The latest ePMP 4xxx firmware allows MU-MIMO to be enabled.
My question is, will MU-MIMO gains be reflected in the “Total Frame Time Used” metric?
In other words: for a heavily utilized AP, will I see the impact of MU-MIMO by a reduced frame utilization during peak utilization? Or will the frame utilization make it look like the AP is maxed even though I’m getting gains from MU-MIMO?
Hello @sloach,
MU-MIMO gains are not directly reflected in the “Total Frame Time Used” metric. This metric shows the actual physical time spent transmitting downlink data, regardless of whether the transmission was single-user or multi-user.
So, in the case of MU-MIMO, even if multiple subscriber modules (SMs) are being served simultaneously in a single frame, the frame time used will still report the total airtime used — not how many users were served within that time. This means the metric may still show high utilization (even close to 100%) even though the system throughput has increased thanks to MU-MIMO.
WLR and TDD will have slightly different behavior. TDD driver as the most advanced checks if other groupable SMs have packets in queue. If the packets present MU-MIMO happens. If not, SU Beamforming is used for the first SM. Total frame time will be the same in both cases.
We’re considering enhancements, such as adding visibility into MU-MIMO efficiency or grouping metrics, to make this performance gain more transparent in the future.