WiFi Phy simulator and MAC Test suite

Hi

I am looking for setting up an environment to test MAC 802.11 implementation at Station side. ( Conformance test environment). Is there any open source tool that can be used for the same. I had look at NS2 but is not upto my satisfaction .

I am trying to write MAC test suite to test following procedure in MAC 802.11 STA side:
- Prop
- Association
- Auth &
- Short and long frame tx.
- Simulation of data packet collision and checking the retransmission procedure of the MAC implementaton.