Format of 802.11n Current Rate Field

[KaWg998053]

Hello,

there was another posting which explained the 802.11ac Current Rate Field in detail.

Unfortunately this doesn't aply on 11n rates.

I can see something like m7b2, m6-2, m5t2 on aironet 2700i ap.

I think the first digit is the mcs index and the last shows the bandwidth?

But what does the character in between mean? b=beamforming?

Even on classic ofdm rates like 54mbit there are sometimes characters appended like "54bf". What does that mean?

thank you!

[Rasika Nayanajith]

Here is the fomat

Format: aX.YcZ

X = mcs (modulation coding scheme) 0-9
Y = No of spatial streams, 1-3.
Z = Bandwidth 2, 4, 8 (2 = 20Mhz, 4=40Mhz, 8=80Mhz)
c = b for Beamform, s for STBC, - none
s = Guard Interval, indicates Short guard interval applicable over LGI (Long guard interval)

https://community.cisco.com/t5/wireless-mobility-documents/how-to-interpret-802-11ac-datarates/ta-p/3151995 

HTH

Rasika

*** Pls rate all useful responses *** 

[KaWg998053]

Thank you for your quick reply!

But i'm confused.

As far as i understand the format you mentioned (Format: aX.YcZ)  belongs to

802.11ac rates (configured with "speed a[x]ss[y]) which look like "a9.1-4", "a1.1-2" for example.

I know this and your quoted article.

But this doesn't apply on 802.11n rates. While setting with "m0.", "m1." and so on, the rates are reported back like mentioned as "m6b2", "m5t2", "m7-2".

What does "t" mean if b=beamforming?

And is "2" in the example the bandwith or number of spacial streams?

Is there any official documentation available?

I can't find anything in the Configuration Guide or Command Reference for autonomous aironet access points.