Is your Internet connection down? Part 2

Did you read Part 1?

There can be lots of other problems with Internet connections besides those listed in Part 1. While that article dealt with problems that affect both wired and wireless connections, today we will focus on wireless problems.

Years ago when I bought my first Apple AirPort, no one else around me had a wireless Internet connection. My PC neighbors were amazed that I was able to be on the Internet without having a cable connected. Some of them eventually bought wireless set-ups of their own and they were stunned by the difficulties in setting up their new routers while my AirPort made the task so easy.

After a time things began to get ugly. Instead of being able to “see” one wireless network, I had several to choose from in my AirPort menu item. Soon I began having problems with drops in my AirPort signal strength and sometimes I could not even “see” my own network!

The problem was that all of us were using the “automatic” mode to choose which channel our wireless networks would use. I moved to a new home on a larger lot and some of the problems disappeared, but I am beginning to see a few problems once again.

If your wireless device runs on the 802.11b or 802.11g frequency, there are 11 wireless channels that we can use. Actually there are 14, but the US FCC limits us to using 11 of them. If you are in a different country, refer to this article for more information, This illustration, taken from Wikipedia graphically represents these channels.




When you choose “automatic,” your wireless router automatically chooses channel 6. One would assume that it would choose the “best” channel, but instead, wireless routers pretty much stick to channel 6.

So, if you are experiencing lots of dropouts, the first thing to do is change your channel to something other than 6. Just which channel to choose can be a bit more difficult. Looking at the illustration above, you can see that the channels overlap each other. So, the only really clear channels are 1, 6 and 11. If you live in a neighborhood with several other wireless networks in your range, it is probable that you are experiencing interference with other nearby networks.

So let’s take a look at AP Grapher, a free utility that can tell you about some of the networks in your neighborhood.

While AP Grapher automatically opens two windows, we will concentrate on the AP Scanner window.



When I opened the program, I noticed that both my network, Fauquet, and nomad were using channel 6. Clearly, both are in range of my MacBook Pro. Knowing that being on the same channel means we are interfering with each other, I chose to move to channel 1. Another choice might have been channel 11, but occasionally I can see OL085 which is using channel 9. Looking at the Wikipedia chart shown above, I might receive some interference on channel 11.

Let’s look at the differences in the readings when I am using channel 1. Everything looks about the same, but I am now seeing a second Fauquet device. That is my AirPort Express that we use to extend the range of our network, so it is not a problem. I do find it interesting that nomad has move to channel 9. I don’t know who the device belongs to, so I don’t know what caused the change.



For the moment, I plan to stay on channel 1 to see if it stops the occasional spinning beach balls that I see.

So just how do you change the channel for your wireless router? If you are using a device other than an Apple AirPort, you will need to consult your documentation. However, this is an easy project on an Apple AirPort product.

First, locate the AirPort Utility. It is in your hard drive -> Applications -> Utilities -> AirPort Utility.

When you start it, you will see this window:



Make sure you have chosen your primary device in the left column if you have more than one AirPort device. Then click the Manual Setup button.

The next window will look approximately like this one:



When you move your mouse over the label for channel, you will see it highlight slightly and a small arrow will appear. Click Channel and it will take you to the pane to set the channel:



Click on the button beside Channel and choose a channel that is not is use by other wireless networks around you. The best choices are 1, 6 or 11. If those are already in use, choose a channel that is two numbers above or below someone else’s channel.

If you live in an area will lots of wireless networks, it would probably be helpful to plan a neighborhood meeting of wireless network owners to discuss this information and to choose wireless channels for the least interference among neighbors.

Come back soon. I have some more suggestions for ways to further limit your interference from other networks.

If you are uncomfortable with making these kinds of changes to your Apple equipment, give us a call at Dr. Mac Consulting. We would be happy to take a look at your wireless network and help design a solution to minimize network interference. You can call us at 408 627-7577 or you can send an email to urgentrequest@boblevitus.com. To learn more about our services, go to our web page.

Pat

iCalInternet, Troubleshooting, WiFi