Hi Dani,

> I updated my 2.0n   but my speed is down from 150 Mbps to 72 Mbps.
> How can I bring the speed back to 150 Mbps??

You mentioned this before and I did some investigation about it, but
looking back it looks like I forgot to report back to you about this.

What I've found is that the 150Mbs speed is using HT40 mode (which uses
40Mhz wide channel, instead of the normal 20Mhz wide channel). HT40 mode
is a way to increas bandwidth, but it greatly increases the spectrum
usage and interference (IIRC the 40Mhz channel takes up over 3/4 of the
2.4Ghz spectrum).

To prevent issues with other people's access points, the Fonera scans
the spectrum and only enabled HT40 mode when there are not so many
conflicting access points nearby. In 2.3.6.1, this check was broken, so
it enabled HT40 mode even when it should not. In 2.3.7.0 this check
works as expected, so this limits the speed in order to reduce
interference.

Note that there is a second way to increase speed in 802.11n. In
addition to using a wider channel, it can also use multiple "spatial
streams". This means the two antennas are both used to carry different
signals through the same channel. Looking at the speeds you mentioned,
you are currently not using this "MIMO" or 2x2 technology, probably
because your wireless card / dongle does not support it. If you would
swap out the wireless card with one that supports 2x2 operation, you
could get up to 144Mb/s.

I hope this answers your question?

Regards,

Matthijs Kooijman

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