"Protocol data unit" . "segments" . . "PDUs" . "protocol" . . . "Application Protocol Data Unit (APDU)" . "Protocol Data Units" . "MPDU" . "Protocol data unit" . "Protocol data unit#MPDU" . . "PPDU" . "PDU" . "messages" . "protocol data unit" . "segment" . "Messages" . "Physical Layer PDU" . .