A method by a second device for establishing via the second device, corresponding to a first access point, AP, a distributed multiple-input multiple-output, MIMO, joint transmission opportunity with one or more third devices, corresponding to second APs, to one or more first devices, corresponding to one or more stations, STAs, the method comprising: generating a first message, the first message identifying the one or more first devices for receiving one or more streams to be transmitted during the transmission opportunity, simultaneously from the second device and the one or more third devices; outputting the first message for transmission; outputting a first reference for transmission to the one or more third devices; wherein the first reference is output for transmission after the first message is outputted for transmission but before the one or more first devices receives the one or more streams; transmitting the first message to the one or more third devices and to the one or more first devices; wherein the first reference is being transmitted in a separate transmission included in a synchronization frame, to the one or more third devices; and outputting a second reference (810a-b) for transmission to the one or more third devices after outputting the first reference; wherein the second reference is output for transmission after the first message is outputted for transmission and after the first reference is output for transmission but before the one or more first devices receives the one or more streams; transmitting the second reference, included in a trigger frame (810a-b), to the one or more third devices; wherein a phase difference between the first reference and the second reference is indicative of a phase correction for use by the one or more third devices to transmit the one or more steams simultaneously with the second device during the transmission opportunity; and wherein, in response to the trigger frame, one or more streams are being transmitted (812a-b; 814a-b) during the transmission opportunity, simultaneously from the second device and the one or more third devices via a distributed MIMO joint transmission, the one or more third devices transmitting the one or more streams using the phase correction. generating a first message, the first message identifying the one or more first devices for receiving one or more streams to be transmitted during the transmission opportunity, simultaneously from the second device and the one or more third devices; outputting the first message for transmission; outputting a first reference for transmission to the one or more third devices; wherein the first reference is output for transmission after the first message is outputted for transmission but before the one or more first devices receives the one or more streams; transmitting the first message to the one or more third devices and to the one or more first devices; wherein the first reference is being transmitted in a separate transmission included in a synchronization frame, to the one or more third devices; and outputting a second reference (810a-b) for transmission to the one or more third devices after outputting the first reference; wherein the second reference is output for transmission after the first message is outputted for transmission and after the first reference is output for transmission but before the one or more first devices receives the one or more streams; transmitting the second reference, included in a trigger frame (810a-b), to the one or more third devices; wherein a phase difference between the first reference and the second reference is indicative of a phase correction for use by the one or more third devices to transmit the one or more steams simultaneously with the second device during the transmission opportunity; and wherein, in response to the trigger frame, one or more streams are being transmitted (812a-b; 814a-b) during the transmission opportunity, simultaneously from the second device and the one or more third devices via a distributed MIMO joint transmission, the one or more third devices transmitting the one or more streams using the phase correction.