OFDM vs Frequency Hoping spread spectrum

[dervast]

Hi i am not surew i have well understand some issues about modulation schemes. I have read that the 802.16 use ofdm modulation and FHSS technique. Can someone explain what's the difference between OFDM and FHSS and how these two things cooperate?

 

[NoTime]

ODFM is how data is encoded on the carrier.
FHSS is a chanel switching algorithm.