disabling 802.11b data rates on a Ruckus Unleashed setup

Today I was working on a Ruckus Unleashed setup and found out that the 802.11b data rates were enabled by default.
This allows older 802.11b clients to connect using the DSSS (Direct-sequence spread spectrum) modulation. As this costs a lot of airtime it slows down your network. 
The best remedy is to keep the 802.11b clients from your network. 
Remember though, the RF spectrum is a shared medium. So if any 802.11b client is communicating with some neighboring ap nearby it still influences your network performance.

First confirm your current settings (marked in yellow):

ruckus# show wlan all
WLAN Service:
  ID:
    1:
      NAME = CustomerSSID
<cut>
      OFDM-Only State = Disabled
<cut>

 To disable the 802.11b data rates issue the follwing commands:

ruckus# config
You have all rights in this mode.
ruckus(config)# wlan CustomerSSID
The WLAN service 'CustomerSSID' has been loaded. To save the WLAN service, type 'end' or 'exit'.
ruckus(config-wlan)# ofdm-only
The mgmt-tx-rate will be set to 6Mbps due to ofdm-only enable.
The command was executed successfully. To save the changes, type 'end' or 'exit'.
ruckus(config-wlan)# end
The WLAN service 'CustomerSSID' has been updated and saved.
Your changes have been saved.
ruckus(config)#

If you show your wlan SSID again you will see:

ruckus# show wlan all
WLAN Service:
  ID:
    1:
      NAME = CustomerSSID
<cut>
      OFDM-Only State = Enabled
<cut>

Note: This is configurable on a per SSID basis