in practical use it's really not necessary, since a lot of those apartments are small enough in square footage to be well covered by one $80 5.x GHz capable 2x2 or 3x3 802.11ac AP. You can still get 400-700Mbps speeds through a 5 GHz channel, such as around 5150MHz, on any dual band equipment. Although 5 GHz goes through wood framed walls/floors a tiny bit, it doesn't go very far, to the point where you might see your neighbor's 5 GHz AP at a signal of -87.
Funnily enough, I seem to get 5 GHz interference from nearby buildings through glass. I’m very much looking forward to 6Ghz. I ran some 60Ghz radios for a bit, and that was great, as it was interference free, and a drywall layer would stop it.
Unfortunately, the hardware failed, and I didn’t see mass adoption of 60Ghz elsewhere. I hope that tech like local optical or 60Ghz becomes viable.
Yep that is definitely a thing, and you will see more of it coming in through glass in the 5725 to 5850 band, since APs can run at higher power in those frequencies. One possible mitigation is to choose the cleanest possible channel for your in home use in the bands where FCC-allowed equipment can only transmit at moderate powers (specifically disallowed for outdoor WISP 5 GHz equipment too), in the area of 5100 to 5300.
> I hope that tech like local optical or 60Ghz becomes viable
Yeah, I was really fond of the prototypes a while back that used visible light; those would completely end contention in an apartment complex or office:)
One of my neighbors has a 5 GHz access point that comes into my house stronger than the one in my own home. My only theory is they have a high powered AP with a directional antenna pointed in my direction. They also run 3 other APs on other channels as far as I can tell with identical. Basically they use almost all the available spectrum in the 2.4 GHz & 5 GHz range.
