Finding a place in an internet crowd.

[utu]

.
I know the 2.4 GHz wifi band has eleven channels, but I think it has been shown
that it is better to be on channel 1, 6 or 11 and not somewhere in-between.
I assume it then is better to be on one of these three where your signal is
better than other competing users on that channel. Better is a smaller negative
dBm number. -35 is 'much better' than -80, for example.

Knoppix's NetworkManagerApplet gives visual indications of competing user's
signal strength, but does not help show who's on which channel. In my neighborhood,
there are currently twenty-two internet subscribers. They have independently
chosen to align themselves almost uniformly in only the three channels 1, 6 and 11.
I found it handy to have a small alias program channel_1, to help me decide which
channel to select for myself. As root, I put this in /etc/profile:

alias channel_1="sudo iwlist wlan0 scan | grep -e Freq -A 3 > text; less text | grep '(Channel 1)' -A 3 | grep -v key"

Then, as knoppix when I enter channel_1, I get something like:

knoppix@Microknoppix:~$ channel_1
                    Frequency:2.412 GHz (Channel 1)
                    Quality=45/70  Signal level=-65 dBm  
                    ESSID:"belkin.594"
--
                    Frequency:2.412 GHz (Channel 1)
                    Quality=21/70  Signal level=-89 dBm  
                    ESSID:"K7964"
--
                    Frequency:2.412 GHz (Channel 1)
                    Quality=29/70  Signal level=-81 dBm  
                    ESSID:"HP-Print-57-Officejet Pro 8600"
--
                    Frequency:2.412 GHz (Channel 1)
                    Quality=23/70  Signal level=-87 dBm  
                    ESSID:"E5JA2"
--
                    Frequency:2.412 GHz (Channel 1)
                    Quality=23/70  Signal level=-87 dBm  
                    ESSID:""

Obviously one may easily coopt 'channel_1' into 'channel_6' or 'channel_11' easily enough
not to require anything more elegant or comprehensive.
In this example, Channel 1 looks like a good choice for my Belkin router.

[utu]

.
Here's a modest refinement which works for 'all wifi channels', although
in the US there's just 1 thru 11, and in my neighborhood, only 1, 6 & 11
are used. I've replaced the former alias statement in /etc/profile with
a similar, more general function definition. The function Channel is
defined as follows:

Channel() { # Summarize current state of a wifi channel.
sudo iwlist wlan0 scan | grep -e Freq -A 3 | grep '(Channel '$1')' -A 3 |
     grep -v key | grep -v Freq 
}

When I enter Channel 1, for example, I get the following, now:

knoppix@Microknoppix:~$ Channel 1
                    Quality=61/70  Signal level=-49 dBm  
                    ESSID:"belkin.594"
--
                    Quality=26/70  Signal level=-84 dBm  
                    ESSID:"Amped_SR"
--
                    Quality=24/70  Signal level=-86 dBm  
                    ESSID:"HP-Print-57-Officejet Pro 8600"
--
                    Quality=23/70  Signal level=-87 dBm  
                    ESSID:""
--
                    Quality=22/70  Signal level=-88 dBm  
                    ESSID:""
--
                    Quality=22/70  Signal level=-88 dBm  
                    ESSID:"E5JA2"
--
                    Quality=23/70  Signal level=-87 dBm  
                    ESSID:""