A method for orthogonal frequency division multiple access, OFDMA, communication in a wireless local area network including an access point, called AP, and a plurality of client stations, called STAs, comprising: obtaining by the AP of exclusive control of a wireless communications medium including a plurality of sub-channels for a time period; determining by the AP of an allocation of one or more sub-channels to certain ones of the STAs for use in said time period for OFDMA communications; and sending by the AP at a beginning of the time period on each of the plurality of sub-channels of a control frame including for each of said certain ones of the STAs: a) an identification of the STA; b) an identification of one or more sub-channels allocated to that STA; and c) an identification of a bandwidth to use for communications with that STA; wherein said control frame specifies whether the OFDMA communications with the certain ones of the STAs during said time period after the sending of the control frame are to be down-link communications from the AP to the certain ones of the STAs; characterized by the fact that said method further comprises sending by the AP of simultaneous Aggregated MAC Protocol Data Unit, called A-MPDU, communications using OFDMA to the certain ones of the STAs, said simultaneous A-MPDU communications having a same start time (t0) and same finish time (t1) within said time period, each A-MPDU communication including a physical layer protocol data unit , called PPDU, said PPDU including a physical layer convergence procedure header , called PLCP, including signaling information, and by the fact that said method further comprises sending by the AP in the PLCP header a first signaling information field including a flag specifying whether the PPDU of the A-MPDU communication is an OFDMA communication, and sending by the AP in the PLCP header a second signaling information field specifying for the STA the one or more sub-channels allocated to that STA. obtaining by the AP of exclusive control of a wireless communications medium including a plurality of sub-channels for a time period; determining by the AP of an allocation of one or more sub-channels to certain ones of the STAs for use in said time period for OFDMA communications; and sending by the AP at a beginning of the time period on each of the plurality of sub-channels of a control frame including for each of said certain ones of the STAs: a) an identification of the STA; b) an identification of one or more sub-channels allocated to that STA; and c) an identification of a bandwidth to use for communications with that STA; wherein said control frame specifies whether the OFDMA communications with the certain ones of the STAs during said time period after the sending of the control frame are to be down-link communications from the AP to the certain ones of the STAs; characterized by the fact that said method further comprises sending by the AP of simultaneous Aggregated MAC Protocol Data Unit, called A-MPDU, communications using OFDMA to the certain ones of the STAs, said simultaneous A-MPDU communications having a same start time (t0) and same finish time (t1) within said time period, each A-MPDU communication including a physical layer protocol data unit , called PPDU, said PPDU including a physical layer convergence procedure header , called PLCP, including signaling information, and by the fact that said method further comprises sending by the AP in the PLCP header a first signaling information field including a flag specifying whether the PPDU of the A-MPDU communication is an OFDMA communication, and sending by the AP in the PLCP header a second signaling information field specifying for the STA the one or more sub-channels allocated to that STA. <EOS>