Mesh for dummie

Hi guys,
I've just installed openwrt on my old netgear wndr3800. I want to use it for sqm qos with my fritzbox 7530. I have successful setted up with fritz as modem, what i want to do now is using my fritz mesh extender with the netgear router. Can i? I mean, can i use them in 'mesh mode'? I do not know if i need some specific harware to run a mesh network and if i can combine fritz extender with openwrt. Sorry for the noob question, but this is my first openwrt day :slight_smile: