1 Haiguang Wang, Jaya Shankar, Zhongding Lei A Method for Data Transmission Protection on the IEEE ac MU-MIMO DownlinkHaiguang Wang, Jaya Shankar, Zhongding Lei
2 ContentBackgroundProtect Data Transmission on IEEE ac MU-MIMO downlinkSummary
3 IEEE 802.11ac IEEE 802.11ac focus on high speed data transmission Transmission speed up to 1 GbpsRadio bandwidth up to 160 MHzUse MU-MIMO technologyWith MU-MIMO technology, AP can transmit multiple data packets to multiple stations at the same time.
4 Issues with MU-MIMO Technology One of the problems with MU-MIMO technology is how to protect data transmission.IEEE use contention-based data transmission.Legacy RTS/CTS can only provide partial protection over the MU-MIMO downlink transmission.Collision may happen when legacy stations is hidden to ac stations.RTS protection rangeCTS protectionrangeRTSCollisionCTSAP1STA1STA3AP2STA2STA4MU-MIMO Downlink
5 Possible Transmission Protection for 802.11ac MU-MIMO Downlink A few schemes can be used for transmission protection of ac MU-MIMO downlink, they are:Legacy RTS/CTSSingle RTS Multiple CTSMultiple RTS Multiple CTS
7 Single RTS Multiple CTS (2) We can also consider to send CTS at the same time.NAV protectionAPRTSxIFS timeSTA1CTSxIFS timeSTA2CTSxIFS timeSTA3CTSNAV distributing
8 Addressing Multiple Stations in RTS Single RTS multiple CTS can provide a better protection on data transmission than legacy RTS/CTS scheme. However, we need solve following issues:Address multiple stations in RTS.Compatible with legacy stations
9 Group AddressIEEE ac task group has defined a group ID at PHY layer.A group of stations may be assigned to the same group ID, which indicates that data transmitted in the packet are sent to the stations in this group.Group ID is sent in PHY layer
10 Using RTS-to-Self and Group ID for Addressing AP uses group ID directly as group MAC address.To avoid confusion caused by station with MAC address that is equivalent to a group ID, we propose to use RTS-To-Self with group ID in TA field.RTSAP1STA1AP2STA3STA2STA4
11 Advantage Simple in the implementation. Save the signaling exchange for group addressing.Compatible with legacy system
12 SummaryIn this proposal, we have propose a solution for IEEE ac standard in addressing multiple stations with a single RTS packet. The solution is compatible to legacy stations. We have also proposed solutions that may encounter in designing of Single RTS Multiple CTS.