Hi. I'm afraid you guys may have a small confusion here.
The wAP LTE is a wifi access point for local devices (laptops etc) which uses LTE modem with sim card as "source of the internet".
That's a bit (although not fully) within the area of what the OP Krzysztof is looking for.
But I believe Tom here hijacked this thread because he is still urgently looking for point to point wireless link hardware to replace the discontinued MT 900MHz gear.
2.4/5/60 are no bueno because there's no direct line of sight (trees), and 900MHz worked through the obstruction.
@Krzysztof, btw - if you can't run new cables in the building, maybe consider the PWR-LINE products?
https://mikrotik.com/products/group/dat ... powerlines
It's not a true "mesh system" but if you want MT, this could be a way to go, I think.
There are three variants. Two slower ones, one with an AP inside the plug and one allowing you to hang one of the small MT accesspoints on the USB cable.
The PRO is higher speed (but probably requres a little better quality power cabling) and does MT-style passive PoE injection on the ethernet port, so you can connect a big modern MT AP like the hAP AC2 or cAP AC and it'll have both power and high speed uplink.
Alternative would be to decide to dedicate one of the two frequencies (2.4 or 5.0) as "backhaul", have a central access point listening on it, and have all other APs connect to the central as clients (while broadcasting the other frequency as AP for your devices to use).
In either case, put a beefier Routerboard or such as the core of your network, configure CAPsMAN and manage all the access points via it.