Who's on First?

[yeti]

Use gedit to copy and save this little snippet to your /home/mint folder
as the file 'Channel', then with an xterminal do chmod +x Channel.
(replace my wlan1 with your own wifi's device name)

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#!/bin/bash
# Assess strengths of those on wifi Channel $1 
sudo iwlist wlan1 scan | grep -e Freq -A 3 |
grep "(Channel $1)" -A 3 | grep -v key 

Experiment 1, for your homework:

The next time you are on line with wifi, and you know you are on wifi Channel 1,
in an xterminal while you're in /home/mint enter the command ./Channel 1,
and you may find out who else is on your channel. In my case I get:

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mint@mint ~ $ ./Channel 1
                    Frequency:2.412 GHz (Channel 1)
                    Quality=45/70  Signal level=-65 dBm  
                    ESSID:"BUXL3"
--
                    Frequency:2.412 GHz (Channel 1)
                    Quality=27/70  Signal level=-83 dBm  
                    ESSID:"WARnet"

BUXL3 is my router. WARnet is my neighbor, and luckily he's 18 dB weaker.

In my area, only Channels 1, 6 and 11 are used. YMMV on this.

Experiment 2, homework for some who have a lot of wifi neighbors on your own Channel:

a. Use iwconfig wlan1, if wlan1 is your wifi and see what you get for Tx-power.
b. If your Tx-power is 20 dBm or more, reset it to 5 dBm;
that is, do iwconfig wlan1 txpower 5, then do iwconfig wlan1 again to see if txpower changed.
c. If your txpower is now 5 dBm, recheck your Channel;
after a few minutes there should be fewer apparent neighbors.
d. Discuss what this might mean.