Why the wifi in the shed is probably unreliable / 2022-02-25

I used the raspberry pi in the shed to do a wifi scan, to get an idea of the usage of the 2.4 GHz wifi band as seen in the shed.

This finds 18 to 22 networks, with our own network not as the strongest network. As you can imagine most channels have multiple networks on them. And the overlap in wifi channels makes this worse: the networks on channel 2 see interference from those on channel 1.

From the list of networks, with names and address information removed, just leaving signal strength and channel / frequency:

-93 dBm, ch   1, 2412 MHz
-91 dBm, ch   1, 2412 MHz
-92 dBm, ch   1, 2412 MHz
-72 dBm, ch   1, 2412 MHz
-92 dBm, ch   1, 2412 MHz
-88 dBm, ch   1, 2412 MHz
-92 dBm, ch   1, 2412 MHz
-91 dBm, ch   2, 2417 MHz
-80 dBm, ch   2, 2417 MHz
-90 dBm, ch   3, 2422 MHz
-94 dBm, ch   4, 2427 MHz
-93 dBm, ch   5, 2432 MHz
-94 dBm, ch   5, 2432 MHz
-80 dBm, ch   6, 2437 MHz
-94 dBm, ch   8, 2447 MHz
-95 dBm, ch   8, 2447 MHz
-94 dBm, ch   9, 2452 MHz
-95 dBm, ch   9, 2452 MHz
-77 dBm, ch  10, 2457 MHz
-84 dBm, ch  11, 2462 MHz
-93 dBm, ch  11, 2462 MHz

This is a right mess. If I ever want reliable wifi in the back garden/shed I will have to have an extra access-point there. This option of having wireless vlan(s) available in the shed has influenced the choice in switch for the shed.