I never heard of a tri-band router before. It's a misnomer because there is no third band, it just means it can handle 2.4GHz but will use two channels of 5GHz at once. There have been other routers in the past that used more than one channel but it sounds very selfish to use in a dense apartment/condo living situation.
Well luckily there is a massive chunk of 5ghz channels that nobody is using right now so i'm okay, and the routers that use the 2 bands of 5ghz actually will step down to only 1 if they see someone else stepping on either of them.
But just the fact that the higher end routers handle the extra congestion much better was more the point.
'Power Line' or similar adapters can work quite well in apartments. You can use it for a wired connection where practical, and otherwise have a couple 5GHz routers for a good wireless access.
If they haven't done so already, maybe we'll see copper-clad drywall or flooring for such environments ? Guess that would take down cellular service too though.
Reducing transmit power reduces interference, but it also reduces capacity since the received power (and hence the SNR at the receiver) is reduced! The Shannon limit on channel capacity dictates exactly how much bit rate (C=B*log2(1+SNR)) is achievable over a channel. SNR is a fundamental ingredient of this equation.
Also, copper is pretty expensive. A mesh of cheaper metal should do the job; might even be possible to tune it to the right frequency so you don't block cellphones, but I don't know
My wifi is fine between one wireless device and a wired device, but if I'm say, using my laptop to beam a video off my NAS onto my TV, it all breaks down.
not really, as I believe any router that uses more than one channel at once must disable that feature if there are any other APs that are trying to use any of those channels.