Airport Express extension connection from Time Capsule failing

Question

I have an Airport Express extending my wifi network from a Time Capsule. The connection between them appears to fail frequently. That is, a device connected wirelessly to the Airport Express will lose internet access but will regain it when I power down the Airport Express forcing the device to connect directly to the Time Capsule. Then when I power up the Express again the device connects there and has internet access. Cycling the Express seems to re-establish a working connection between it and the Time Capsule. Is there a solution to this in the settings of either device?

Answer 1

Once you have WiFi Explorer installed on your Mac, temporarily power off the AirPort Express and locate your laptop as close as possible to the location of the AirPort Express
Open WiFi Explorer and look for the SNR heading.
SNR is signal-to-noise ratio, which is a good way to analyze connection quality. The 'bars" at the top of the Macs screen are there pretty much for show...and they tell you nothing about the noise that may be present in the signal.
Use the following SNR guide to analyze the quality of your connection at the location of the Express:
40+          Superior
35            Excellent
30            Very Good
25            Good
20            Fair
15            Low
10            Very Low
5              Not useable
A reading somewhere between 25-30 should provide a reliable connection for the Express to "extend". Things fall off quickly below 25 though, so if you see anything below that value, that indicates either too low of a signal or too much noise on the connection.
The Express can only "extend" the quality of signal that it receives, so a good SNR is critical to reliable performance.