It is expected that 5G is made up of several radio access technologies as there is probably no single technology capable of meeting all requirements. Richard van Nee received the M.Sc. degree in Electrical Engineering from Twente University in Enschede, the Netherlands, in 1990, followed by a Ph.D, degree from Delft University of Technology in 1995. The downlink MU-Multiple Input Multiple Output (MIMO) throughput advantage is now extended to the uplink in 802.11ax by introducing uplink MU-MIMO. There are different power levels depending on bandwidth with higher defer level for larger bandwidth modes. The lower the transmit power, the higher the defer threshold. The reasoning is that a station with lower transmit power causes interference over a smaller range, hence it can increase its defer threshold such that it defers only for relatively nearby other stations.