Hello Hari,
in your network scenario the routers' interfaces are connected to the ethernet port of the radio link transceiver so physical layer (OSI 1) is always up/up as the true ethernet neighbor is the the radio link transceiver.
To understand if there are connectivity issues on the radio link that may affect the state of OSPF adjacency you can use the following show command
show ip ospf neighbor detail
that provides the OSPF adjacency uptime so you can see what is happening.
if you see that OSPF flaps you can further check with
debug ip ospf adj
to see activity on routers
I have no clue about your note about dead interval stucked for some time in show ip ospf neighbor output, However, you need to check OSPF neighborship uptime at first.
if OSPF flaps on the radio link from time to time you should consider adding an ICMP probe to check the link.
Edit: see IP SLA document
https://supportforums.cisco.com/docs/DOC-6078
Hope to help
Giuseppe