BlkAck Req BlkAck Req RA=STA2, ACVE VHT AP RA=STA3, ACVI BlkAck VHT STA1 BlkAck VHT STA2 BlkAck VHT STA3
Proposed Resolution Discussion:PSMP also allows (AC) TXOP sharing. PSMP does not require new backoff and TXOP acquiring rules. So the current backoff, TXOP obtaining rules can be used to DL MU-MIMO TXOP sharing without change. Proposed resolution: Disagree Date: July, 2011
Comments Date: July, 2011 • Discussion: This note is from the 802.11 REVmb draft. The reason is to guarantee fairness among STAs. The commenter is encouraged to submit the comment to 11 REVmb. • Proposed resolution: Disagree
Comments Date: July, 2011 • Discussion: 802.11 ac draft 1.0 adds the following sentence in section 9.19.2.3 “All references to medium idle and medium busy within this subclause refer specifically to the medium condition on the primary channel”. This can cover the deleted 11n case and not change the behavior for 11n STAs. • Proposed resolution: Disagree