[ns] run 802.11b in ns2

[andrew.hy]

Hi all,  
   if i want to run 802.11b(11Mb) in ns2, do i just need to make the following changes:
   Mac/802_11 set bandwidth_   11Mb
   Mac/802_11 set dataRate_    11Mb
   Mac/802_11 set basicRate_   2Mb
   
   or do i also need to change the bandwidth of the physical layer
   Phy/WirelessPhy set bandwidth_ 11Mb
 
   should anything else be modified too?