SYNCDesignDate:2014-12-10Slide1MarvellAuthors:
RecapofULOFDMAFrameExchangeA(duplicate)legacySYNCframe/HESYNC/NDPSYNCframeistransmittedinlegacyPPDUisusedtotriggeraULOFDMA/MU-MIMOframeexchange.FromSYNCdesignpointofview,legacySYNCandHESYNChavesameframeformat.ThedifferenceisthatSYNCframeisencapsulatedindifferentPPDUformat.SIFSaftertheendofPPDUwhichcarriesSYNC,STAstransmitULOFDMA/MU-MIMOframes.AfterreceivingULMUPPDU,theAPacknowledgesthereceivedframesbyusingbroadcastacknowledgeorOFDMAacknowledge.BlkAckBlkAckBlkAckDLSYNCSYNCSTA3A-MPDUtoAPSTA2A-MPDUtoAPSTA1A-MPDUtoAPOFDMAorbroadcastacknowledgeOFDMAFrameExchangeSYNCSYNCSYNCSlide2
SYNCFrameFormatSYNCframeisacontrolframe.RAisabroadcastMACaddress.TAistheMACaddressoftheAPthattransmitsSYNCframe.Duration/IDindicatesthetimeuntiltheendoftheTXOP.Padfieldisusedtopadtheframebodytomultipleoctetsifneeded.SYNCframeneedstoindicatetheSYNCbandwidthandtheULOFDMAbandwidth(sameasSYNCbandwidth)ScramblingsequenceandsignalingTAcanindicateSYNCbandwidth.BitsinHESIGcanbeallocatedtocarrySYNCandULOFDMAbandwidth.CommonInfoPerSTA/GroupInfoSTA0’sInfoorGroup0InfoSTAn’sInfoorGroupmInfo……PadSlide3
ResourceAllocationDiscussionInaULMUtransmission,thefollowingresourceneedstobedefinedbytheAP:TotalbandwidthoftheULMUtransmissionULPPDUlengthGItypeHE-LTFtypeSubchannelallocationforeachSTANSTSallocationforeachMUMIMOSTAInaULMUtransmission,thefollowingperSTAresourcemaybedefinedbyeithertheAPortheSTAs:BeamformingindicationTransmissionpoweroftheULtransmissionNSTSallocationforeachSUSTAMCSoftheULtransmissionSTBCindicationLDPCindication.TC/ACSlide4
SYNCCommonInfoCommonInfofieldincludesthefollowingsubfields:BWindicatingtotalbandwidthoftheULMUtransmission(2bitstoindicates:20MHz,40MHz,8