Channels

At the Geocache location you can find at least 30 different wireless networks from the surrounding apartments. Surprisingly all of the networks are encrypted with WPA2 - except the public hotspot provided by the city of Linz.

The 2.4GHz spectrum is really packed. On the contrary, you barely find 5GHz networks outdoors. Even inside my apartment, I could find a lot of overlapping networks in the 2.4GHz band. I think the 5GHz is more suitable for populous areas, where nearly everyone has his own wireless router. The walls shield most of the 5GHz signals, so you don't run into any interference problems of overlapping channels.

The router

The TP-Link router was located inside of our living room on the 4th floor. The signal was strong enough, that you could read the network name from the sidewalk. I could observe that some Geocachers were inspecting a nearby streetlight - maybe they thought the signal came from there ;)

Long SSIDs

A SSID can contain up to 32 octets. Some older devices had problems with the length of the SSID. These weren't technical problems, but their displays where too small, so the people could not read the full coordinates.