MU-MIMO Explained: Uplink, Downlink and Spatial Streams
A wireless access point has a fixed amount of airtime, and traditionally it spent that airtime on one client at a time. MU-MIMO changes that: multiple clients, simultaneously, on the same channel, separated in space rather than in time. The word that matters is multi-user . SU-MIMO — single-user — also uses multiple antennas, but it points all of them at one device to make that one connection faster. MU-MIMO points different spatial streams at different devices at once. Both improve throughput; only one improves how many clients an AP can serve well. How Spatial Separation Works An access point with multiple antennas can shape the phase and amplitude of its transmissions so that signals reinforce at one client's location and cancel at another's. Done across several clients at once, each receives its own stream with the others appearing as background. This depends entirely on the clients being in meaningfully different physical positions with distinct channel characte...