[ns] How to get SNR information at phy/MAC layer

[Abraham George]

Hello, 
  Can someone  please help me on how to get the SNR  in NS-2. I guess it is done at the Physical layer, i want the SNR value, which i will use it for handoff at the network layer. Is a there model or where do i access the code to get this value. Please help.

Thanks,

Abraham George