80 MHz channel - Station data

[Ann Lo]

Hi,

When we set up 80MHz channel between AP and client station, we use the
iw station dump command to get the "rx bitrate" of the client station.
We have noticed that not only the MCS changes, the NSS also changes.
Is it normal to have dynamic values of NSS when we do iperf using 80
MHz channel?

Some data on "rx bitrate" of the same client station is as follows:

rx bitrate:     58.5 MBit/s VHT-MCS 1 80 MHz VHT-NSS 1
rx bitrate:     702.0 MBit/s VHT-MCS 5 80MHz VHT-NSS 3

We use kernel 3.14.28 and WLE900VX.

Thanks,
Ann