Multiple APs on same subnet

Hi, I’d like some advice on setting up this scenario.
I’d like to set up 4 AP’s(Large area ~ 100meters between points in a square shape) using same SSID & Encryption password, and run off the same subnet .
I’d like the end users to be able to use 1 SSID to sign in with, but for them not to notice them shifting to another AP as they move around the area.
Thoughts ??

[ADSL]–[MIKROTIK ROUTER]–[SWITCH]—[4 AP’S] ???

should work.

I have a few sites setup like that with 2011’s or 751s and it works well, with staggered frequencies. I am assuming you’re talking about 2.4ghz so in that case I use only 2417, 2437, 2457 as many apple products seem to be flaky on 2412/2462. When I have to reuse frequencies I set use them where the APs are least likely to see each other (distance, obstacles) and turn the power down a bit. WDS has always been too slow/high latency for my deployments and either a 5.8ghz back-haul or ethernet has been viable.

Will I need to use different frequencies for my AP’s or can I keep the same channel ? Whats the effect on the end user devices ?

I’m not really versed with this but from my understanding when using 802.11b/g/n there are two different kinds of roaming between access points:
WDS where they can connect using the same frequency/ssid/etc and the AP’s can talk to eachother over the same radio (no ethernet connection between them or second band necessary)
Different channels, same SSID, same authentication, client chooses AP to talk to (strongest signal I think)
In the second scenario (no clue what it is called) the client needs to be able to see the signal of the neighbouring access points so it knows when it needs to switch to the next AP. It is up to the client to choose when to do it. To properly see the other access point without it acting as interference, it would need to be on a non-overlapping channel. Atleast where I am, there isn’t much bandwidth (in terms of available frequency ranges) available, so I stick with those three and it works for me.

If WIFI client is smart enough - better option for speed would be the use of non-overlapping channel use. Client will decide when to go to stronger signal AP and maintain a higher speed in communication. As praeses wrote in his post.