RTS CTS Coordination

[John Does]

Hello  everybody  !!!

I need your help for implement RTS-CTS coordination mechanism in wsn. 

Scenario

suppose that we have 4 nodes S , A , B and C.

 in first step S send a RTS packet to A, B , C

in segong A, B and C respond by sending a CTS packet

and when node S receive the first CTS, him respond by sending the data packet to the sender.

I am some pictures for better understanding. 

I want to know how i can implement that  in mac layer in ns3

thank !!!