This is mostly a curiosity question to people who know more about radio and wi-fi than I.
The 2.4Ghz band is massively overpopulated near my house to the point of sometimes getting >1000ms pings to the router from only a few feet away. inSSIDer finds at least 10 broadcasting SSID's within around 15 seconds of starting, so this isn't a real surprise to me! Sometimes I can get good results by changing the channel to something like 3 or 8, but it's usually temporary as the others use Auto Channel and hop around.
Now, the router I have is capable of 5.0Ghz, as is the laptop I type this on. Switching to 5.0Ghz gives superb results: I can download at ~90Mbps and get consistent 1ms pings. The problem is that only this laptop supports 5.0Ghz!
My question: Would I still get decent 5.0Ghz performance if I place a 2.4Ghz access point directly next to my router? And, indeed, will 2.4Ghz continue working as 'normal'? Testing would be an obvious step, but I threw all my superfluous equipment out in a recent house move.
My understanding is that I should get good performance, certainly in comparison to having two devices using the same frequency range, but I do believe there will be some impact by the virtue of them being directly next to each other.
(Cabling is not an option due to it being a rented house)