Change channel to lower wireless signal interference

[artsown]

Linux provides a scanner that collects considerable information on
various other users (your neighbors) in a wireless LAN. Each user
is assigned a arbitrary cell number. To collect the information type
the following in a terminal:

iwlist wlan0 s > list.txt

It may take several seconds to do the scan. The text file list.txt is
written to /root by default. Note that you may need to use wlan1
instead of wlan0, etc.

I've taken a sample list.txt and deleted all information not relevant
to my subject:

wlan1 Scan completed :
Cell 01 - Channel:3
Quality=70/70 Signal level=-35 dBm
ESSID:"linksys"

Cell 02 - Channel:11
Quality=27/70 Signal level=-83 dBm
ESSID:"DIRECT-C1-HP ENVY 5660 series"

Cell 03 - Channel:11
Quality=70/70 Signal level=-40 dBm
ESSID:"mizmario2"

Cell 04 - Channel:44
Quality=29/70 Signal level=-81 dBm
ESSID:"mizmario5"

Cell 05 - Channel:6
Quality=27/70 Signal level=-83 dBm
ESSID:"Shady"

Cell 06 - Channel:11
Quality=27/70 Signal level=-83 dBm
ESSID:"STEWART"

Cell 07 - Channel:11
Quality=26/70 Signal level=-84 dBm
ESSID:"HAYNARD"

Cell 08 - Channel:36
Quality=27/70 Signal level=-83 dBm
ESSID:"belkin.b02.5GHz"


Here, my cell happens to be 01. Notice the strong (interference) signal
from cell 03. I try to avoid using channels (frequencies) others are using,
and in particular I definitely want to use a channel other than 11. I set my
router to channel 3.

If my house had aluminum siding on the outside wall behind the router,
that would shield and attenuate the strong interference signal. But it's
simpler and less expensive to simply avoid the interfering frequency

I'll note here that the strong signal I'm getting is due to my use of a
PCI-e wireless adapter having three antennas. The router is about 30
feet away and there are two large rooms and two walls between router
and receiving antennas.

Art

[Flash]

Actually you only went halfway. You didn't tell us how you changed the channel.

[artsown]

Hi Flash. In your (wireless) router setup there should be a place where you
can set the channel #. Exactly where will vary with the particular router
you have.

Art

[bigpup]

Thanks for this information.

I always wondered if there was a way to tell what channel other wifi in area were using.
After doing the check using the command you posted.
I find I am the only one using channel 6.

Selecting the proper WiFi channel can significantly improve your WiFi coverage and performance. In the 2.4 GHz band, 1, 6, and 11 are the only non-overlapping channels. Selecting one or more of these channels is an important part of setting up your network correctly.

Each channel on the 2.4 GHz spectrum is 20 MHz wide. The channel centers are separated by 5 MHz, and the entire spectrum is only 100 MHz wide. This means the 11 channels have to squeeze into the 100 MHz available, and in the end, overlap.

However, there are three channels that don’t overlap: 1, 6 and 11. Co-channel interference is where devices take turns talking, so the more devices on one channel, the longer it takes for a device to talk since it has to wait for its turn.

Channel 11 seems to be used a lot, as the default channel, set by the manufactures. At least, all the wifi routers I have used, were preset to channel 11.

The 5GHz wifi devices are a big improvement for several reasons.

5 GHz
24 non-overlapping channels.
Little WiFi congestion
Very little non-WiFi interference

[8Geee]

Puppy has a GUI for that called "Network Wizard" by Dougal. Path is Menu--> Setup--> Internet Connection Wizard, and click on Network Wizard. Upon wifi attempt, it will show all nearby servers/clients and their channel. As previously mentioned set up router to be far from strong signals. (Example if Strong on 11 and 6... try 8 or 9, or go low to 2,3,or 4. Much of my local is 1 6 10 11 weaker on 1 and 6, so going low is OK on 3 or 4. YRMV)

Regards
8Geee

[bigpup]

Thanks for this info!

Puppy has a GUI for that called "Network Wizard" by Dougal. Path is Menu--> Setup--> Internet Connection Wizard, and click on Network Wizard.

I knew it would show other wifi signals in the area, but not the channel being used.

To be a little clearer on how to use Network Wizard.
When you select scan to see what wifi signals are available.
A list of what is found in area is made.
The list is the names of the wifi routers found and if encryption on/off.
To see info about the channel used. Hover over the router name and more info will show.

[Burn_IT]

One thing you need to know about the 5Ghz band is that it is only useful very locally as the signal has very poor penetration.

[artsown]

For those wanting a nice gui app, I suggest:
https://sourceforge.net/projects/linssid/
You can d/l a deb from there. I installed mine via the ppm of bionicpup64
7.9.8 beta.

Art

[bigpup]

Thanks!
That is a good GUI to show what wifi signals are in area and how they relate to each other.