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Reverse Direction in 802.11ac. Date: 2010-09-07. Authors:. Reverse Direction in 802.11n. RD gives an opportunity for a responder to transmit data to an initiator during the initiator’s TXOP. RD aggregates data with response control MPDUs. RD reduces Contention.
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Reverse Direction in 802.11ac Date: 2010-09-07 Authors: L. Chu et al
Reverse Direction in 802.11n • RD gives an opportunity for a responder to transmit data to an initiator during the initiator’s TXOP. • RD aggregates data with response control MPDUs. • RD reduces Contention. • RD is more effective in increasing TCP/IP performance. • DL-SDMA is a key technology to improve the overall 802.11ac network performance. • It is advisable to implement RD in 802.11AC.
Reverse Direction in 802.11n (Cont’d) • In HT Extended Capabilities field, RD Responder subfield is used to indicate if a STA supports for acting as a reverse direction responder. • In HT Control field, AC Constraint is used to indicate if the response to a reverse direction grant (RDG) may contain data frames from any TID. • In HT Control field, the RD initiator uses RDG/More PPDU subfield to indicate if reverse transmission is granted. • In HT Control field, the RD responder uses RDG/More PPDU subfield to indicate if the PPDU carrying the frame is followed by another PPDU. • 802.11AC does not have HT Extended Capabilities field and HT Control field.
Solutions • In Extended Capabilities field, RD Responder subfield is added. The added field has the same meaning of RD Responder field in HT Extended Capabilities field. • In VHTSIGB or VHTSIGA, AC Constraint subfield and RDG/More PPDU subfield are added. The added fields have the same meaning of AC Constraint subfield and RDG/More PPDU subfield in HT Control field. • Adding AC Constraint subfield and RDG/More PPDU subfield to VHTSIGA means that reverse operation is not allowed immediate following DL-MU frame. • The current reverse direction protocol defined in subclause 9.15 can be used without further change.
Straw Poll • Do you support adding the following item into the specification framework document, 11-09/0992? • 6.4: Reverse Direction shall be included in the specification to improve the MAC efficiency.