You can configure an external DHCP server with the Ruckus WLAN system . See the basic topology diagram below.
Client will get the VLAN information from WLAN and send the DHCP discovery through the DS . The DHCP server connected in the same network will respond to the discovery massages and complete the DHCP process.
Please note that if the DHCP is in a different subnet , you would need to configure the DHCP proxy on the switch or the router .