I have an office which consist of 4 floors and i want to setup wireless in such a way that the client will not disconnect even if it will roam from ground floor to till last floor (If i am not wrong, this concept is called wireless roaming?)
What kind of hardware i need, please mikrotik tested hardware only? and please also explain me the configuration.
This has been covered many times. It all depends on your requirements
If you can wire each ap to a central switch, simply set the ssid the same on all devices, but change the channels so that neighboring aps are at least 5 channels apart. Your device will switch aps as you move around the building. Its not seamless, but takes less than a second.
If you need to use wireless wds links, it wont perform well at all as the device will not switchwhen you think itshould.