Router channels

[walt178]

I have noticed several times users recommending the router be set for specific channels Such as 1, 6, or 11.   Is there really an advantage to selecting a specific channel rather than using the AUTO select feature? 

[dslr595148]

For details of one one the reasons, i would suggest reading

http://forums.verizon.com/t5/FiOS-Internet/Why-your-Wi-Fi-is-slow/td-p/534451

The whole thread is interesting besides, the post(s) dealing with channels. They are post 2, 3, 5, and 7.

[jumpin68ny]

In a nutshell channels 1, 6, 11 are 3 non-overlapping channels and provide the best performance for a wireless LAN Network. 

[cmargolin]

You can install a free tool such as inSSIDer to show a graph of the activity and signal strength of nearby WiFi access points so you can choose the least busiest of those channels in your location for your own router.

When I got my Roku box I found that I could not connect wirelessly until I switched the router from the AUTO setting to one of the channels.

[Hubrisnxs]

Why Channels 1, 6, and 11? | MetaGeek

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Why Channels 1, 6, and 11?

One of the best things you can do to improve your 2.4 GHz Wi-Fi network coverage is choosing the proper channel for your access point to operate on. But how do you know which channel to choose?

Before we get to the selection process, let’s do a little bit of math (don’t worry- it’s easy!). 802.11g/n channels are 20 MHz-wide. When multiplying 20 times 11 (for the total number of channels), the total comes to 220 MHz. The problem, though, is that the the total space available in the 2.4 GHz is only 100 MHz.

Representation of Wi-Fi’s overlapping channels

What this means is that the channels have to overlap in order to squeeze into this space. As the diagram above shows, only channels 1, 6, and 11 don’t overlap. Overlap is bad because Wi-Fi works like a conversation– if your device hears others talking on the same channel, it’s going to wait for its turn to talk. If there are a lot of devices talking, there’s going to be a lot of waiting time. There are two main types of Wi-Fi congestion: Adjacent and Co-Channel.

Armed with the above information, you’ve narrowed your selection down to three channel choices (1, 6 and 1 1) without using any software! Using inSSIDer will help you to finalize your decision.

A screenshot from inSSIDer showing channel overlap and congestion in the channels graph.

Launch inSSIDer, and start out by counting how many networks are active on each channel. This will probably be easier to do if you click the “Channel” header to sort the channels in order. What you are looking for is the channel (out of 1, 6, and 11) that has the least amount of networks present. If there are several networks on each of these channels, you will want to choose the network whose average RSSI (signal strength) is -75dBm or lower. An RSSI at this level or below indicates that the conversations being held by the access point(s) aren’t very loud. A good rule of thumb to remember is that the closer to -20dBm a signal is, the stronger it is.

Notice in the above screenshot that the network called “dmg” is running on channel 3, which is overlapping channels 1 and 6. There is only one active network on channel 11, and its RSSI is -75dBm. If you were deciding which channel would be the best for a new access point, channel 11 has the fewest amount of networks and there aren’t any competing networks overlapping with it. This makes 11 the best channel to choose.

Using inSSIDer to help you choose which channel to run your wireless network on is one of the best things you can do to improve Wi-Fi performance, and there are also more advanced techniques for combating wireless issues.

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[walt178]

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@walt178 wrote:

I have noticed several times users recommending the router be set for specific channels Such as 1, 6, or 11.   Is there really an advantage to selecting a specific channel rather than using the AUTO select feature? 

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Let me clarify the question.  I am not asking why 1, 6, or 11 as opposed to some other channel.  My question is why manually select a channel as opposed to letting the router automatically select the best channel. Presumably that is what AUTO does.

Does AUTO select the best channel?  Using inSSIDer, it would appear so.  In my case, the number of signals shown varies roughly between8 and 20.  Most on channel 1, 6, or 11.  I did see channel 1 once.  My selection has varied between channel 1 and 6, without me having to manually make that change. It is being made automatically. And always to the least used channel.

I am a newbie in trying to understand routers beyond just plugging them in and taking what I get. So with the abundance of recommendations for manually selecting 1, 6, or 11, it seems that there must be more to it than than my smidgen of knowledge and what I am seeing in inSSIDRer.

[Hubrisnxs · Accepted solution]

auto selects the best channel at start up, but to my awareness, doesn't do well with 'on the fly channel changes'  

i.e.   if you start the router and then an hour later interference is introduced, the router doesn't do well at automatically changing it immediately and on the fly. you would restart your router and probably notice a difference.  OR you can change it manually without having to drop the whole network.

[walt178]

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@Hubrisnxs wrote:

auto selects the best channel at start up, but to my awareness, doesn't do well with 'on the fly channel changes'  

i.e.   if you start the router and then an hour later interference is introduced, the router doesn't do well at automatically changing it immediately and on the fly. you would restart your router and probably notice a difference.  OR you can change it manually without having to drop the whole network.

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That makes sense.  Auto might give me the best channel in a stable environment, but no guarantee when the environment changes.  Monitoring and manual selection will give me the best channel under any condition.

Thanks for the help. You earned a best answer.