cancel
Showing results for 
Search instead for 
Did you mean: 

Wireless channel selection

shutter
Community Veteran
Posts: 22,206
Thanks: 3,769
Fixes: 65
Registered: ‎06-11-2007

Wireless channel selection

I have just moved home.... ( and it went perfectly !  Wink ).... however, I am now in amongst a high residential area, with lots of wireless routers being picked up by  inSSIDer...
At present I am on Channel 1.... with 2 others  (BT Openzone  + BTFon ) There a couple on ch4 , 1 on ch6, and 5 on ch11....
bearing in mind there is an overlap into nearby channels, (2 chans either side of the chosen one) , I seem to have chan 7or 8 as the best choice.
My current signal strength on the trace is twice that of any others,  (apart from chan 6 [sky} which is 2/3rds my sig level) so will moving to 7 or 8 make any difference to my speed/interference(?) from the current channel setups?
( I`m guessing the sky on ch6 is next door !)
8 REPLIES 8
ejs
Aspiring Hero
Posts: 5,442
Thanks: 631
Fixes: 25
Registered: ‎10-06-2010

Re: Wireless channel selection

There are about 3 non-overlapping channels: 1, 6, and 11 (well, it depends on how you use channels 12 and 13).
So according to inSSIDer, channel 7 or 8 would be a worse choice. Why would you want to overlap with the nearest neighbouring network?
However, inSSIDer doesn't really show the whole picture:

  • It doesn't show non wifi RF interference.

  • It doesn't show the number of devices using each router nor how much traffic they transmit, and the some devices might be nearer to you than their router.


In addition:

  • The beacons packets that inSSIDer receives are transmitted at the lowest bitrate, usually 1Mbit, and consequently have much longer range than data packets. For many neighbouring networks, a few beacon packets will be all you'll ever receive from them. You would struggle to connect to a network that far away.

  • Some of the neighbouring access points might automatically choose another channel if you change channel.

shutter
Community Veteran
Posts: 22,206
Thanks: 3,769
Fixes: 65
Registered: ‎06-11-2007

Re: Wireless channel selection

Thanks for the reply....
I was considering 7 or 8 as they are "overlapped" by neighbouring signal channels, because my thinking was that this would receive less interference from the outer edges of the neighbouring channel bounds, rather than being on exactly the same channel as a neighbouring signal channel.... which I assume would receive more/ higher power interference than adjacent channel(s)

pierre_pierre
Grafter
Posts: 19,757
Thanks: 3
Registered: ‎30-07-2007

Re: Wireless channel selection

thought you would be on a barge going down the Thames
The trace below is from my current location, becuse of the levels, none interfere with me.
At home I have a couple who are using a nuisance type of router that occupies say from chan 1 right up to 10 in one hit, but they are a low enough signal not to worry  (they are both from the TT stable)  a road opposite me also has about the same number of BT fon lots, done know how they sort themselves out, again not my problem
ejs
Aspiring Hero
Posts: 5,442
Thanks: 631
Fixes: 25
Registered: ‎10-06-2010

Re: Wireless channel selection

You are missing the idea about using non-overlapping channels - and everyone seems to use the term "interfere" loosely.
When 2 wifi networks share the same channel, they can understand each other's transmissions and co-exist reasonably well, because they avoid talking over each other.
If one network uses channel 6 and another uses channel 8, they only receive one half of the other's transmissions, which they can't understand, so they won't avoid talking over each other, and then it is the same as non-wifi RF noise, resulting in worse performance than them both being on the same channel.
This was one of the references from Wikipedia:
http://www.cisco.com/en/US/docs/wireless/technology/channel/deployment/guide/Channel.html#wp137283
It's better to be on the same channel than partly overlap.
shutter
Community Veteran
Posts: 22,206
Thanks: 3,769
Fixes: 65
Registered: ‎06-11-2007

Re: Wireless channel selection

@  PP how did you get that pic from inSSIDer ?  ( In easy steps... cos I have tried and not managed to do this .... )
@ ejs.... ok.... thanks for the explanation... will stay where I am then...  Wink
pierre_pierre
Grafter
Posts: 19,757
Thanks: 3
Registered: ‎30-07-2007

Re: Wireless channel selection

depends on your operating system more powerful WW7 have a screen grab that lets you outline what you want and then grab it
on my little netbook - Win7 starter, I use Prt Sc (Print Screen), that copies it to memory, than I past it into irfanview  and cut or twist as require, save to desk top and the paste it to the forum as attachment
very simple to do , but the channels do change quickly, bit hit or miss
ID
Grafter
Posts: 128
Registered: ‎08-08-2007

Re: Wireless channel selection

Also holding down the Alt key when pressing PrtScn just copies the open window, so it doesn't paste your desktop taskbar Smiley
shutter
Community Veteran
Posts: 22,206
Thanks: 3,769
Fixes: 65
Registered: ‎06-11-2007

Re: Wireless channel selection

Ah, thanks guys... will have a go and see what happens....