Fig. 4From: Solving hidden terminal problem in MU-MIMO WLANs with fairness and throughput-aware precoding and a degrees-of-freedom-based MAC designFrame formats and basic channel sounding process. The figure shows the channel sounding process and the frame formats used for channel sounding. We present the channel sounding process considering the ith network AP2 and clients from both the ith and the jth networksBack to article page