My ISP gave me a cable model/wifi router that sucks. It's wifi performance is much worse than my old decade old DSL/wifi router. So I thout of using an access point. But my router is in the basement and the antennas of cieling-mount access point head down. Can I use one RE603X (NOT RE650! RE603X was not in the drop down) in access point mode in the basement and another in range extender mode on the main floor to create a mesh network (single SID)? I don't need a router, I only need an access point.