MIB selection - Capacity and utilization

Hello all -

We are looking to monitor the overall capacity of the sectors via MIBs using our What's Up server.  I have the MIB for the  "AirTime Utilization" (. but that only gives us half the story.   The other piece of this would be the Modulation Rate per SM.  I can not seem to find that MIB anywhere.  We also grab the actual throughput through a standard 'interface utilization' MIB 

Or am I thinking us this all wrong.  I welcome any ideas  or strategies that are currently in use  that seem to work well for other operators!