Should I expect full signal strength right next to the Express locations (regardless of throughput)? Both are placed in area's where the Extreme's wifi reach is good.
In theory, yes. You should expect to see strong signal strength near the base station ... and, you are correct, that it may not necessarily be directly related to the throughput available.
Since you don't have a laptop handy, we may be able to use your iPad or iPhone instead. I am still researching to see if there is an app out there that can provide SNR measurements, but have not found any as of yet.
One option, is to enable the Wi-Fi Scanner option in the iOS version of the AirPort Utility.
To do so:
- Tap on Settings
- Tap on AirPort Utility
- Enable the "Wi-Fi Scanner" option.
- Exit Settings, and then, tap on the AirPort Utility to run it.
- In the upper right hand corner you should now find the Wi-Fi Scan option in blue.
- Tap on Wi-Fi Scan
- Leave the scan duration set to: Continuous
- Tap on Scan
- After a few moments, any Wi-Fi network that the AirPort Utility finds will be listed.
- You want to look at two specific items:
- The MAC address of your base station. They are unique for each base station.
- The RSSI value. This value represents the Wi-Fi signal strength as it is perceived by your iPad/iPhone. The less negative the number, the stronger the signal. FWIW, I was getting readings around -45 dBm near my 802.11ac AirPort Extreme.
- Tap on Stop to discontinue the scan.
Again, this is not ideal as it only shows the perceived signal strength at the wireless client (the iPad or iPhone in this case). It does not show the amount of Wi-Fi signal noise in the same area. Together these two values would give you the Signal-to-Noise Ratio (SNR). One method of determining signal quality.
What I suggest, at this point, is to take these measurements as follows:
- Temporarily power-off the Express. Leave only the Extreme running.
- Using your iPad/iPhone, note the RSSI values at the following locations:
- Near the Extreme.
- Near the location of the Express.
- Just outside where the Express is located.
- At the location you want Wi-Fi coverage in the garden.
- Power-up the Express.
- Again, using your iPad/iPhone, note the RSSI values at the following locations; however, this time be sure to note the MAC address values as they will be different depending on whether your iOS device is connected to the Extreme or the Express. You want the values for the Express.
- Near the location of the Express.
- Just outside where the Express is located.
- At the location you want Wi-Fi coverage in the garden.
Please post back your results.