Hi Dani,

I was a bit busy with other things, hadn't had time to look into this
issue until now.

> Firmware Version: *2.3.7.0   *Candidate 2   and my speed is 72.0 Mbps
>  instead of 150 Mbps before the update.
Looking at these speeds and comparing them with the 11n supported
speeds, it looks like your connection is using a single antenna /
spatial stream (probably because your wifi network card only has one
antenna) and you're using single-channel / HT20 / 20Mhz mode (see
http://en.wikipedia.org/wiki/IEEE_802.11n-2009#Data_rates which shows
72.20 Mbps for MCS7 + short GI + 20Mhz channel). The 150Mbps you used to
get, is the same mode, but with a 40Mhz channel, so I suspect your HT40
mode has stopped working. Note that all of this is assuming that the
bitrates you mention are pretty exact, if you've seen 130Mbps and
written 150Mbs, this conclusion is probably different.

Some things that might help getting this working again:
 - In Settings -> Wireless, check if HT20/HT40 mode is set.
 - In the same page, check if the country is set correctly.

Furthermore, it seems that HT40 mode can also be automatically disabled
due to environmental conditions (e.g., other access points also using
the spectrum). The reasoning here is that running an AP in 40Mhz mode
uses around two-third of the availble 2.4Ghz spectrum, which can
cause severe interference when there are a lot of other APs around. In
my testing, I've seen 40Mhz mode work on one out of 5 associations, so I
suspect I'm seeing the same "interference autodetect" at work.

If this is indeed the case, then there's probably not much you can do,
except getting a wifi network card that actually has two antennas
(usually referred to as 2x2 or MIMO).

If you have Linux on your wifi client, could you send over the output of
the "iw dev wlan0 link" and "iw dev wlan0 scan dump" commands? If not,
perhaps you have some wifi connection utility that shows detailed
connection info (such as the MCS profile used and if the connection is
using HT20 or HT40)?

Also, on which firmware did you see the higher bitrate?

Gr.

Matthijs

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