SU-MIMO Type for Group Addressed Frames March 2011 doc.: IEEE 802.11-11/0313r0 March 2011 SU-MIMO Type for Group Addressed Frames Date: 2011-03-14 Authors: Jarkko Kneckt, Nokia Jarkko Kneckt, Nokia

March 2011 doc.: IEEE 802.11-11/0313r0 March 2011 Abstract The presentation describes means to detect: The BSSID (TA) of the BSS that transmitted the group addressed frame The group address (RA) of the transmitted frame The BSSID and group address detection from the VHT-SIG A enables group addressed receivers to skip the reception of unnecessary group addressed frames and to improve the non-AP STA power efficiency especially in the stand-by mode and in passive scanning. The presentation and normative text in 11-11-314r1 provide solution for CIDs: 124, 665, 666, 667, 669, 973 and 1341. Jarkko Kneckt, Nokia Jarkko Kneckt, Nokia

Recap, Address Indication in PLCP Header March 2011 Recap, Address Indication in PLCP Header 802.11ac is introducing new PLCP header format The PLCP header indicates the recipient(s) and transmitter of the PPDU Currently the PLCP header indicates: Individually addressed PPDU to single user (SU) The AID defines the recipient Individually addressed aggregated PPDU (A-PPDU) to multiple users (MU) The Group ID defines the recipients Group addressed PPDU The AID set to 0 indicates group address Jarkko Kneckt, Nokia

Challenges of the Address Indication in PLCP Header March 2011 Challenges of the Address Indication in PLCP Header Currently PLCP header has partial AID set to 0 for group addressed frames. There is no means to detect: Transmitter Address (BSSID) Receiver Address (group address) The current format forces STAs to receive all group addressed PPDUs Device cannot filter frames from other BSSIDs Devices cannot filter frames from unnecessary group addresses that it is receiving Jarkko Kneckt, Nokia

Solution, VHT-SIG A field of the PLCP header March 2011 Solution, VHT-SIG A field of the PLCP header Currently VHT-SIG A field is capable to indicate: 63 MU – MIMO groups 1 SU – MIMO transmission type VHT-SIG A field will be capable to indicate: 62 MU – MIMO groups 2 SU – MIMO transmission types Bit9 set to 1 for individually addressed PPDU, Partial AID in Nsts field Bit9 set to 0 for group addressed PPDU , Group Address Indication in Nsts field Jarkko Kneckt, Nokia

Solution, Group Address Indication March 2011 Solution, Group Address Indication Introduce GROUP_ADDR_IND: TXVECTOR GROUP_ADDR_IND[0:3] = BSSID[0:3] XOR BSSID[4:7] Identification of transmitter address (TA) TXVECTOR GROUP_ADDR_IND[4:7]= Group Address [0:3] Identification of receiver address (RA) TXVECTOR GROUP_ADDR_IND[8] = More Data bit Are more group addressed frames transmitted by the transmitter Details of the scheme are described in 11-11-XXXX-00-00ac-Indication-of-Group-Address.doc Jarkko Kneckt, Nokia

Stand-by Power Consumption March 2011 Stand-by Power Consumption In the stand-by the devices receive and transmit very little individually addressed frames The group addressed data generation may be the only received frames in the stand-by The device cannot control the amount of group addressed frames: Other BSSs may distribute a lot of group addressed frames A STA in BSS may generate and request a lot of group addressed frames transmission The reception of unnecessary group addressed frames increases the stand-by power consumption The stand-by power consumption defines the battery life time Jarkko Kneckt, Nokia

March 2011 Filtering of Frames STAs may stop reception of individually addressed frames to PLCP header The header contains indication of the transmitter and receiver addresses The current 802.11ac PLCP header has no means to specify the group address or transmitter of the PPDU The transmitter and group address are present in MAC header forcing to receive the whole MPDU FCS at the end of MPDU ensures the correctness of the frame The PLCP header filtering should be used for both the individually and group addressed frames The same operation simplify the implementation PLCP Synch + Header MAC Header Data Payload FCS Jarkko Kneckt, Nokia

Comparing the filtering efficiency March 2011 Comparing the filtering efficiency TXOP obtaining TXOP obtaining TXOP obtaining Operation flow: Beacon Group addressed PPDU Group addressed PPDU Time The SU-MIMO type for group addressed frames enable big increase to sleep durations. Jarkko Kneckt, Nokia

Summary The improved group addressed PPDUs handling enables: March 2011 Summary The improved group addressed PPDUs handling enables: Better addressing of the transmitted PPDUs More reliability and better understanding of the transmitted traffic Lower power consumption: The identifier for the transmitter of the group addressed frame enables filtering group addressed frames to other BSSs The identifier of group address enables to decide which frames to receive Especially the stand-by power consumption is reduced Jarkko Kneckt, Nokia

March 2011 Strawpoll Are you in favor of detecting the TA and RA of the group addressed frame from PLCP header in order to be able to filter group addressed frames and save power? Y N A Jarkko Kneckt, Nokia