Questions about my older Airport Extreme & 5GHz vs 2.4

I have two questions: First, how can I tell which is being sent out and how are they switched? And second, if my Airport is on the second floor but most use is on the first floor, which of the two should I be using?

Seems like three questions. 😉

Let's first find out what version of AirPort Extreme that you have. I'm assuming that you are running a recent operating system on the MacBook like El Capitan, Yosemite, Mavericks, Mountain Lion, etc.

Open AirPort Utility (Finder > Applications > Utilities > AirPort Utility)

Hold down the option key on your MacBook while you double-click on the picture of the AirPort Extreme

Look to see which Model that you have.......An 802.11n AiPort Extreme (1st Generation), or an 802.11n AirPort Extreme (2nd Generation)

Once we have that info, we'll tell you a bit more about the model that you have and how to check some settings on the AirPort that you have.

By default though, the A1143 AirPorts are set up to provide a 2.4 GHz network, so unless you have changed the settings, your AirPort is sending out 2.4 GHz signals.

5 GHz signals have faster speed capability than 2.4 GHz signals.....but.....5 GHz signals are much weaker than 2.4 GHz signals, so 5 GHz only works well when your wireless devices are in the same room as the AirPort router, or they have very close to a line-of-sight relationship with the AirPort router.

Not much of a 5 GHz signal will make it through a ceiling, which is on average about 3 times as dense as a normal wall in a home, so you would want to continue to use 2.4 GHz on your network.

A simple way to find out more about the wireless signal is to........

Hold down the option key on your MacBook while you click on the AirPort icon at the top of the screen.

Look for the Channel and that will tell you whether you are on 2.4 GHz or 5 GHz

It's going to be 2.4 GHz unless you have changed settings on the AirPort Extreme.

Locate the MacBook close to the AirPort Extreme for the next test

Hold down the option key while you click on the AirPort icon again

Look for the Transmit Rate, it might appear as Tx Rate on some versions and jot that number down. That is the maximum speed at which your Mac can connect to the AirPort Extreme.

Now move the MacBook downstairs to the location where it would normally be used and check the Transmit Rate or Tx Rate again.

See the difference in Tx Rate? That difference in speed loss would be much more pronounced if you were using 5 GHz.

So, you are going to want to continue to use 2.4 GHz for now.

Apple calls the "bars" at the top of the screen on your Mac the AirPort icon. Apple also calls this the WiFi Status Menu in some support documents.

That is amazing. Run the same checks again later and see if the results are the same.

Turn the WiFi Off on your Mac, wait a few seconds, then turn the WiFi back on.

If I get 130 Mbps close to the AirPort here and I move it a few rooms away, so the signal must pass through 3-4 walls, the speed drops to less than 50 Mpbs.

Still amazing. Your 9 year old AirPort easily outperforms my one year old product. Don't change anything.