I thought this comment was put in 
  previously.  Here it is...
The current text 
  states:
A cryptographically 
  generated challenge-response authentication mechanism for the user to 
  authenticate the network and for the network to authenticate the user must be 
  used.
I suggest that we change this to read:
A cryptographically generated challenge-response 
  authentication mechanism for the network to authenticate the mobile station 
  shall be used.  Mechanisms for the mobile station to authenticate the 
  network shall be optional.
Rationale:
In section 4.1.16.1, 
  the text seems to read that both authentication directions are required.  
  Since 802.20's scope is licensed operation, the likelihood and problems 
  associated with rogue base stations (or rogue APs) is minimal.  The 
  required direction for authentication is from network to mobile station, so 
  that network security is maintained and theft-of-service for the license 
  holder is minimized.
  ..................................................................................
                  James 
  D. Tomcik
                  QUALCOMM, 
  Incorporated
                  (858) 
  658-3231 (Voice)
                  (619) 
  890-9537 (Cellular)
                  From:  
  San Diego, CA
                  PGP: 
  5D0F 93A6 E99D 39D8 B024  0A9B 6361 ACE9 202C 
  C780
..................................................................................