OSPF in a single ip class

Hello,

I have a network with valid ips in each routerboard, all of them goes for one single gateway. What I need now is increase my bandwidth.
Today I get through my PTP 45 Mbps in 5ghz at 27km. I wanna get 90 Mbps by using OSPF, now with two 34 dbi dishes.
I’m not an advanced user, so How do I do the config with just one ip class?

Thank you.