[asterisk-users] moving WiFi phone

[Noah Miller]

> > I, too, have heard about that best practice of using different
> > channels for different AP's on the same SSID.  As far as I can tell,
> This is standard textbook stuff. Read Cisco press's 'Deploying License
> Free Wireless Wide-Area Networks' by Jack Unger.
> > it's BS.  I don't know who started it, but it has never worked in any
> > of the situations I've encountered.  In fact, I know of at least one
> > AP manufacturer (Apple) that has a utility to auto-configure WDS
> > networks, and it auto-configures to use the same channel.  That's
> Using the same channel is bad, because the APs will interfere with each
> other and your throughput will be reduced. Imagine if you have a total
> of 2 APs with 10 clients each, the bandwidth will have to be shared
> amongst the 22 devices. So, if you're able to get 54Mbps on that
> channel, the net result is everybody gets 54/22 = 2.45Mbps each. Not a
> very pretty sight.
>
> Roaming with multiple APs on the same channel is OK for small set ups.

I don't know where one might draw a line between a small and a large
setup, but I did one with 15 AP's over a floor of a high-rise.  I
intially tried the textbook method of different channels, and found
the network to be totally useless for either roaming or throughput.  I
put them all on the same channel and everything was fine.  In this
case, there were also literally 25 other wireless networks in range
with very strong signals (gotta love NYC). I think the moral of the
story is that the particular situation will dictate whether or not to
use different channels.  In a perfect world of evenly distributed AP's
with no outside interference, it probably works well to use different
channels for adjacent AP's (except for roaming Wifi phones).  In a
real-world situation with all sorts of 2.4Ghz interference, a single
channel may work better.  Of course, YMMV.

- Noah