A network operator can implement bandwidth limits per user when using WPA2-Enterprise with RADIUS authentication. This functionality requires the use of RADIUS Group Policies.
You will then need to setup a corresponding group within your Directory server and ensure that the intended user or computer accounts are members of that group. Finally you will need to specify this group and Filter-ID attribute in your RADIUS servers policy. Please refer to your RADIUS server manual for more details on this portion of the setup.
The following Microsoft link explains creating a Filter-ID attribute on an IAS server.