Disclosed herein are devices, systems and methods between a between a plurality of collaborating Access Points (APs) and a receiving station (STA) operating in a wireless local area network (WLAN). The method include the steps of: transmitting, by each AP in the plurality of collaborating APs, a data frame to the receiving STA, each data frame has a preamble portion, the preamble portion including a signal (SIG) field, and the SIG field has a subfield including information representative of a total number of spatial streams transmitted by the plurality of collaborating APs.