[kopijahe]

In topic of building a multi-AP but with same SSID wifi network: Do I choose the same channel too or not?

I have a wifi networks on a building built with brick and mortar, so I need more APs to cover the entire premise, there gonna be some overlaps in the coverage here and there...

[hunter2_]

No, set every AP to use the quietest channel. Using something like Wifi Analyzer on a phone positioned where the AP will be but with the AP off, see what's got the least going on... any loud APs on the same channel whether they're yours or not would be detrimental. Also completely avoid overlap. On 2.4 GHz that means 1, 6, 11.

Also, if there will be so many APs that they will share channels, you want the APs physically isolated from each other even if that means a little more isolation between AP and client than you'd otherwise have. For example, in a hotel or dorm put an AP in every third room instead of all in the hallway, so they don't hear each other.

[el_isma]

Some APs let's you lower transmit power, which will help in isolating them