WiFi signal strength

[TheOldPresbyope]

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Basically, I see two pairs of SSIDs with the exact same name, so since there is no signal strength indicator next to the SSID name, I could actually choose the one with the weakest signal as well.
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Sorry my explanation was so involved but, in short, what you wrote is not what is happening.

Let's say the SSID you use is "olla" so you see four instances of "olla" in the scan results. No matter which instance you select, you are telling Linux (via moOde code) simply to connect to an AP with SSID "olla". Linux chooses which of the 4 APs to connect to.

Typically the AP chosen by Linux is the one with the greatest signal strength.

For example, I have a dual-mode router with both a 2.4GHz AP and a 5GHz AP with the same SSID. Here's an edited version of what Linux detects (on a Pi3B+ which has both 2.4GHz and 5GHz WiFi transceivers but which is connected my LAN via Ethernet)

Code:

pi@moode:~ $ sudo iwlist wlan0 scanning
wlan0     Scan completed :
         Cell 01 - Address: XX:XX:XX:XX:XX:XX
                   Channel:44
                   Frequency:5.22 GHz (Channel 44)
                   Quality=70/70  Signal level=-37 dBm  
                   Encryption key:on
                   ESSID:"MYAP"
...many lines deleted...
          Cell 12 - Address: XX:XX:XX:XX:XX:YY
                    Channel:6
                    Frequency:2.437 GHz (Channel 6)
                    Quality=70/70  Signal level=-38 dBm  
                    Encryption key:on
                    ESSID:"MYAP"
 ...many more lines deleted...
...18 cells visible in total...

Here, each "Cell" represents an AP, "Address" is the same as the BSSID I mentioned before. (I've changed the actual values) and "ESSID" is the same as the SSID I mentioned before (Again, I've changed the name).

You can look up how signal level (=strength) is measured, but -37 dBm is stronger that -38 dBm.

You can run the same command from the command line of your moOde player to see these numbers for your 4 APs but your WiFi interface must not be in use. The Quality numbers are more important than the Signal level. There's information available on the InterWeb™ about this.

Regards,
Kent

PS - I'm using layman's terms in this discussion. For example, formally, "connect to" is actually "associate with"; "Cell" could represent ah-hoc cells of peers; and there's more. Let's keep it simple.