I need an advice for which wireless devices to use for Public hotspot wifi for phones, that as much coverage as possible, approximately 500 clients will be connected, and each client will use 2Mbit/s, I'm planning to use mainly 2.4Ghz devices
Just off the top of my head, a couple of pointers you’d have to consider to save yourself from anguish or frustration down the line, regardless of the vendor (Mikrotik or other vendor ) you select for the WiFi service you intend to provide.
What are you trying to achieve / do – provide commercial public WiFi hotspot service (outdoor, I suppose) for your community or provide WiFi hotspot service for a one-off event (outdoor/indoor)?
What’s the area (measurement of the area) you intend to cover and its characteristics—outdoor/open air or an indoor event centre?
Based on the requirements you establish, you’d have to undertake a WiFi design to determine how many APs and types (and vendor you select) you require to cover the area you intend to serve.
Since I see you mentioned or focused on ‘transmit power’ it seems you intend to ‘blast’ the area you intend to cover with as much power as possible to reach the target clients. Anyway, sorry to disappoint you, but in that case the low-power WiFi client devices (mostly handheld smartphones and tablets) will ‘hear’ the central AP that you intend to mount far away alright, but the AP won’t hear the lower-power signals transmitted from the client devices. Moreover, you’d just end up ‘polluting’ the RF environment where you are.
I’d suggest you also design your network topology and test in a lab, then pilot first before rushing off to implement. Your network design should also include how to backhaul the APs to where you receive your upstream internet feed? Also some of the design considerations should be what IPs you’d assign (IPv6?) or you’d NAT the client IPs you assign? Also how you’d control/regulate use of the WiFi – signing up of accounts and bandwidth use