The DL MU-MIMO transmissions can be organized in the form of MU-TXOP to facilitate the sharing of TXOP where 850 an AP can perform simultaneous transmissions to multiple receiving STAs by using the Group ID. Note that MU-TXOP requires at least a single STA, regardless of its access category (AC), to receive traffic from the AC that successfully obtained the TXOP instead of the original EDCA requirement where only transmission originating from the AC that won the TXOP is allowed. Finally, VHT TXOP power save is introduced so that a non-AP VHT STA could enter power save mode when it ascertains that it is not the intended recipient during that TXOP by filtering based on the RXVECTOR parameter of Group ID or partial association identifier (AID).